JP2018109700A - Optical waveguide component and manufacturing method thereof - Google Patents

Abstract

An optical waveguide component that realizes low-loss optical coupling with a surface-mounted optical element, and a method for manufacturing the same. An optical waveguide provided on a substrate and made up of a core, an underclad and an overclad, a port for inputting signal light to the core, and inclined with respect to the vertical direction of the substrate and deeper than the core. An optical path conversion port in which a mirror 110 with a reflecting film is formed at least in a region intersecting the exit direction of the core of the formed inclined surface, and an overcladding through which the beam whose optical path has been converted in the optical path conversion port passes An optical waveguide component including a convex lens 160 provided on the surface, and a partition layer 150 made of a material having a softening temperature higher than that of the material of the over cladding and the convex lens, between the over cladding 108 and the convex lens 160. . The convex lens is formed by annealing after forming the lens layer in the partition layer. [Selection] Figure 6

Description

  The present invention relates to an optical waveguide component and a method of manufacturing the same, and more particularly to an optical waveguide component applicable to an optical communication system, and has a reflection mirror structure used when mounting an optical element such as a photodiode or a laser diode. The present invention relates to an optical waveguide component and a manufacturing method thereof.

  In recent years, with the spread of optical fiber transmission, a technology for integrating a large number of optical functional elements at a high density has been demanded. As one of them, a quartz-based planar lightwave circuit (hereinafter referred to as PLC (Planar Lightwave Circuit)) is known. It has been. The PLC is a waveguide type optical device with excellent characteristics such as low loss, high reliability, and high design flexibility. Actually, the transmission equipment at the optical communication transmission end has functions such as multiplexer / demultiplexer, branch / coupler, etc. A PLC in which is integrated is mounted. In addition, optical devices other than PLC, such as photodiodes (hereinafter referred to as PD (Photodiode)) and laser diodes (LD (Laser diode)), which convert optical and electrical signals, are mounted in the transmission apparatus. Yes. For further expansion of communication capacity, there is a demand for a highly functional optoelectronic integrated device in which an optical waveguide such as a PLC that performs optical signal processing and an optical device such as a PD that performs photoelectric conversion are integrated. PLC is promising as a platform for such an integrated optical device, and an optoelectronic integrated device in which a PD chip and a PLC chip are integrated in a hybrid manner has been proposed (for example, see Patent Document 1). In the example of Patent Document 1, a 45-degree mirror is provided in a partial region of the waveguide, and a PD is mounted on the waveguide, whereby light propagating through the optical waveguide is vertically converted by the mirror, A method of performing optical coupling is employed. Such a device structure in which an optical path conversion mirror for optical coupling and an optical element such as a PD are mounted on a PLC is advantageous in terms of downsizing of the device and the degree of freedom in designing an optical circuit.

  Furthermore, in recent years, in order to integrate high-speed optical elements of several tens of GHz, lens integration on the PLC surface has been studied.

  As shown in FIG. 1, for example, when light is emitted from the PLC 100 by optical path conversion by the mirror 110, the beam is diffracted and spread when it is emitted from the waveguide. Therefore, in order to optically couple to the light receiving unit 202 with a small diameter included in the high-speed PD 200 with low loss, it is necessary to collect light by an optical coupling element such as a lens. Assuming that a beam is incident from the LD, the beam is expanded unless there is a lens. Therefore, it can be seen that in this case as well, high-efficiency optical coupling to the waveguide is difficult without a lens.

  However, when an optical coupling element such as a lens is separately mounted, an extra area for mounting is required in addition to the size of the member itself. Therefore, since the optical coupling portion is increased in size, it is required to manufacture the lens 160 directly on the PLC surface as shown in FIG. 2 in order to realize a low-loss and small optical coupling portion.

The following method is mentioned as such a surface lens formation method.
The first method is a method of forming a lens with a resist or resin. FIG. 3 is a view showing a cross section of an optical waveguide formed of the underclad 104, the core 106, and the overclad 108 formed on the substrate 102. For example, as shown in FIG. 3, a resin film is formed on the surface of the overcladding 108 (FIG. 3A), and a resist is produced by cylindrical processing of the resin (FIG. 3B), followed by annealing treatment. By doing this (FIG. 3C), there is a method of providing a hemispherical resin to be the lens 160 on the surface. Or there exists the method of providing hemispherical resin used as a lens on the surface by the technique which exposes a resist with the concentric shadow mask with respect to resin formed into a film.

