JP2003228031A - Optical circuit component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical circuit component which has high thermal separating performance between optical waveguides, can decrease the distance between the optical waveguides, and can be made small-sized and highly integrated. <P>SOLUTION: A clad layer 2 is provided on a substrate 1 and two cores 3a and 3b are provided in the clad layer 2. Thin-film heaters 5a and 5b are provided in an area including areas on the top surface of the clad layer 2 right above the cores 3a and 3b. Further, a radiator 8 is provided on the top surface of the clad layer 2. The radiator 8 is of a comb shape surrounding the thin-film heaters 5a and 5b and a portion of it is formed in an area 9 between the cores 3a and 3b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical circuit component provided with at least one thermo-optical phase shifter on a substrate, and more particularly to an optical circuit component with improved thermal isolation.

[0002]

2. Description of the Related Art In the field of optical communication,
Wavelength Division Multiplexing (WDM)
xing) is rapidly being promoted by the advent of communication methods. Around 1990, when the wavelength division multiplexing communication system was first developed, the number of wavelength division multiplexing was about 4 to 16 wavelengths.
At present, although it is at the research level, the number of wavelength division multiplexing continues to increase at a momentum reaching 300 wavelengths. Although the communication capacity increases dramatically as the number of wavelength division multiplexes increases, functional control is performed for each of these multiplexed wavelengths, for example, the power of each wavelength is made constant or wavelength conversion is performed. In order to carry out the control, the number of optical elements corresponding to the number of wavelengths becomes necessary. For this reason, as in the conventional method, the method of preparing a separate device for each wavelength of light causes problems such as an increase in the installation area of the device and the total price.

Therefore, recently, an optical circuit component for controlling a plurality of lights having mutually different wavelengths has been under development, and a high level for controlling input / output of a plurality of lights to such an optical circuit component has been developed. There is a growing need for optical switches that can be densely integrated.

Conventionally, a single optical switch has been realized. Also, a matrix switch having a large number of this single optical switch and having a plurality of input / output ports has been put into practical use. Techniques for realizing an optical switch include the method of using a thermo-optical phase shifter, the method of mechanically connecting the input port and the output port, and the method of rotating the movable mirror to a desired angle to input and output ports. A wide variety of technologies have been developed, such as a method for connecting to and output, and a method for changing the connection between input and output ports by controlling the reflection of light by means such as generating bubbles at the intersections of cross-connected waveguides. Has been done. These conventional techniques are disclosed in, for example, Japanese Patent Laid-Open No.
-5653, JP-A-62-187826,
It is disclosed in Japanese Patent Laid-Open No. 2001-255474.

Among these conventional techniques, the planar lightwave circuit (PLC) type device using the thermo-optic phase shifter can be manufactured easily because the semiconductor circuit manufacturing technology can be used in the manufacturing process thereof, and the integration is extremely high. It is excellent and has the feature that it is also advantageous for high-performance and large-scale optical switches.

Generally, the thermo-optical phase shifter is realized as follows. An optical waveguide including a clad layer and a core is produced, a metal thin film or the like is formed on the optical waveguide, and the metal thin film is processed into a thin line shape along the optical waveguide so that electricity can be supplied. Then, when electric power is applied to the metal thin film from the outside, heat is generated due to the electric resistance of the metal thin film and functions as a heater for the optical waveguide. The heat generated in this heater is conducted through the cladding layer of the optical waveguide and reaches the core,
The refractive index of the material forming the core is changed. For example, when the optical waveguide is formed of quartz glass, the temperature coefficient (dn / dT) of the refractive index of quartz glass is about 1 × 10.
^{Since it is −5} (/ ° C.), heating the core increases the refractive index of the core. As a result, the effective waveguide length of the optical waveguide becomes longer, and the phase of light at the output end shifts. By changing the output of the heater, the phase shift amount of light at the output end can be arbitrarily controlled.

Two sets of such thermo-optical phase shifters are provided,
A Mach-Zehnder interferometer can be produced by connecting the input ends of these thermo-optical phase shifters to each other by, for example, a 3 dB coupler and connecting these output ends to each other in the same manner. In the Mach-Zehnder interferometer, the input light is branched into the optical waveguides of the two sets of thermo-optic phase shifters, and an arbitrary phase difference is given between these branched lights, so that the output end The light that has passed through each optical waveguide in the coupler is made to interfere,
The output intensity according to the phase difference can be obtained. For example,
When the phase difference is not provided (phase difference 0), the lights interfere with each other so as to strengthen each other, so that no difference appears between the input light and the output light. On the other hand, when the phase difference is set to a half wavelength of the input light wavelength (phase difference π), the lights cancel each other at the output end, and the output light can be extinguished. That is, the Mach-Zehnder interferometer can be operated as an optical switch by changing the phase difference of the branched light between 0 and π. A matrix switch having a plurality of input / output terminals is realized by using many Mach-Zehnder interferometer switches. Such a matrix switch is described in, for example, "T. G.
oh, "High-Extinction Ratio and Low-Loss Silica-Bas
ed 8x8 Strictly Nonblocking Thermooptic Matrix Swi
tch ", IEEE J. Lightwave Technol. Vol.17, p.1192 (1
999) ”.

However, in the Mach-Zehnder interferometer, there is a problem that the heat generated in one thermo-optical phase shifter affects the operation of the other thermo-optical phase shifter. In addition, when a plurality of Mach-Zehnder interferometers are provided on the same substrate, and when a Mach-Zehnder interferometer and other optical circuits are provided on the same substrate, the Mach-Zehnder type is used. There is a problem that the heat generated by the thermo-optical phase shifter of the interferometer affects the operation of the adjacent Mach-Zehnder interferometer and other optical circuits. Further, in the vicinity of the thermo-optical phase shifter, for example, an LS that controls the heater of the thermo-optical phase shifter.
I, or if a laser oscillator or the like is provided, the heat generated from the heater may affect the operation of the LSI, and the heat generated from the laser oscillator may affect the operation of the thermo-optical phase shifter. There is.

Therefore, conventionally, the heat generated from the heater of the thermo-optical phase shifter does not affect the operations of the optical waveguides of other thermo-optical phase shifters, the optical waveguides of the adjacent Mach-Zehnder interferometers and other optical circuits. As described above, a simple method for realizing thermal separation has been adopted by sufficiently increasing the distance between these optical waveguides.

Further, as a more active method, "Akira Himeno et al.," Single-mode optical waveguide gate matrix switch using silica-based waveguide ", IEICE Transactions C, Vo
l. J71-C, No. 5, pp. 685-691 (19
1988)). FIG. 19 is a perspective view showing a Mach-Zehnder interferometer using this conventional ridge-type waveguide. As shown in FIG. 19, in this Mach-Zehnder interferometer, an optical waveguide 102 is provided on a substrate 101. In the optical waveguide 102,
An input terminal 103 and an output terminal 104 are provided,
The input terminal 103 and the output terminal 104 are branched into two optical waveguides 105a and 105b. In addition, the optical waveguide 1 viewed from the optical waveguide 105a on the substrate 101
A heater 106 is provided on the opposite side of 05b. Furthermore, the optical waveguides 105a and 105b on the substrate 101
Between the optical waveguide 105 and the optical waveguide 105b.
A heat-dissipating metal film 107 is provided on the opposite side of a.
As a result, when the heater 106 heats the optical waveguide 105a, the heat is dissipated by the heat-dissipating metal film 107, so that the heating of the optical waveguide 105b can be suppressed.

Further, for example, "A. Sugita et al.," Bri
dge-Suspended Silica-Waveguide Thermo-Optic Phase
Shifter and Its Application to Mach-Zender Type Op
tical Switch ", Trans. IEICE, 73 (1990) p.105", two arm waveguides are provided on the substrate, and a groove is provided on the substrate between the two arm waveguides by dry etching or the like. A technique for filling the inside of the groove with a gas having a low thermal conductivity such as the atmosphere is disclosed. As a result, the thermal isolation between the two arm waveguides can be improved.

[0012]

However, the above-mentioned conventional techniques have the following problems. In the technique of increasing the distance between the optical waveguides, there is a problem that the total size of the optical circuit components becomes extremely large as the number of optical waveguides increases. In order to reduce the size of the optical circuit component, it is necessary to reduce the distance between the optical waveguides, and it is necessary to reduce the thermal crosstalk between the optical waveguides by some method. As described above, the number of channels has increased dramatically in recent years, and the number of optical waveguides in optical circuit components has increased with the increase in the number of channels. Is not practical.