  However, there is a material problem, for example, the resist and the resin are deformed by heat, and the refractive index change due to the temperature is large, so that the lens characteristics are easily changed.

  The second method is a method of transferring the lens shape to the optical circuit surface. For example, as shown in FIG. 4, after a hemispherical shape is formed on the surface with a resist or resin by the same method as the first method (FIG. 4A), the overcladding 108 is formed using the formed resist or resin as a mask. There is a method of transferring the lens shape to the surface by dry etching. This makes it possible to use the overcladding 108 as a lens material, or to use a material previously formed on the overcladding, so that a lens that is not a resin can be formed.

  However, since the transferred lens shape changes depending on the etching selection ratio and speed, errors in the finished lens shape due to slight differences in the selection ratio and speed are likely to occur, making it difficult to produce a desired lens shape. In addition, since the dry-etched surface is rough, loss due to light scattering occurs. Therefore, the method of transferring the hemispherical shape to the surface of the over clad 108 by dry etching is not preferable in lens formation.

  As a third technique for clearing the problems of the above two techniques, a resist is formed on the surface of the PLC (over clad 108) by dry etching as shown in FIG. (FIG. 5B), a cylinder is transferred to the overcladding by dry etching (FIG. 5C), and a hemispherical lens 160 is provided by annealing (FIG. 5D). The processing of the cylindrical shape 144 shown in Fig. 5 (b) can be precisely performed by the conventional photo / dry etching process, so that the processing error is small. Since the surface can be formed, there is a merit that light scattering hardly occurs, and from this advantage, the third method of annealing the cylinder is a method suitable for forming a lens on the PLC surface. That.

JP-A-2005-70365

  However, in order to integrate a plurality of high-speed PDs and LDs that are actually assumed, it is necessary to form a lens uniformly and precisely to collect light. From such a viewpoint, there are two problems.

  The first problem is that it is difficult to produce a lens shape with a small radius of curvature. When a lens is formed by annealing a cylinder, the material melts and spreads around, making it difficult to produce a lens shape with a small radius of curvature. Although methods for reducing the radius of curvature include reducing the diameter of the cylinder and lowering the annealing temperature, the former has the problem of reducing the beam diameter that can enter the lens, while the latter requires precise temperature control. Because of the problem of low reproducibility, there is a limit to the radius of curvature that can be formed. By reducing the radius of curvature, it becomes a highly refracting condensing lens. Therefore, in order to realize high-efficiency optical coupling to various PDs, including high-speed PDs with a small light receiving diameter, lenses with small radius of curvature are used. Realization is necessary.

  The second problem is that the reproducibility and uniformity of lens formation is low. The formed lens shape (height, radius of curvature) varies depending on the columnar shape and column material before annealing and the annealing temperature. As mentioned above, the cylinder can be processed by the conventional photo-etching process, and the columnar material can also use the conventional film formation process (CVD (chemical vapor deposition), sputtering, FHD (Flame Hydrolysis Deposition)), It can be processed with good reproducibility and uniformity. However, since the lens shape changes greatly even when the annealing temperature is different by several degrees, there is a problem that the temperature tolerance is low and therefore the reproducibility is low. Since the annealing temperature is from several hundred degrees to close to 1000 degrees, even a slight temperature gradient caused by the distance from the heater in the heating furnace causes a temperature difference of several degrees to nearly 10 degrees. Due to the position dependency of the temperature in the heating furnace, the position dependency of the lens shape in the wafer surface occurs, and the uniformity is degraded. The low reproducibility and uniformity indicates that when the lens is arrayed and incident on the PD array, the beam diameter varies, and it is difficult to uniformly optically couple to the PD.

  Thus, in surface lenses that are required for downsizing, speeding up, and reducing loss of hybrid integration using a mirror of a PLC platform and optical elements, the lens characteristics have low temperature dependence and smooth light scattering. The formation of a lens having a surface and the formation of a lens with a small radius of curvature and high reproducibility and uniformity are contradictory matters, and the realization of an integrated device capable of achieving high functionality by achieving both of these is an issue. It was.