Further, in the method shown in FIG. 19 in which a heater is provided outside the branched optical waveguide and a metal film for heat dissipation is provided between the waveguides, since the heater is placed outside the optical waveguide, they are adjacent to each other. There is a problem that heat transfer to the optical element becomes large, which is not suitable for arraying and miniaturization. That is, in the Mach-Zehnder interferometer shown in FIG. 19, the heat generated by the heater 106 is generated by the optical waveguide 105.
Although it can be prevented to reach b to some extent, heat transfer to an optical element (not shown) arranged on the opposite side of the optical waveguide 105a from the heater 106 becomes large,
It affects the operation of this optical element. Also, the heater 106
The heater 10 is formed directly on the substrate 101.
There is also a problem that the heat generated by 6 escapes directly to the substrate 101 and the heating efficiency of the optical waveguide 105a is low.

Further, in the method for providing heat isolation by providing a heat insulating groove around the optical waveguides, since a substance having a low thermal conductivity such as the atmosphere is arranged between the optical waveguides, the distance between the optical waveguides is greatly increased. Can be narrowed to However, when the substrate is made of a material having a low thermal conductivity such as quartz glass, the heat generated from the heater provided in the thermo-optical phase shifter is
The heat is transferred to another optical waveguide through the substrate. At this time, since the heat insulating property of the substrate is high, the transferred heat is accumulated in the substrate and the temperature of the entire substrate rises. As a result, the temperature of the other optical waveguide rises, and heat separation cannot be achieved. In addition, such a heat insulating groove structure,
In principle, there is a problem that it cannot be applied to a case where a temperature distribution is desired to be provided in the core of a slab type waveguide or the like, or when the substrate is made of a material that is difficult to etch.

The present invention has been made in view of the above problems, and has a high heat separation performance between optical waveguides or between adjacent optical circuits, and between optical waveguides or between adjacent optical circuits. It is an object of the present invention to provide an optical circuit component which can be reduced in distance and can be miniaturized and highly integrated.

[0016]

An optical circuit component according to the present invention comprises a substrate, a clad layer provided on the substrate, and a clad layer which is separated from each other in a direction parallel to the surface of the clad layer. A plurality of cores that are provided together to form a plurality of optical waveguides together with the clad layer, and are provided in a region including at least one region directly above or immediately below the cores to change the phase of light in the optical waveguides by generating heat. And a radiator provided in a region between the cores or in a region directly above or directly below this region for absorbing heat emitted by the thin film heater.

In the present invention, the thin film heater heats the core provided in the region directly above or below the thin film heater,
It is possible to change the phase of light in the optical waveguide composed of the core and clad layers. At this time, since the thin film heater is provided in the region including the region directly above or directly below the core, it is possible to suppress the heat of the thin film heater from leaking to other cores, and the thin film heater is provided in the region directly above or below this thin film heater. It is possible to efficiently heat the existing core. In addition, the radiator provided in the region between the cores or in the region directly above or directly below this region absorbs the heat generated from the thin film heater, and this heat can be suppressed from being transmitted in the region between the cores. It is possible to prevent the heater from heating the core which is not located immediately above or below this thin film heater. This can improve the heat separation between the cores. As a result, the distance between the cores can be reduced, and the optical circuit component can be downsized, highly integrated, and large-scaled.

The number of the cores may be two, and the input ends of the cores may be connected to each other and the output ends of the cores may be connected to each other. Thereby, a Mach-Zehnder type optical interferometer can be formed. In this Mach-Zehnder interferometer, the interference of light at the output end is controlled by adjusting the difference between the phase of the light in one optical waveguide and the phase of the light in another optical waveguide, The intensity of the light output from the end can be arbitrarily adjusted within the range of 0 to 100% of the intensity of the light input to the input end. Thereby, for example, VO
An element for adjusting the intensity of output light, such as A (Variable Optical Attenuator), can be formed. Also,
In such a Mach-Zehnder interferometer, the phase of the light of the one optical waveguide and the phase of the light of the other optical waveguide are made equal to each other, so that the lights are strengthened at the output end, The same light as the light input to the input end can be output from the output end. Alternatively, by making the phases of the lights different from each other by 180 °, it is possible to cancel the lights at the output end and to cancel the light output from the output end. Thereby, an optical switch can be realized.

Further, a groove may be formed in at least a part of a region between the cores in the clad layer. This prevents direct heat transfer from the thin film heater to the core not directly above or below the thin film heater, and also suppresses indirect heat transfer through the substrate, further improving heat separation. And the power consumption of the thin film heater can be suppressed. Also, the optical characteristics can be improved by releasing the stress applied to the core and the clad layer.

Another optical circuit component according to the present invention is an optical circuit component arranged adjacent to a device, wherein the substrate, a clad layer provided on the substrate, and the clad provided in the clad layer are provided. Between the core and the device, a core that constitutes an optical waveguide with a layer, a thin film heater that is provided in a region including a region directly above or below the core and that changes the phase of light in the optical waveguide by generating heat, And a radiator provided in a region directly above or below this region for absorbing heat emitted by the thin film heater or the device.

In the present invention, the thin film heater can heat the core and change the phase of the light transmitted through the optical waveguide. At this time, since the thin film heater is provided in the region including the region directly above or directly below the core, the heat of the thin film heater can be suppressed from being transferred to the device, and the core can be efficiently heated. Further, since the radiator is provided in the region between the core and the device or in the region directly above or directly below the device, this radiator absorbs the heat generated by the thin film heater, so that the heat generated by the thin film heater heats the device. And heat generated by the device can prevent the core from heating. This can improve the thermal isolation between the core and the device. As a result, the distance between the core and the device can be reduced, and the optical circuit component can be downsized, highly integrated, and large-scaled.

Still another optical circuit component according to the present invention is a substrate, a clad layer provided on the substrate, a slab type core provided in the clad layer and forming an optical waveguide together with the clad layer. One or a plurality of thin film heaters provided separately from each other in a direction parallel to the surface of the cladding layer in a region directly above or below the core to heat the core unevenly in the width direction thereof by generating heat; A radiator provided in a region between the thin film heaters or in a region directly above or directly below this region, and which absorbs heat emitted by the thin film heater.

In the present invention, the thin film heater can heat the core non-uniformly in the width direction thereof to locally change the phase of light in the optical waveguide. At this time, since the thin film heater is provided in the region directly above or directly below the core, the core can be efficiently heated. Further, since the radiator is provided in the region between the thin film heaters, or in the region directly above or directly below it, it is possible to prevent the heat generated from the thin film heater from heating the portion other than the region directly above or directly below it. . This can improve the thermal isolation between the core parts. As a result, a fine refractive index distribution can be formed in the core with good controllability, so that the optical circuit component can be made highly functional and miniaturized.

The clad layer has a lower clad layer formed on the substrate, and an upper clad layer formed so that its lower surface is in contact with the upper surface of the lower clad layer. The core is preferably in contact with the interface between the lower clad layer and the upper clad layer. Thereby, the symmetry of the clad layer in the vicinity of the core can be enhanced, and the polarization dependence of the optical characteristics can be suppressed. Therefore, it is not necessary to consider the deflection of the light input to the core, and the optical circuit component can be highly functionalized, miniaturized, and scaled up without deteriorating the optical characteristics.

Further, the thin film heater may be formed on the clad layer. Thereby, the heat generated by the thin film heater can be suppressed from escaping to the substrate, and the heating efficiency of the core can be improved. Further, the production of the optical circuit component is facilitated, and the yield can be improved.

Alternatively, the thin film heater may be formed in the clad layer. As a result, the thin film heater can be stabilized, the distance between the thin film heater and the radiator can be increased, and the amount of heat directly transferred from the thin film heater to the radiator can be reduced. Can be suppressed.

Furthermore, the radiator may have a heat absorbing portion for absorbing the heat emitted by the thin film heater and a heat radiating portion connected to the heat absorbing portion for radiating the heat absorbed by the heat absorbing portion. Of course, the heat absorbing portion may be embedded in the clad layer, and the heat radiating portion of the radiator may be exposed to the outside of the clad layer. This increases the degree of freedom of the radiator placement position, and
The heat radiation efficiency of the radiator can be improved.

Furthermore, the optical circuit component of the present invention may have a via formed inside the cladding layer to thermally connect the heat absorbing portion and the heat radiating portion of the radiator. As a result, the heat absorbing portion and the heat radiating portion of the radiator can be flexibly arranged, and the degree of freedom in designing the optical circuit component is further increased.

Furthermore, the optical circuit component of the present invention may have a heat sink connected to at least a part of the heat radiating portion of the radiator. As a result, the heat radiation efficiency of the radiator can be further increased.

Further, it is preferable that the core and the clad layer are made of a glass material containing quartz, and the substrate is made of a glass material containing quartz or silicon. As a result, it is possible to realize an optical circuit component having a small propagation loss and excellent stability.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. First, a first embodiment of the present invention will be described. 1A is a plan view showing an optical circuit component according to this embodiment, and FIG. 1B is a sectional view taken along line 1B-1B in FIG.

As shown in FIGS. 1 (a) and 1 (b), in the optical switch according to this embodiment, a clad layer 2 is provided on a substrate 1, and the clad layers 2 are parallel to each other. Two cores 3a and 3b extending in the direction are formed. The substrate 1 is formed of, for example, a semiconductor such as silicon or InP or an insulating material such as quartz glass,
For example, it is formed of a silicon substrate having a thickness of 0.8 mm. The clad layer 2 and the cores 3a and 3b are formed of a semiconductor, glass, or the like, for example, quartz glass. The clad layer 2 includes a lower clad layer 2 a formed on the substrate 1 and the lower clad layer 2 a.
The upper clad layer 2b is formed on a. The lower clad layer 2a has a thickness of, for example, 15 μm, and the upper clad layer 2b has a thickness of, for example, 10 μm. Therefore, the total thickness of the clad layer 2 is, for example, 25 μm.
Is. The cores 3a and 3b are formed separately from each other in a direction parallel to the surface of the cladding layer 2 so as to be embedded in the lower portion of the upper cladding layer 2b.
The distance from b is, for example, 60 to 100 μm. The thickness of the cores 3a and 3b is, for example, 5 μm, and the width thereof is, for example, 5 μm. The clad layer 2 has a smaller refractive index than the cores 3a and 3b, and the relative refractive index difference Δ between them is Δ.
Is 0.65%. Clad layer 2 and core 3a
1 constitutes an optical waveguide, and the clad layer 2 and the core 3b constitute another optical waveguide. This optical waveguide is for transmitting light.

Thin film heaters 5a and 5b made of Cr, for example, are formed on the surface of the cladding layer 2 in the region including the region directly above the core 3a and the region including the region directly above the core 3b. The thin film heaters 5a and 5b are the cores 3a and 3
It has a rectangular shape extending parallel to the direction in which b extends,
The thickness is, for example, 0.2 μm, and the width is, for example, 20 μm.
m, and the length is 4 mm, for example. Heater power supply electrodes 6a and 6b are formed on the surface of the clad layer 2 and are connected to one ends of the thin film heaters 5a and 5b in the length direction, respectively. This heater power supply electrode 6
a and 6b are connected to the heater electrode terminals 7a and 7b, respectively, by bonding or the like, and are connected to an external power source (not shown) via the heater electrode terminals 7a and 7b.
The thin film heaters 5 a and 5 b heat the cores 3 a and 3 b via the cladding layer 2, respectively. The heater power supply electrodes 6a and 6b are formed of a material having an electric resistance value smaller than that of the thin film heaters 5a and 5b. For example, the thickness is 0.5 μm on a Ti film having a thickness of 0.1 μm.
The Au film is formed of a two-layer film. In this case, since the Au film has a smaller electric resistance value than the Cr film, power loss due to the heater power supply electrodes 6a and 6b can be suppressed. The Ti film functions as an adhesive layer between the Au film and the cladding layer 2. Also, the heater electrode terminal 7a
And 7b are made of metal wires, for example.

A radiator 8 is formed on the surface of the cladding layer 2. The radiator 8 is a thin film formed of a material having high thermal conductivity, and is formed of, for example, a (Ti / Au) two-layer film like the heater power supply electrodes 6a and 6b. The shape of the radiator 8 is a comb shape surrounding the thin film heaters 5a and 5b, and a part of the radiator 8 is formed in the area 9 immediately above the area between the cores 3a and 3b. The radiator 8 absorbs heat generated by the thin film heaters 5a and 5b and radiates the heat to the outside. The vicinity of the thin film heaters 5a and 5b is a heat absorbing portion, and the other portions are heat radiating portions. .

The ends of the thin film heaters 5a and 5b on the side not connected to the heater power supply electrodes 6a and 6b, respectively, are connected to a radiator 8, which is connected to a heater electrode terminal 7c. ing. The heater electrode terminal 7c is connected to a ground electrode (not shown). That is, the radiator 8 also serves as a heater power supply electrode for the thin film heaters 5a and 5b. Clad layer 2, core 3
a, heater 5a, heater power supply electrode 6a, radiator 8 as heater power supply electrode, and heater electrode terminal 7a
And 7c form one thermo-optical phase shifter, and the cladding layer 2, the core 3b, the heater 5b, the heater power supply electrode 6b, the radiator 8 as the heater power supply electrode, and the heater electrode terminals 7b and 7c. , Another thermo-optical phase shifter is formed.

Next, a method of manufacturing the optical circuit component according to this embodiment will be described. First, a silicon substrate having a thickness of 0.8 mm, for example, is prepared as the substrate 1. Next, a glass film containing quartz as a main component is formed on the substrate 1 by atmospheric pressure chemical vapor deposition (AP-CVD) to a thickness of, for example, 15 μm.
The lower clad layer 2a is formed to a film thickness of m. Next, similarly, the thickness is, for example, 5 by the AP-CVD method.
A glass film having a thickness of μm is formed, and the glass film is subjected to photolithography and reactive ion etching (RIE: Reactivi).
patterning by ty ion etching) to form rectangular cores 3a and 3b whose cross-sectional shape is, for example, 5 μm thick and 5 μm wide. At this time, the amount of impurities mixed in the lower clad layer 2a and the cores 3a and 3b is controlled so that the relative refractive index difference Δ between the lower clad layer 2a and the cores 3a and 3b becomes, for example, 0.65%. To
After that, AP-C is embedded so that the cores 3a and 3b are embedded.
According to the VD method, the film thickness on the lower clad layer 2a is, for example, 1
The upper clad layer 2b of 0 μm is formed. This allows
An embedded waveguide is manufactured.

Next, a Cr film having a film thickness of, for example, 0.2 μm is formed on the cladding layer 2 by electron beam evaporation, and the Cr film is photolithographically and wet etched to have a width of, for example, 20 μm and a length. Is patterned into, for example, a rectangular shape of 4 mm to form thin film heaters 5a and 5b. At this time, the thin film heater 5a is formed in a region including a region directly above the core 3a, and the thin film heater 5b is formed in a region including a region directly above the core 3b. Also, two layers of Ti and Au are continuously formed on the clad layer 2 by an electron beam evaporation method, and a Ti film having a thickness of, for example, 0.1 μm and an Au film having a thickness of, for example, 0.5 μm are formed. Form a film. Then, the two-layer film is patterned by photolithography and wet etching to form the heater power supply electrodes 6a and 6b and the radiator 8. At this time, a part of the radiator 8 is formed in the region 9 immediately above the region between the cores 3a and 3b. Then, the heater power supply electrodes 6a and 6b
The heater electrode terminals 7a, 7b and 7c are formed by bonding metal wires to the radiator 8 respectively. The heater electrode terminals 7a and 7b are connected to an external power source, and the heater electrode terminal 7c is connected to a ground electrode.

Next, the operation of the optical circuit component according to this embodiment will be described. An external power source (not shown) applies power to the thin film heater 5a or 5b via the heater electrode terminals 7a, 7b and 7c and the heater power supply electrodes 6a and 6b. As a result, the heater 5a or 5b generates heat by resistance heating to raise the temperature of the cladding layer 2 and the core 3a or 3b. As a result, the cladding layer 2 and the core 3a or 3
By changing the refractive index of the material forming b to control the effective length of the optical waveguide, the phase at the output end of the light incident on each waveguide is changed.

At this time, the heater 5 in the radiator 8
The portions located near a and 5b function as heat absorbing portions, and the other portions function as heat radiating portions. The heat generated by the heaters 5a and 5b is absorbed by the heat absorbing portion, a portion of which is radiated to the outside, and the remaining portion is conducted to the heat radiating portion. Heat is conducted from the heat absorbing portion to the heat radiating portion and radiates this heat to the outside. If the heat is radiated to the outside in the portions located in the vicinity of the heaters 5a and 5b to sufficiently perform the function as the radiator, the other portions may not be provided.