  The present invention has been made in view of such problems, and an object thereof is to provide an optical waveguide component that realizes low-loss optical coupling with a surface-mounted optical element, and a method for manufacturing the same. provide.

  In order to achieve such an object, one embodiment of the present invention is an optical waveguide component including an optical waveguide provided on a substrate and including a core, an underclad, and an overclad. The optical waveguide component of one embodiment intersects with the exit direction of the core and the port that inputs the signal light to the core or outputs the signal light from the core, provided at the end of the optical waveguide component, and in the vertical direction of the substrate An optical path conversion port in which a mirror with a reflective film is formed at least in a region intersecting with the exit direction of the core, and an optical path conversion at the optical path conversion port. And a convex lens provided on the surface of the over clad through which the transmitted beam passes. In one embodiment, the optical waveguide component includes a partition layer made of a material having a softening temperature higher than that of the material of the overcladding and the convex lens, between the overcladding and the convex lens.

  According to one embodiment of the present invention, a reflective film is provided on an inclined surface provided on a substrate, inclined with respect to an optical waveguide including a core, an underclad, and an overclad, and a vertical direction of the substrate and formed deeper than the core. This is a method of manufacturing an optical waveguide component including a mirror that is attached. In one embodiment, a method of manufacturing an optical waveguide component includes forming a partition layer made of a material having a softening temperature higher than that of the over clad on the over clad, and having a softening temperature substantially equal to that of the over clad on the partition layer. Alternatively, a lens layer made of a low material is formed, and the lens layer is processed into a columnar protrusion by photolithography and etching at a position where a beam whose optical path has been changed by a mirror passes, and a lens processed into a columnar protrusion Melting the protrusions by annealing the layer and forming a convex lens.

  As described above, according to the present invention, it is possible to provide an optical waveguide component that realizes low-loss optical coupling with a surface-mounted optical element, and a method for manufacturing the same.

It is a figure which shows the beam radiate | emitted after optical path conversion from the waveguide of PLC. It is a figure which shows the beam which is optical-path-converted from the waveguide of PLC and is condensed with a lens. It is a figure explaining the manufacturing method of the lens which condenses the beam by which an optical path is changed from the waveguide of PLC. It is a figure explaining the manufacturing method of the lens which condenses the beam by which an optical path is changed from the waveguide of PLC. It is a figure explaining the manufacturing method of the lens which condenses the beam by which an optical path is changed from the waveguide of PLC. It is sectional drawing of the optical waveguide component of one Embodiment of this invention. It is a figure explaining the manufacturing method of the lens which condenses the beam by which an optical path is changed from the waveguide of PLC. It is a figure explaining the manufacturing method of the optical waveguide component of one Embodiment of this invention. It is a top view of the optical waveguide component of one embodiment of the present invention. It is sectional drawing which shows the structure of the optical path change part of the optical waveguide component of one Embodiment of this invention. It is a figure which shows the curvature radius of the lens produced with the manufacturing method of the optical waveguide component of one Embodiment of this invention. It is a figure which shows the height of the lens produced with the manufacturing method of the optical waveguide component of one Embodiment of this invention. It is a top view of the optical waveguide component of one embodiment of the present invention. It is sectional drawing which shows the structure of the optical path change part of the optical waveguide component of one Embodiment of this invention. It is a figure which shows the curvature radius of the lens produced with the manufacturing method of the optical waveguide component of one Embodiment of this invention. It is a figure which shows the height of the lens produced with the manufacturing method of the optical waveguide component of one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As an embodiment of an optical waveguide component that realizes low-loss optical coupling with a surface-mounted optical element, and a method for manufacturing the same, an optical waveguide element and an optical element are obtained by optical path conversion using a mirror in surface integration of a photodiode. An optical waveguide component having a structure capable of optical coupling with low loss when inputting / outputting an optical signal between them and a manufacturing method thereof will be described.

  FIG. 6 is a view showing a cross section of the optical waveguide component of the present embodiment. The optical waveguide component of the present embodiment includes a waveguide formed of an underclad 104, a core 106, and an overclad 108, a partition layer 150, and a lens 160, which are sequentially formed on the Si substrate 102. The mirror 110 is also formed in the PLC plane at an angle of 30 to 60 degrees with respect to the surface of the Si substrate 102, and converts the optical path to input and output an optical signal to the waveguide.

  The partition layer 150 has a higher softening temperature than the overclad. The lens 160 is a microlens 160 formed by forming a columnar protrusion made of a layer having a softening temperature equal to or lower than the softening temperature of the overclad and melting it by annealing.

  By using the optical waveguide component shown in FIG. 6 and condensing the beam expanded at the time of optical signal input / output by the lens 160, the optical coupling efficiency to the photodiode (not shown) above the lens is improved. . By providing the partition layer 150 made of a material having a high softening temperature under the lens 160, the condensing lens 160 having a small curvature radius can be formed. As a result, the focal length is shortened and the optical coupling is reduced. Since the distance is shortened, a small integration can be realized.

As described above, the greatest feature of the present invention is that the optical path conversion mirror, the lens formed on the substrate surface, and the layer having a high softening temperature provided between the lens and the overcladding are formed. It is said. In general, the cross-sectional structure of PLC is that a thin film of SiO ₂ is deposited on an Si or SiO ₂ substrate by about 20 μm as an underclad 104, 3-10 μm as a core 106, and about 20 μm as an overclad 108. Assuming that a mirror 110 having an angle of 45 ° that changes the optical path in the direction perpendicular to the PLC substrate is formed in such a PLC, and the light propagating through the waveguide is bounced up, the beam center on the surface of the overclad 108 The distance from the mirror end is exactly 20 μm. At this time, assuming that a lens having a circular convex with the beam center as the center of the lens is formed, the beam diameter at that time (full width that becomes 1 / e ² intensity of the beam intensity distribution when a Gaussian beam is assumed) However, a lens having a small radius of curvature is necessary to collect the beam that has spread before reaching the lens unit. When optical elements such as PD and LD are integrated on such a mirror with lens, in order to optically couple with low loss, the focal length and beam spot are controlled by controlling the radius of curvature of the lens at 10 to 40 μm. The size is required to match the optical element and its mounting form.

  FIG. 7 is a diagram showing a method for transferring the hemispherical shape described above with reference to FIG. 5 to the surface of the over clad 108. FIGS. 7A to 7C correspond to FIGS. 5A to 5C, respectively. As shown in FIG. 7, when the over clad 108 is simply processed into a cylindrical shape, the cylinder that becomes the lens and the over clad material are the same when annealed. However, since it melts to the over clad side, it is difficult to form a lens with a small radius of curvature. Even when a lens layer having a low softening temperature is provided on the overcladding and processed into a cylinder, it is spread around when annealed, and it is difficult to reduce the radius of curvature. In order to lower the softening temperature of the lens layer, an oxide such as boron or phosphorus is introduced as a dopant, but the over clad is also introduced with a dopant for adjusting the refractive index. This is because it spreads on the over clad which is close to wettability.

  On the other hand, in the present embodiment, such a problem is solved by introducing a partition layer 148 having a lower dopant amount and a higher softening temperature than the lens layer and the over clad layer between the lens layer 108b and the over clad 108a. Thus, a lens having a smaller curvature radius can be realized.

  FIG. 8 is a diagram for explaining a method of manufacturing the optical waveguide component according to this embodiment. As shown in FIG. 8A, before the formation of the mirror, a partition layer 148 having a softening temperature higher than that of the over cladding 108a and having a small amount of dopant is formed on the PLC over cladding 108a. A lens layer 108b having the same softening temperature as that of the overcladding 108a or a softening temperature lower than that of the overcladding is formed thereon, and a resist film is formed thereon. Next, the resist is processed into a cylindrical shape 144 (FIG. 8B).