In the optical circuit component according to this embodiment, the thin film heater 5a is formed in the region including the region directly above the core 3a, and the thin film heater 5b is formed in the region including the region directly above the core 3b. The heat generated by the heaters 5a and 5b can be suppressed from being transferred to the substrate 1, and the cores 3a and 3b can be efficiently heated, respectively.

The heat generated by the thin film heater 5a is absorbed by the portion of the radiator 8 located between the cores 3a and 3b, so that the heat is transferred to the core 3a but is transferred to the core 3b. Is hardly transmitted. Similarly, the heat generated from the thin film heater 5b is absorbed by the portion of the radiator 8 and thus transferred to the core 3b.
Is hardly transmitted to. As a result, the thin film heater 5a
Efficiently controls the refractive index of the core 3a immediately below,
The thin film heater 5b can efficiently control the refractive index of the core 3b immediately below it. That is, good thermal isolation can be realized between the core 3a and the core 3b. Further, since the heat generated from the thin film heaters 5a and 5b is absorbed by the radiator 8, it is possible to prevent the heat from leaking to the outside of the optical circuit component. Similarly, the heat flowing from the outside is also absorbed by the radiator, so that the heat can be suppressed from being conducted to the cores 3a and 3b.

Therefore, in the optical circuit component of this embodiment, the distance between the optical waveguides can be reduced, and the size can be reduced. Also, when performing integration such as forming a plurality of the optical circuit components on the same substrate to form an array,
It is possible to achieve thermal isolation between the optical circuit components and other optical waveguides and the like existing around the optical circuit components, so that the device can be downsized and highly integrated. The optical circuit component according to the present embodiment is a Mach-Zehnder interferometer or AWG (Array Wave-guide Grating:
Array waveguide grating type multiplexing / demultiplexing circuit) and the like.

Further, in the optical circuit component of this embodiment,
The heater power supply electrodes 6a and 6b and the radiator 8 are
Since the thin film heaters 5a and 5b are made of Cr having a higher electric resistivity than Au, the thin film heater 5a includes a film made of Au having the lowest electric resistivity among all substances.
And 5b have good heating efficiency. Further, since the Ti film is provided between the Au film and the cladding layer 2 in the heater power supply electrodes 6a and 6b and the radiator 8, the Au film is provided.
The adhesion between the film and the clad layer 2 is good. Furthermore, since the Au film has high thermal conductivity, the radiator 8 has high heat absorption / heat radiation efficiency.

Further, in the optical circuit component of this embodiment,
Since the radiator 8 is formed by depositing a metal thin film by the electron beam evaporation method and patterning this metal thin film by photolithography and wet etching, it is easy to manufacture. Further, since the radiator 8 is formed at the same time as the heater power supply electrodes 6a and 6b,
There is almost no increase in the formation cost of the optical circuit component due to the formation of the radiator 8. Furthermore, since the optical waveguide of the optical circuit component of the present embodiment is a buried type in which the core is embedded in the cladding layer, the characteristics of the cladding layer arranged around the core can be made uniform. Therefore, the polarization dependence of the transmitted light is small.

In the present invention, the position of the radiator is not limited to the position of this embodiment, and it is provided above the entrance and exit ends of the cores 3a and 3b in order to realize a smaller device. Good. Further, in the present embodiment, the heater power feeding electrodes 6a and 6b and the radiator 8 are formed at the same time, but the present invention is not limited to this, and the heater power feeding electrode and the radiator may be separately manufactured. At this time, similarly to the present embodiment, the radiator may also serve as the heater power supply electrode. Furthermore, the heater power supply electrode and the radiator do not necessarily have to be formed of a (Ti / Au) two-layer film, and may be, for example, a single-layer film made of Cu or Al. Furthermore, the thin film heater can be formed of a metal other than Cr or a nonmetal. Furthermore, depending on the use of this optical circuit component, three or more cores may be formed and three or more optical waveguides may be provided.

Next, a second embodiment of the present invention will be described. FIG. 2 is a plan view showing the optical circuit component according to this embodiment. This embodiment is an example in which the optical circuit component according to the first embodiment is applied to a Mach-Zehnder interferometer. As shown in FIG. 2, in the optical circuit component of this embodiment, the couplers 4a are provided at the input and output ends of the cores 3a and 3b, respectively.
And 4b are provided, the input ends of the cores 3a and 3b are coupled by the coupler 4a, and the output ends of the cores 3a and 3b are coupled by the coupler 4b. As a result, the Mach-Zehnder interferometer 13 is formed.
The configuration of the Mach-Zehnder interferometer 13 other than the above is the same as the configuration of the optical circuit component according to the first embodiment described above.

In this embodiment, the core 3a or 3b can be heated by the thin film heater 5a or 5b generating heat. As a result, the refractive index of the core 3a and the refractive index of the core 3b can be made different from each other, and the phases of the lights transmitted through the cores 3a and 3b can be made different from each other in the coupler 4b. This allows the lights to interfere with each other. As a result, the intensity of the light output from the coupler 4b can be arbitrarily controlled within the range of 0 to 100% with respect to the intensity of the light input to the coupler 4a. Thereby, for example, VO
An element such as A for adjusting the intensity of output light can be formed. Further, for example, the phase difference between the lights transmitted through the cores 3a and 3b is set to 0, and the two are strengthened to each other, so that the same light as the light input to the coupler 4a can be obtained.
It can be output from b. Also, the phase difference between the two is π
The output of the coupler 4b can be set to 0 by setting (180 °) and canceling each other.
Thereby, an optical switch can be realized. The effects other than the above in this embodiment are the same as the effects of the first embodiment described above.

Next, a third embodiment of the present invention will be described. FIG. 3A is a plan view showing the configuration of the optical circuit component according to the present embodiment, and FIG. 3B is a sectional view taken along line 3B-3B in FIG. The optical circuit component of this example is characterized in that a groove is formed in the cladding layer. As shown in FIGS. 3A and 3B, in the optical circuit component of this embodiment, a part of the cladding layer 12 is removed in regions other than the regions directly above and immediately below the cores 3a and 3b, and the groove 30a is formed. And 30b and a removed portion 31 are formed. In the clad layer 12, the groove 30a is provided with the core 3b when viewed from the core 3a.
The groove 30b is formed in the region opposite to the core 3a.
Formed in a region between the core and the core 3b, and the removed portion 3
1 is formed on the opposite side of the core 3a when viewed from the core 3b. Then, the grooves 30a and 30b and the removed portion 3
A radiator 38 is formed at the bottom of the radiator 1. The configuration other than the above in the optical circuit component of the present embodiment is the same as in the first embodiment described above.
The configuration is the same as that of the optical circuit component according to the embodiment. In addition,
A Mach-Zehnder interferometer can be constructed by using the optical circuit component of the present embodiment as in the second embodiment.

The optical circuit component according to this embodiment is the same as the above-mentioned first component.
Similarly to the second embodiment, the waveguide structure including the cores 3a and 3b and the cladding layer 2 is formed, and the thin film heaters 5a and 5b and the heater power supply electrodes 6a, 6b and 6 are formed.
After forming c, by partially removing the regions on both sides of the regions directly above and immediately below the cores 3a and 3b in the cladding layer 2 by photolithography and RIE,
It can be easily manufactured. By removing the clad layer by RIE, which is a type of dry etching, the verticality of the etching end face can be secured, and particularly when a deep groove is formed in a narrow region having a width of several μm to several tens of μm. It is advantageous. In the etching, RI
A similar structure can be formed by combining ICP or wet etching other than E.

In this embodiment, the grooves 30a and 30b and the removed portion 31 are provided between and around the cores 3a and 3b.
Since it is possible to prevent the direct heat conduction between the cores 3a and 3b and the heat conduction between the outside by providing the above, it is particularly preferable to interpose the lower clad layer or the substrate. An effective method when heat conduction becomes a problem, for example, when the lower clad layer is thick and it is difficult to etch the substrate, and when the substrate is formed of a material having low heat conduction such as quartz glass. Is. Further, in this embodiment, not only can reliable thermal isolation between the waveguides be realized, but also the stress applied to the cladding layer can be released due to the difference in the thermal expansion coefficient between the substrate and the cladding layer. Therefore, it is possible to reduce the polarization dependence on the transmission of light.