Thereafter, as shown in FIG. 8B, the cylindrical shape is transferred by photolithography and etching at a position where the beam whose optical path has been changed by the mirror is estimated to pass, and the lens layer 142 is processed into a columnar protrusion (FIG. 8B). 8 (c)). Further, the lens 160 is obtained by annealing the columnar lens layer 142 (FIG. 8D). By annealing, the columnar protrusions are melted and the corners flow to form a smooth surface, thereby obtaining a convex lens shape (FIG. 8D). As the partition layer 148, for example, SiO ₂ without introduction of a dopant is formed on the over clad 108a by CVD or sputtering, a lens layer 108b having a low softening temperature is provided thereon, and a column 146 is formed and annealed. Thus, surface tension is generated due to the difference in wettability between the lens layer 108b and the partition layer 148, and the lens layer 108b is melted without spreading around. As a result, a lens having a small radius of curvature can be realized. At this time, since the partition layer has a small amount of dopant introduced and a small thermal expansion coefficient, defects such as cracks are likely to occur due to thermal expansion and contraction. Therefore, it is desirable to make the partition layer thickness as thin as 2 μm or less. In addition, etching at the time of forming the cylinder is etched to the middle of the partition layer or below the partition layer, and by isolating the lens layer of each cylinder, the lens layer is more effectively prevented from spreading around during annealing. be able to. At this time, in order to suppress the occurrence of defects in the partition layer due to the difference in the thermal expansion coefficient, it is desirable to perform cylindrical etching below the partition layer.

  As described above, in the hybrid integration of the optical waveguide component having the mirror for the optical path conversion and the optical element, by providing a partition layer having a high softening temperature between the over clad and the lens, the integrated device is further improved. It is possible to provide an optical waveguide component that contributes to low loss and downsizing.

Example 1
An optical waveguide component according to Example 1 of the present invention includes an input optical waveguide, and an optical path conversion unit including an optical path conversion mirror and a lens. The optical signal input to the input optical waveguide is bounced up by the mirror (changed in the optical path) and then collected by the lens. Using the above optical waveguide component, the diameter of the beam condensed by the lens was obtained.

  FIG. 9 is a top view of the optical waveguide component. The size of the optical waveguide component shown in FIG. 9 is 5 mm in length and 10 mm in width, the core diameter is 6 μm, the thickness of the over clad as viewed from the top of the core is 14 μm, and the refractive index difference between the core and the clad is 1.5%. A quartz PLC having a waveguide 904 formed on a silicon substrate was used. Optical input is performed from a waveguide (input port) provided on the short side of the PLC, and an optical path conversion unit (optical path conversion port including the mirror 110 and the lens 160) is formed at the center of the chip.

  FIG. 10 is a cross-sectional view showing the structure of the optical path changing unit. As shown in FIG. 10, aluminum is deposited as a reflective film on the inclined surface, and functions as a mirror 110 for changing the optical path of the beam emitted from the inclined surface side of the core 904. At this time, the angle of the inclined surface with respect to the substrate 102 was taken as the mirror angle, and here, the mirror 110 having an angle of 45 ° was formed. The lens 160 is designed so that the center position coincides with the beam center whose optical path has been changed.

Lens formation was performed as follows. First, a SiO ₂ film having a thickness of 1 μm is formed on the PLC as a partition layer, and a lens layer having a softening temperature lower than that of the overcladding is formed thereon by introducing boron and phosphorus oxides as dopants on the lens layer. did. Examples of the film forming method include sputtering, CVD, and FHD, but the present invention is not limited to these film forming methods. Then, after processing the SiO ₂ film introduced with boron and phosphorus oxides as dopants by photolithography and dry etching into a cylinder having a diameter of 10 to 60 μm and a height of 11.5 μm, the cylinder is annealed at 1000 ° C. Thus, a lens 160 was produced. Etching to below the partition layer during cylinder processing not only prevents the lens layer from spreading around during annealing, but also reduces the stress applied to the remaining partition layer and prevents defects such as cracks from occurring. it can. Even in this case, if the thickness of the partition layer is 2 μm or more, defects are likely to occur. Therefore, it is desirable to form a film thinner than 2 μm. The curvature radius and height of the produced lens are shown in FIGS. 11 and 12, respectively. In FIGS. 11 and 12, for comparison, a lens layer is deposited with a thickness of 11 μm without a partition layer, and the curvature radius and height of a lens manufactured by the same procedure as described above are also shown. As shown in FIG. 11, when the partition layer is provided, the radius of curvature of the lens decreases as the diameter of the cylinder decreases, and it is necessary to collect light by setting the diameter of the cylinder in accordance with the desired radius of curvature. It becomes possible to form a lens shape with a radius of curvature of 40 μm or less. On the other hand, when there is no partition layer, the tendency that the radius of curvature of the lens becomes smaller as the diameter of the cylinder becomes smaller is the same, but it can be seen that the minimum radius of curvature does not reach 40 μm or less necessary for light collection. FIG. 12 shows that when there is no partition layer, the lens height decreases as the diameter of the cylinder decreases. This is because the lens layer was melted by annealing and spread around. Since it spreads from the outer peripheral side of the cylinder, it can be said that the height is less likely to decrease as the diameter of the cylinder increases. However, when the partition layer is provided, it can be seen that the lens height is constant without decreasing. This indicates that the lens layer melts while staying in place without spreading around, and the lens layer spreads around while controlling wettability by using the above cylindrical structure. It was confirmed that In a PLC provided with a partition layer, light with a wavelength of 1.55 μm was actually input and the beam bounced up by a mirror was evaluated. In a lens made from a cylinder with a diameter smaller than 40 μm, the beam without a lens was obtained. It was confirmed that light can be condensed to a beam diameter smaller than the diameter. As described above, by using the optical waveguide component in which the partition layer having a high softening temperature is provided between the overcladding and the lens of the present invention, a lower-loss optical device can be easily provided.

(Example 2)
An optical waveguide component according to Example 2 of the present invention includes an input optical waveguide and an optical path conversion unit including an optical path conversion mirror and a lens. After producing PLC and forming a lens, the lens shape was evaluated. Finally, an optical waveguide component was manufactured by forming an optical path conversion mirror.

  FIG. 13 is a top view of the optical waveguide component. . The size of the optical waveguide component in FIG. 13 is 5 mm in length and 10 mm in width, the core diameter is 4.5 μm, the over clad film thickness as viewed from the top of the core is 15.5 μm, and the refractive index difference between the core and the clad is 2 A quartz PLC with a 5% waveguide 904 formed on a silicon substrate was used. Optical input is performed from a waveguide 904 (input port) provided on the short side of the PLC, and an optical path conversion unit (optical path conversion port including the mirror 110 and the lens 160) is formed at the center of the chip.

  FIG. 14 is a cross-sectional view showing the structure of the optical path changing unit. As shown in FIG. 14, aluminum is deposited as a reflective film on the inclined surface, and functions as a mirror 110 for changing the optical path of the beam emitted from the inclined surface side of the core 904. At this time, the angle of the inclined surface with respect to the substrate 102 was taken as the mirror angle, and here, the mirror 110 having an angle of 45 ° was formed. The lens 160 is designed so that the center position coincides with the beam center whose optical path has been changed.

As the PLC, one in which the above-mentioned optical waveguide components are arranged in 20 rows and 10 rows on a 6-inch wafer was used. Lens formation was performed as follows. First, a SiO ₂ film having a thickness of 0.5 μm is formed on the PLC as a partition layer, and a lens layer having a softening temperature lower than that of the overcladding is introduced thereon as a lens layer by introducing boron and phosphorus oxides as a lens layer to 6 μm. A film was formed. Examples of the film forming method include sputtering, CVD, and FHD, but the present invention is not limited to these film forming methods. Thereafter, the SiO ₂ film in which boron and phosphorus oxides were introduced as dopants by photolithography and dry etching was processed into a cylinder having a diameter of 30 μm and a height of 7 μm including overetching into the overclad. Three such wafers were produced and annealed at 990, 1000, and 1010 ° C. using a muffle furnace, respectively, to produce optical waveguide components. Etching to below the partition layer during cylinder processing not only prevents the lens layer from spreading around during annealing, but also reduces the stress applied to the remaining partition layer and prevents defects such as cracks from occurring. it can. Even in this case, if the thickness of the partition layer is 2 μm or more, defects are likely to occur. Therefore, it is desirable to form a film thinner than 2 μm.