Next, a fourth embodiment of the present invention will be described. FIG. 4 is a perspective view showing an optical circuit component according to this embodiment. The present embodiment is an example of an optical circuit component which is arranged near the device and has one optical waveguide. The device includes an integrated circuit, a laser oscillator, an AWG, and the like, as well as an optical waveguide. As shown in FIG. 4, in the optical circuit component of this embodiment, a substrate 1 made of, for example, silicon is provided, and a clad layer 2 made of, for example, quartz glass is provided on the substrate 1. Inside the clad layer 2, one core 3 extending in one direction is provided. The core 3 is made of, for example, quartz glass, the refractive index of the core 3 is larger than that of the cladding layer 2, and the relative refractive index difference Δ between the two is, for example, 0.65%. An optical waveguide is formed by the clad layer 2 and the core 3.

A thin film heater 5 made of, for example, Cr is provided on the upper surface of the clad layer 2 immediately above the core 3. The thin film heater 5 has a thickness of, for example, 0.2 μm, a width of, for example, 20 μm, and a length of, for example, 4 mm, and extends in the extending direction of the core 3. Further, radiators 8 are provided on both sides of the thin film heater 5 on the upper surface of the clad layer 2. Further, heater power supply electrodes 6a and 6b are provided at both ends of the thin film heater 5 in the longitudinal direction, and heater electrode terminals 7 are connected to the heater power supply electrodes 6a and 6b, respectively. The heater electrode terminal 7 is connected to an external power source (not shown). The radiator 8 is connected to the heater power supply electrode 6b, but is not connected to the heater power supply electrode 6a. Therefore, the heat absorbed by the radiator 8 is radiated to the outside of the optical circuit component via the heater power supply electrode 6b, but the current supplied to the heater power supply electrodes 6a and 6b does not flow through the radiator 8 and is entirely thin film. Heater 5
It is designed to flow through. The configuration of the optical circuit component of this example other than the above is the same as the configuration of the optical circuit component according to the first example described above.

In the optical circuit component according to this embodiment, since the thin film heater 5 is formed immediately above the core 3, it is possible to suppress the heat generated by the thin film heater 5 from being transferred to the substrate 1 and to prevent the core 3 from being transferred. It can be heated efficiently. Further, since the heat generated by the thin film heater 5 is absorbed by the radiator 8, it is efficiently transmitted to the core 3, but the leakage of this optical circuit component to the outside is suppressed. Further, the heat transmitted from the outside is absorbed by the radiator 8 and is hardly transmitted to the core 3. As a result, good thermal isolation can be realized between the core 3 and the outside. As a result, heat separation between the present optical circuit component and the adjacent device can be achieved, and the device in which the optical circuit component is mounted can be downsized and highly integrated. The effects of this embodiment other than the above are the same as the effects of the first embodiment described above. Further, in this embodiment, as shown in the third embodiment, grooves may be formed in the regions on both sides of the core 3 in the cladding layer 2.

Next, a fifth embodiment of the present invention will be described. FIG. 5 is a sectional view showing an optical circuit component according to this embodiment. In this embodiment, the optical circuit component according to the fourth embodiment is an LSI for controlling a thin film heater as a device.
(Large scale integrated circuit)
This is an example of arrangement in the vicinity of. As shown in FIG. 5, in this embodiment, the chip 14 having the LSI 14a formed on the surface thereof is mounted on the cladding layer 2 of the optical circuit component according to the fourth embodiment. The LSI 14a controls the thin film heater 5. A radiator 8 is provided between the chip 14 and the thin film heater 5 on the surface of the clad layer 2.

In this embodiment, since the heat generated from the thin film heater 5 is absorbed by the radiator 8, it is possible to prevent the heat from being conducted to the LSI 14a and affecting the operation of the LSI 14a. Further, since the heat generated from the LSI 14a is absorbed by the radiator 8, it is possible to prevent the heat from being conducted to the core 3 and affecting the phase of the light transmitted through the core 3. The effects of the present embodiment other than the above are the same as the effects of the above-described fourth embodiment.

In this embodiment, the cladding layer 2
A groove may be provided between the chip 14 and the radiator 8 in FIG. As a result, the heat separation between the thin film heater 5 and the chip 14 can be further improved.

Next, a sixth embodiment of the present invention will be described. FIG. 6 is a sectional view showing an optical circuit component according to this embodiment. This embodiment is an example in which a laser oscillator 15 is provided instead of the chip 14 in the fifth embodiment.
As shown in FIG. 6, a laser oscillator 15 is formed on the cladding layer 2.
Is mounted, and the optical circuit component according to the present embodiment is arranged in the vicinity of the laser oscillator 15. In this optical circuit component, a radiator 8 is provided between the laser oscillator 15 on the surface of the clad layer 2 and the thin film heater 5, and the laser oscillator 15 in the clad layer 2 and the radiator near the laser oscillator 15 are provided. A groove 30c is provided between the groove 8 and the groove 8.

In the present embodiment, since the heat generated from the laser oscillator 15 is absorbed by the radiator 8,
This heat can be prevented from being conducted to the core 3 and affecting the phase of light transmitted through the core 3. Further, since the heat generated from the thin film heater 5 is absorbed by the radiator 8, it is possible to prevent the heat from being conducted to the laser oscillator 15 and affecting the operation of the laser oscillator 1. Also, the clad layer 2
Since the groove 30c is provided in the laser, the thermal isolation between the thin film heater 5 and the core 3 and the laser oscillator 15 can be further improved. Effects other than the above according to the present embodiment,
The effect is the same as that of the above-described fourth embodiment.

Next explained is the seventh embodiment of the invention. 7A is a plan view showing the configuration of the optical circuit component according to the present embodiment, and FIG. 7B is a sectional view taken along line 7B-7B in FIG. 7A. The optical circuit component of this example is characterized in that it has one core and has a slab shape.

As shown in FIGS. 7A and 7B, in the optical circuit component of this embodiment, the cladding layer 2 is formed on the substrate 1.
Is provided, and one slab-shaped core 13 is provided in the cladding layer 2. The thickness of the core 13 is, for example, 5 μm, and the width thereof is, for example, 250 μm. An optical waveguide is constituted by the core 13 and the clad layer 2. Further, thin film heaters 5a and 5b are provided separately from each other in the region directly above the core 13 on the surface of the clad layer 2. The configuration of the optical circuit component of this example other than the above is the same as the configuration of the optical circuit component according to the first example described above.

In an element in which a plurality of waveguides such as optical couplers are connected to a waveguide whose core shape is a slab (hereinafter referred to as slab waveguide), the inside of the slab waveguide is used for the purpose of downsizing the element. You may want to adjust the phase of light with. For example, there is a case where the incident light is frequency-separated by an arrayed-waveguide grating type multiplexer / demultiplexer circuit (AWG) or the like, and the phase of each frequency component of the separated light is individually adjusted in the slab waveguide. In such a case, an optical circuit component in which a heater array including the thin film heaters 5a and 5b is formed on the slab-shaped core 13 as shown in FIGS. 7A and 7B is effective. In the optical circuit component of this embodiment, the core 13 can be unevenly heated in the width direction by applying arbitrary power to the thin film heaters 5a and 5b, and the core 13 can be heated in the width direction. It is possible to form a non-uniform refractive index distribution.

At this time, in order to make the width of the slab waveguide as small as possible, it is necessary to narrow the gap between the thin film heaters 5a and 5b, and heat isolation from adjacent thin film heaters causes thermal isolation. It deteriorates, and it becomes difficult to adjust the individual refractive index change amount. This point is the same as that described in the first to sixth embodiments. In the present embodiment, the thin film heaters 5a and 5b are provided in a part of the region directly above the core 13 on the surface of the cladding layer 2, and one of the regions other than the region where the thin film heaters 5a and 5b are provided. A radiator 8 is provided in the section. This can improve the thermal isolation.

The radiator may be formed inside the cladding layer. For example, when a radiator is provided below the core 13, first, the radiator is formed inside the lower clad layer, and then, after the core 13 and the upper clad layer are formed, a radiator is formed on the radiator by dry etching (RIE). The cladding layer 2 in the region corresponding to is etched and selectively removed. Further, by disposing the radiator both on the surface of the upper clad layer and inside the lower clad layer, thermal isolation can be further ensured. Further, although two thin film heaters are formed in the present embodiment, one or three or more thin film heaters may be formed if necessary.