  FIG. 15 and FIG. 16 show the curvature radius and height of the manufactured lens at each wafer in-plane position, respectively. In FIGS. 15 and 16, for comparison, a lens layer is deposited with a thickness of 7 μm without a partition layer, and the curvature radius and height of a lens manufactured by the same procedure as described above are also shown. From FIG. 15, it can be seen that the radius of curvature is smaller with the partition layer than with the partition layer when the wafer center is seen. This is because the lens layer is prevented from spreading around by providing the partition layer. Further, without the partition layer, the radius of curvature increases as the annealing temperature increases. At this time, when the lens height is seen, the height decreases as the annealing temperature increases, so it can be seen that the higher the temperature, the lower the viscosity of the melted lens layer and the easier it is to spread around. On the other hand, when the partition layer is provided, the change in the radius of curvature due to the change in the annealing temperature is small, and even if the viscosity of the melted lens layer changes due to the temperature, the lens layer is surrounded by the cylindrical partition layer. Spreading is suppressed. Therefore, at a temperature equal to or higher than the temperature at which the lens layer melts, the shape of the formed lens can be controlled by the cylindrical shape before annealing, and the lens shape can be produced with higher reproducibility. Here, comparing the lens shape between the wafer center and its left and right, without the partition layer, the outer curvature radius is large and the height is low, and the lens layer is likely to melt from the wafer center toward the outside. You can see that This is because a temperature gradient is generated inside the muffle furnace near the heater part and inside away from the heater, and the outside temperature is high. On the other hand, when the partition layer is provided, the position dependency of the lens shape is low in the wafer surface as described above, and the lenses are uniformly formed. This is because the change of the lens shape due to the temperature change is suppressed by providing the partition layer.

  As described above, by providing the partition layer, the change in the lens shape with respect to the temperature change is suppressed, and the temperature tolerance is improved. As a result, an optical waveguide component in which a plurality of lenses are formed uniformly and with good reproducibility can be realized, and a lower-loss optical device can be easily provided.

100 PLC
102 Substrate 104 Underclad 106 Core 108, 108a Overclad 108b Lens layer 110 Mirror 142 Resin / resist 148, 150 Partition layer 160 Condensing lens 200 High-speed PD
202 Light receiving portion 902 Optical input portion 904 Waveguide

Claims (6)

An optical waveguide component including an optical waveguide provided on a substrate and including a core, an underclad, and an overclad,
A port provided at an end of the optical waveguide component for inputting signal light to the core or outputting signal light from the core;
A mirror that has a reflective film deposited on at least a region of the inclined surface that intersects the emission direction of the core, is inclined with respect to the vertical direction of the substrate, and is formed deeper than the core. An optical path conversion port formed with
A convex lens provided on the surface of the over clad through which the beam whose optical path has been converted passes through the optical path conversion port;
An optical waveguide component comprising a partition layer made of a material having a softening temperature higher than that of the material of the overcladding and the convex lens between the overcladding and the convex lens.   The optical waveguide component according to claim 1, wherein a thickness of the partition layer in a vertical direction of the substrate is 2 μm or less.   The optical waveguide component according to claim 1, wherein the partition layer having a columnar shape is provided only under the convex lens. An optical waveguide comprising a core, an underclad and an overclad provided on the substrate, and a mirror which is inclined with respect to a vertical direction of the substrate and has a reflective film deposited on an inclined surface formed deeper than the core. Forming a partition layer made of a material having a softening temperature higher than that of the overclad on the overclad of the optical waveguide component provided;
Forming a lens layer made of a material having a softening temperature substantially equal to or lower than that of the over clad on the partition layer;
Processing the lens layer into a columnar protrusion by photolithography and etching at a position where the beam whose optical path has been changed by the mirror passes;
An optical waveguide component manufacturing method comprising: annealing the lens layer processed into a columnar protrusion to melt the protrusion to form a convex lens.   5. The method of manufacturing an optical waveguide component according to claim 4, wherein the columnar protrusion has a cylindrical shape and a diameter of 40 [mu] m or less. The partition layer is SiO _2, the optical waveguide component manufacturing method according to claim 4 or 5, characterized in that.