Next, an eighth embodiment of the present invention will be described. FIG. 8 is a sectional view showing the optical circuit component according to the present embodiment. In the optical circuit component of this embodiment, the thin film heater 5a is formed by the divided heaters 16a and 16b, and the thin film heater 5b is formed by the divided heaters 16c and 16d as compared with the optical circuit component according to the first embodiment. It is characterized in that it is done. The thin film heaters 5a and 5b are formed in regions including the regions directly above the cores 3a and 3b, respectively. The divided heaters 16a and 16b are provided in parallel to each other, and the divided heaters 16a and 16b are formed on both sides of the region directly above the core 3a, and in regions deviated from this region directly above. Similarly,
The divided heaters 16c and 16d are provided in parallel with each other, and the divided heaters 16c and 16d are formed on both sides of the region directly above the core 3b, and in regions deviated from this region directly above.
That is, the thin film heaters 5a and 5b are formed in the regions including the regions directly above the cores 3a and 3b, respectively, but the divided heaters are formed in the regions including the regions directly above the cores 3a and 3b, respectively. Absent. The configuration and effects of this embodiment other than the above are the same as those of the first embodiment described above.

Next, a ninth embodiment of the present invention will be described. FIG. 9 is a sectional view showing an optical circuit component according to this embodiment. The optical circuit component of the present embodiment is characterized in that the thin film heaters 5a and 5b are provided in the cladding layer 2 as compared with the optical circuit component according to the first embodiment described above. Figure 9
As shown in FIG. 5, in the optical circuit component of this embodiment, the thin film heaters 5a and 5b are provided above the cores 3a and 3b in the cladding layer 2, respectively. The configuration of the optical circuit component of this example other than the above is the same as the configuration of the optical circuit component according to the first example described above.

In the optical circuit component of this embodiment, the thin film heaters 5a and 5b are provided closer to the cores 3a and 3b, respectively, as compared with the first embodiment described above.
The cores 3a and 3b can be heated more efficiently. The effects of this embodiment other than the above are the same as those of the above-described first embodiment. The optical circuit component of this embodiment can also be applied to the Mach-Zehnder interferometer as shown in the second embodiment. Further, a groove may be provided in a region where the core is not formed in the clad layer 2, and an LSI or a laser oscillator may be mounted on the clad layer 2. Further, the technique of providing the thin film heater in the clad layer shown in the present embodiment can be applied to the optical circuit component having the slab core shown in the seventh embodiment.

Next, a tenth embodiment of the present invention will be described. FIG. 10A is a plan view showing the configuration of the optical circuit component according to the present embodiment, and FIG. 10B is a 10B-10 of FIG.
It is sectional drawing by the B line. The optical circuit component of the present embodiment is characterized in that the heat absorbing portion of the radiator 18 is embedded in the clad layer 22 as compared with the optical circuit component according to the first embodiment described above.

As shown in FIGS. 10A and 10B, the radiator 18 is composed of a heat absorbing portion 18a embedded in the clad layer 22 and a heat radiating portion 18b exposed to the outside of the clad layer 22. The heat absorbing portion 18a is formed in the clad layer 22 in a region other than the regions directly above and below the cores 3a and 3b, and is also formed in the region between the cores 3a and 3b. In this embodiment, the heat absorbing portion 18a is arranged at a position lower than the cores 3a and 3b. Further, the heat radiating portion 18b of the radiator 18 is arranged at the same height as the heat absorbing portion 18a.
There is no clad layer on b. Heat dissipation part 18b
The upper clad layer is once formed and then removed by dry etching or wet etching. Therefore, the surface of the heat dissipation portion 18b is exposed to the outside of the cladding layer 22. The configuration of the optical circuit component of this example other than the above is the same as the configuration of the optical circuit component according to the first example described above.

Next, a method of manufacturing the optical circuit component according to this embodiment will be described. For example, a case where the heat absorbing portion 18a of the radiator 18 is located 5 μm below the cores 3a and 3b and is located at an intermediate position between the cores 3a and 3b will be described. First, a first lower clad layer having a film thickness of 10 μm is formed on the substrate 1 by the AP-CVD method, and then a metal film made of, for example, Cr and having a thickness of 0.5 μm is formed by the electron beam evaporation method. To form a film. This metal film is processed into a desired pattern by photolithography and wet etching to form the radiator 18. After that, a second lower clad layer having a film thickness of 5 μm is further formed on the entire surface by AP-CVD. As a result, the lower cladding layer in which the patterned radiator 18 is embedded is formed. Then, similarly to the first embodiment, the cores 3a and 3b are formed and the upper clad layer is formed. Next, the clad layer on the heat radiating portion 18b of the radiator 18 is removed by RIE to expose the heat radiating portion 18b.

In this embodiment, the heaters 5a and 5b are used.
Since the radiator 18 and the radiator 18 can be separated from each other, it is possible to prevent the heat generated from the thin film heaters 5a and 5b from directly flowing into the radiator 18. For this reason,
The heating efficiency of the cores 3a and 3b is improved, and the power consumption can be reduced. Further, since the heat dissipation portion 18b is exposed to the outside of the cladding layer 12, the heat dissipation efficiency is high. Further, since the optical circuit component has the embedded structure, the radiator can be three-dimensionally arranged without being restricted by the position of the core, and thus the degree of freedom in designing the optical circuit component is improved. As a result, a better thermal isolation design is possible.
Further, in the optical circuit component according to the present embodiment, it is possible to suppress the sneak of heat from the lower clad layer, as compared with the first embodiment described above.

It is possible to provide both the radiator formed on the cladding layer shown in the first embodiment and the radiator formed in the cladding layer shown in this embodiment. Thereby, the heat transfer to the adjacent optical waveguide can be suppressed sufficiently low, and the thermal isolation can be further ensured.

The optical circuit component of this embodiment can be applied to a Mach-Zehnder interferometer as in the second embodiment. A device such as an LSI or a laser oscillator may be mounted on the clad layer 22. Furthermore,
The technique of forming the radiator shown in this embodiment from the heat absorbing portion and the heat radiating portion and forming the heat absorbing portion in the clad layer can be applied to each of the first to ninth embodiments.

Next, an eleventh embodiment of the present invention will be described. 11A is a plan view showing the configuration of the optical circuit component according to the present embodiment, and FIG. 11B is a plan view of 11B-11 of FIG. 11A.
It is sectional drawing by the B line. In the optical circuit component of this embodiment, the heat absorbing portion of the radiator is embedded in the clad layer, the heat radiating portion of the radiator is formed on the clad layer, and the heat absorbing portion and the heat radiating portion are thermally connected by vias. It is characterized in that it is done.

As shown in FIGS. 11A and 11B, in the optical circuit component of this embodiment, the cores 3a and 3b are formed in the clad layer 32, and the cores 3a and 3b in the clad layer 32 are formed. The heat absorbing portion 28a of the radiator 28 is formed in a region other than the region directly above and directly below 3b.
In this embodiment, the heat absorbing portion 28a is formed at the same height as the cores 3a and 3b. Further, a heat radiation portion 28b of the radiator 28 is formed on the cladding layer 32, and the heat absorption portion 28a and the heat radiation portion 28b are thermally connected by the via 11. The configuration of the optical circuit component of this example other than the above is the same as the configuration of the optical circuit component according to the first example described above.

In this embodiment, as in the tenth embodiment described above, a waveguide structure is manufactured in which the heat absorbing portion 28a of the radiator 28 is embedded in the cladding layer 32, and RI is formed.
A via hole is formed by removing a part of the clad layer immediately above the heat absorbing portion 28a by etching with E or the like, and a material having a high thermal conductivity such as metal is embedded in the via hole to form the via 11. Then, the heat dissipation portion 28b of the radiator 28 is formed on the surface of the clad layer 22. As a result, the heat absorbing portion 28a and the heat radiating portion 2 of the radiator 28 are
Since 8b can be arranged at any position, the degree of freedom in designing the optical circuit component is further improved. The effects of this embodiment other than the above are the same as those of the first embodiment described above.

As in the tenth embodiment described above, the heat radiation portion of the radiator is arranged below the core, and this heat radiation portion is thermally connected to the heat absorbing portion via the via so that the heat radiation portion above the radiator is located above. The clad layer may be removed to expose this heat dissipation portion. Further, the optical circuit component of the present embodiment,
It can be applied to a Mach-Zehnder interferometer as in the second embodiment. Further, a device such as an LSI or a laser oscillator may be mounted on the clad layer 32.

Next, a twelfth embodiment of the present invention will be described. FIG. 12A is a plan view showing an optical circuit component according to this embodiment, and FIG. 12B is a sectional view taken along line 12B-12B in FIG. The optical circuit component of this embodiment is characterized in that the heat sink 10 is attached to the radiator of the radiator, as compared with the optical circuit component according to the first embodiment. A wide variety of commonly used products can be used for the heat sink. For example, it may be a simple and easy-to-use one manufactured by cutting out from an aluminum block, a fan provided with a blower fan, or a Peltier element. The amount of heat radiation can be easily controlled by controlling the size of the heat sink, the amount of air blown by the blower fan, the amount of current flowing to the Peltier element, and the like. The configuration of the optical circuit component of this example other than the above is the same as the configuration of the optical circuit component according to the first example described above.

When the distance between the thermo-optical phase shifters is narrowed as the optical circuit components are highly integrated, the thermal interference from the heaters of the adjacent thermo-optical phase shifters becomes large. At this time, by setting the heat absorption amount of the radiator to an optimum value, it becomes possible to control the temperature distribution in the optical circuit component, and an optimum heat separation design can be realized. It may be necessary to increase the amount of heat absorption in order to obtain the desired heat distribution, and in some cases a forcible heat release means such as a heat sink may be required to ensure a heat separation design.
In this embodiment, by providing the heat sink 10, the amount of heat absorbed by the radiator 8 can be increased, and the heat separation of the optical circuit component can be performed more reliably. Further, if a heat sink having a blower fan or a heat sink composed of a Peltier element is used, the heat absorption amount of the radiator can be controlled arbitrarily.

In this embodiment, the basic structure of the optical circuit component is the same as that of the optical circuit component according to the first embodiment, and the heat sink is arranged on the radiator formed on the surface of the upper clad layer. However, the present invention is not limited to this. For example, the technique of attaching a heat sink to the heat radiation portion of the radiator shown in this embodiment may be applied to each of the second to eleventh embodiments described above. Also in this case, the same effect as that of the present embodiment can be obtained, and the highly integrated and miniaturized design of the optical circuit component can be surely performed. However, the heat sink may be omitted if sufficient heat can be released only by the radiator.

In the above-mentioned first to twelfth embodiments, the buried type waveguide has been described, but the waveguide structure provided in the optical circuit component of the present invention is not limited to this, for example, a ridge type waveguide. May be arranged in plural, and in this case, the same effect as that of each of the above-described embodiments can be obtained. Further, the shape of the thin film heater is not limited to the rectangular shape, and may be any shape as long as the core of the waveguide can be heated to a desired temperature and the refractive index change can be induced.

[0081]

The effects of the present invention will be specifically described below in comparison with comparative examples that depart from the scope of the claims.
In optical circuit components, a thin-film heater is provided in the area including the area directly above the core, and a radiator is provided in an area outside the area directly above the core to reduce heat transfer to adjacent waveguides and reduce size. Whether or not it was possible was evaluated by performing a simulation by a finite element method (FEM).

FIG. 13 is a perspective view showing the thermo-optical phase shifter of the embodiment of the present invention in this simulation. As shown in FIG. 13, in the thermo-optic phase shifter according to the embodiment of the present invention, the cladding layer 2 is provided on the substrate 1,
The core 3 was provided in the clad layer 2. The core 3 has a rectangular parallelepiped shape, a thickness of 5 μm, and a width of 20 μm. The total thickness of the cladding layer 2 is 25 μm,
The film thickness above and below the core 3 was 10 μm. Further, a thin film heater 5 was provided in a region on the upper surface of the clad layer 2 just above the core 3, and the thin film heater 5 had a width of 20 μm, a length of 4 mm and a film thickness of 0.2 μm.
Further, two radiators 8 were provided on the upper surface of the clad layer 2 on both sides of the thin film heater 5 at a distance of 5 μm from the thin film heater 5, respectively. The width of this radiator 8 is 30μ
m, the length was 4 mm, and the heat absorption amount was 45 mW.
Furthermore, heater power supply electrodes 6a and 6b are provided on the clad layer 2 and are connected to both ends of the thin film heater 5, respectively. A heater electrode terminal 7 was connected to each of the heater power supply electrodes 6a and 6b.

On the other hand, FIG. 14 is a perspective view showing a thermo-optical phase shifter of a comparative example in this simulation. Figure 1
As shown in FIG. 4, in the thermo-optical phase shifter of this comparative example, the radiator 8 is removed from the thermo-optical phase shifter according to the embodiment of the present invention shown in FIG. The configuration of this thermo-optical phase shifter other than the above is the same as that of the thermo-optical phase shifter of the embodiment of the present invention shown in FIG.

In the thermo-optical phase shifter as described above,
A case of applying an electric power of 300 mW to the thin film heater 5 was simulated. FIG. 15 is a graph showing the cross-sectional temperature distribution in the thermo-optical phase shifter of the embodiment of the present invention shown in FIG. 13, where the horizontal axis represents the horizontal position of the thermo-optical phase shifter and the vertical axis represents the vertical position. It is a figure. In the horizontal and vertical positions, the center of the core is 0. Also, the curves in the figure show isotherms, the numbers in the figure show the absolute temperature of each isotherm, and the interval between each isotherm is 1K. A region 32 shown in FIG. 15 is a region having the same size as the core 3 and a center of X = 20 μm and Y = 0 μm, and the thin film heater 5 is formed in a region outside the region including the region directly above the core. The position of the core is shown virtually. Further, FIG. 16 shows the horizontal temperature distribution in the thermo-optical phase shifter of the present embodiment, in which the horizontal axis indicates the horizontal position and the vertical axis indicates the temperature at each position with respect to the temperature at the center of the core. It is a graph figure. The value y (dB) shown on the vertical axis in FIG. 16 is given by the following mathematical formula 1 when the temperature at the position X in the horizontal direction is T _{X = X} (K).

[0085]

[Equation 1]

Further, FIG. 17 is a graph showing a cross-sectional temperature distribution in the thermo-optical phase shifter of the comparative example, with the horizontal axis representing the horizontal position of the thermo-optical phase shifter and the vertical axis representing the vertical position. is there. The curves in the figure show the isotherms,
The numbers in the figure indicate the absolute temperature of each isotherm. Isotherm is 1K
Are shown for each. Further, in FIG. 18, the horizontal axis represents the horizontal position, and the vertical axis represents the temperature y at each position with respect to the temperature of the center of the core (see Formula 1), and the horizontal direction in the thermo-optical phase shifter of the comparative example is shown. It is a graph showing the temperature distribution of.

As shown in FIG. 16, in the thermo-optic phase shifter of the embodiment of the present invention, when the temperature at the core center is used as a reference, the position at a distance of 20 μm from the core center (region 32).
The thermal isolation at was -2 dB. Therefore, when the thin film heater is arranged in the region including the region directly above the core, the heating efficiency of the core is better than when the thin film heater is arranged in a region outside the region including the region directly above the core. It was Further, the thermal isolation at a position at a distance of 50 μm from the center of the core was −25 dB. On the other hand, as shown in FIG. 18, in the thermo-optical phase shifter of the comparative example, the distance from the core center is 300.
Thermal isolation at μm is -19d
B, and the thermal isolation at a position where the distance from the center of the core was 1 mm was -25 dB. Therefore, in the thermo-optical phase shifter having the radiator 8, at a position at a distance of 50 μm from the core center, thermal isolation corresponding to a position at a distance of 1 mm from the core center in the thermo-optical phase shifter having no radiator was obtained. . As described above, in the example of the present invention, the heat transfer in the direction (horizontal direction) from the thin film heater to the adjacent optical waveguide was obviously suppressed as compared with the comparative example, and the isolation was improved. . Therefore, in the thermo-optical phase shifter, if a thin film heater is provided in a region including a region directly above the core and a radiator is further provided, size reduction can be achieved while maintaining sufficient characteristics.

As shown in FIG. 18, there was a portion where the thermal isolation deteriorated in the vicinity of the position where the distance from the core center was 100 μm. It can be understood that this is because the thermal conductivity of the lower clad layer is low, so that the temperature of the clad layer rises as heat from the thin film heater circulates from the lower side.

Further, in order to confirm the effect of the radiator in the thermo-optical phase shifters according to the above-mentioned Examples and Comparative Examples, a Mach-Zehnder type optical interferometer using the above-mentioned thermo-optical phase shifter was manufactured, and You may compare the input electric energy which can obtain an extinction ratio. If a thin-film heater of the same length is formed above the waveguide core, the heat generated by the thin-film heater will flow to the adjacent waveguide when the amount of power that can heat the thin-film heater on one side to obtain the maximum extinction ratio is lower. It can be said that the transmission does not induce a change in the refractive index of the adjacent waveguide core, but thermal crosstalk with the adjacent waveguide is small. As a result of the experiment, the Mach-Zehnder type optical interferometer equipped with the radiator is
The maximum extinction ratio was obtained with less power than the Mach-Zehnder interferometer without a radiator.

[0090]

As described in detail above, according to the present invention,
In an optical circuit component such as a Mach-Zehnder interferometer or a thermo-optic shift array, by arranging a thin film heater in a region including a region directly above or below the core of an optical waveguide, and arranging a radiator in a region between cores, It is possible to improve the thermal isolation, prevent heat from interfering with each other inside the optical circuit component and outside the optical circuit component, and individually and independently adjust the phase of the waveguide. Further, since the radiator can be easily formed by a method generally used for large-scale electronic integrated circuits such as photolithography and wet etching or dry etching, without affecting the yield of optical circuit components, An optical circuit component having excellent optical characteristics can be manufactured. Therefore, according to the present invention, it is possible to achieve miniaturization, high functionality and large scale of the optical circuit component.

[Brief description of drawings]

1A is a plan view showing an optical circuit component according to a first embodiment of the present invention, and FIG. 1B is a sectional view taken along line 1B-1B in FIG.

FIG. 2 is a plan view showing an optical circuit component according to a second embodiment of the present invention.

3A is a plan view showing an optical circuit component according to a third embodiment of the present invention, and FIG. 3B is a sectional view taken along line 3B-3B in FIG.

FIG. 4 is a perspective view showing an optical circuit component according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing an optical circuit component according to a fifth embodiment of the present invention.

FIG. 6 is a sectional view showing an optical circuit component according to a sixth embodiment of the present invention.

7A is a plan view showing an optical circuit component according to a seventh embodiment of the present invention, and FIG. 7B is a sectional view taken along line 7B-7B in FIG. 7A.

FIG. 8 is a sectional view showing an optical circuit component according to an eighth embodiment of the present invention.

FIG. 9 is a sectional view showing an optical circuit component according to a ninth embodiment of the present invention.

FIG. 10A is a plan view showing an optical circuit component according to a tenth embodiment of the present invention, and FIG. 10B is a plan view of 10B- of FIG.
It is sectional drawing by the 10B line.

11A is a plan view showing an optical circuit component according to an eleventh embodiment of the present invention, and FIG. 11B is a plan view of 11B- of FIG. 11A.
It is sectional drawing by the 11B line.

12A is a plan view showing an optical circuit component according to a twelfth embodiment of the present invention, and FIG. 12B is a plan view of 12B- of FIG.
FIG. 12B is a sectional view taken along line 12B.

FIG. 13 is a perspective view showing a thermo-optical phase shifter according to an embodiment of the present invention.

FIG. 14 is a perspective view showing a thermo-optical phase shifter of a comparative example.

FIG. 15 is a graph showing a cross-sectional temperature distribution in the thermo-optical phase shifter of the example of the present invention, where the horizontal axis represents the horizontal position of the thermo-optical phase shifter and the vertical axis represents the vertical position. .

FIG. 16 is a graph showing a horizontal temperature distribution in the thermo-optical phase shifter of the present embodiment, where the horizontal axis represents the horizontal position and the vertical axis represents the temperature at each position with respect to the temperature of the core center. Is.

FIG. 17 is a graph showing a cross-sectional temperature distribution in a thermo-optical phase shifter of a comparative example, where the horizontal axis represents the horizontal position of the thermo-optical phase shifter and the vertical axis represents the vertical position.

FIG. 18 is a graph showing a horizontal temperature distribution in a thermo-optical phase shifter of a comparative example in which the horizontal axis represents the horizontal position and the vertical axis represents the temperature at each position with respect to the temperature of the center of the core. is there.

FIG. 19 is a perspective view showing a Mach-Zehnder interferometer using a conventional ridge waveguide.

[Explanation of symbols]

1; substrate 2, 12, 22, 32; clad layer 2a; lower clad layer 2b; upper clad layer 3, 3a, 3b, 13; core 4a, 4b; coupler 5, 5a, 5b; thin film heater 6a, 6b: heater power supply electrodes 7, 7a, 7b, 7c; heater electrode terminals 8, 18, 28, 38; radiator 9; area 10; Heat sink 11; Via 13; Mach-Zehnder interferometer 14; Chip 14a; LSI 15; Laser oscillator 16a, 16b, 16c, 16d; split heater 18a, 28a; endothermic portion 18b, 28b; heat dissipation portion 30a, 30b, 30c; groove 31; removed part 32; area 101; substrate 102; optical waveguide 103; input terminal 104; output terminal 105a, 105b; optical waveguide 106; heater 107; Metal film for heat dissipation

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H047 KA04 NA01 QA04 RA08 TA11                 2H079 AA06 AA12 BA01 BA03 CA05                       DA17 DA23 EA05 EB27

Claims (19)

[Claims] 1. A substrate, a clad layer provided on the substrate, and a plurality of optical waveguides which are provided in the clad layer and are spaced apart from each other in a direction parallel to the surface of the clad layer. A plurality of cores constituting the thin film heater, which is provided in a region including at least one region directly above or immediately below the core and changes the phase of light of the optical waveguide by generating heat; A radiator provided in a region directly above or below the region for absorbing heat emitted by the thin film heater. 2. The number of the cores is 2, and the input ends of the cores are coupled to each other and the output ends of the cores are coupled to each other. The described optical circuit component. 3. The phase of the light of the one optical waveguide and the phase of the light of the other optical waveguide are equal to each other, or 180
The optical circuit component according to claim 2, wherein whether to output light from the output end is selected by making the difference. 4. The optical circuit component according to claim 1, wherein a groove is formed in at least a part of a region between the cores in the clad layer. 5. An optical circuit component arranged adjacent to a device, a substrate, a clad layer provided on the substrate, and a core provided in the clad layer and forming an optical waveguide together with the clad layer. A thin film heater provided in a region including a region directly above or below the core to change the phase of light in the optical waveguide by generating heat, a region between the core and the device, or a region directly above the region or An optical circuit component, comprising: a radiator provided in a region directly below and a radiator that absorbs heat emitted from the thin film heater or the device. 6. The optical circuit component according to claim 5, wherein the device is an integrated circuit that controls the thin film heater. 7. The optical circuit component according to claim 5, wherein the device is a laser oscillator. 8. The optical circuit according to claim 5, wherein a groove is formed in at least a part of a region between the core and the device in the cladding layer. parts. 9. A substrate, a clad layer provided on the substrate, a slab-shaped core provided in the clad layer to form an optical waveguide together with the clad layer, and in a region directly above or directly below the core. A region between the thin film heater and one or a plurality of thin film heaters which are provided in a direction parallel to the surface of the clad layer and are spaced apart from each other to heat the core unevenly in the width direction, A radiator provided in a region directly above or below the region for absorbing heat emitted by the thin film heater. 10. The optical circuit component according to claim 1, wherein the thin film heater comprises a plurality of divided heaters. 11. The clad layer includes a lower clad layer formed on the substrate, and an upper clad layer formed so that a lower surface of the clad layer contacts an upper surface of the lower clad layer.
And the core is in contact with an interface between the lower clad layer and the upper clad layer.
The optical circuit component according to any one of items 1 to 10. 12. The optical circuit component according to claim 1, wherein the thin film heater is provided on the clad layer. 13. The optical circuit component according to claim 1, wherein the thin film heater is provided in the clad layer. 14. The radiator includes an endothermic portion that absorbs heat emitted by the thin film heater, and a heat radiating portion that is connected to the endothermic portion and radiates heat absorbed by the endothermic portion.
The optical circuit component according to any one of claims 1 to 13, further comprising: 15. The light according to claim 14, wherein a heat absorbing portion of the radiator is embedded in the clad layer, and a heat radiating portion of the radiator is exposed to the outside of the clad layer. Circuit parts. 16. The optical circuit component according to claim 15, further comprising a via formed inside the cladding layer to thermally connect the heat absorbing portion and the heat radiating portion of the radiator. 17. The optical circuit component according to claim 14, further comprising a heat sink connected to at least a part of a heat radiation portion of the radiator. 18. The optical circuit component according to claim 1, wherein the core and the clad layer are made of a glass material containing quartz. 19. The optical circuit component according to claim 1, wherein the substrate is made of a glass material containing quartz or silicon.