JP2017201364A - Optical transceiver module, and adjustment method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical transceiver module having a wide mounting tolerance and a simple structure.SOLUTION: An optical transceiver module is constituted by a first substrate 101a and a second substrate 108 in surface contact with each other. The first substrate includes a first light incidence part and a first light emission part, on a first surface of the first substrate. The second substrate includes a second light incidence part, a second light emission part, and a third light incidence part, on a second surface of the second substrate, and includes a lens 103 for collecting input light, on a third surface opposite to the second surface of the second substrate. The first surface and the second surface face each other in contact with each other. The lens and the first light incidence part 110 are optically connected. The first light incidence part and the first light emission part 111 are optically connected. The first light emission part and the second light incidence part 105 are optically connected. The second light incidence part and the second light emission part 106 are optically connected to transmit light from the second light emission part. The light is received in the third light incidence part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical transceiver module and an adjustment method thereof.

  With the expansion of big data business and the spread of IoT (Internet of Things), IP (Internet Protocol) traffic in data centers is increasing. Particularly in recent years, with the progress of server virtualization technology, traffic within a server or between multiple servers has increased rapidly, and approximately 80% of the total IP traffic processed in the data center. Is the traffic that stays in the data center.

  Under such circumstances, the network performance of communication (interconnect) at relatively short distances connecting the inside of ICT (Information and Communication Technology) devices such as servers, storage, and transmission devices, or between ICT devices, is data. It is becoming a factor that limits the amount of traffic that can be processed at the center. For this reason, expectations for increasing the capacity of interconnects are further increasing.

  Conventionally, an electrical interconnect using an electrical cable has been used for communication within an ICT device or between ICT devices at a short distance. However, if the transmission rate per channel is increased to 10 to 25 Gbps or more in response to the demand for increasing the capacity of the interconnect, an increase in transmission loss of high-frequency signals and an accompanying increase in power consumption are noticeable in the electrical interconnect. Become.

  In addition, signal leakage (crosstalk) between signal lines due to generation of high-frequency noise due to high speed becomes a major issue. As a technique for overcoming this problem, an optical interconnect that has been attracting attention in recent years is an optical interconnect that connects an apparatus or an apparatus with an optical fiber cable. Optical signals are promising for high-capacity interconnects because they have less crosstalk between lines and less signal quality degradation due to transmission distance than electrical signals.

  In an optical interconnect, an electrical signal is once converted into an optical signal, and after a desired distance is transmitted through an optical fiber cable or an optical waveguide, the optical signal is converted into an electrical signal again. Therefore, the optical interconnect requires a light emitting element for converting an electrical signal into an optical signal and a light receiving element for converting the optical signal into an electrical signal.

  An optical interconnect module using a vertical cavity surface emitting laser (VCSEL) as a light emitting element has already been put into practical use. The optical interconnect system using the VCSEL is a system in which an electrical signal modulated at high speed is directly input to a light emitting element, and the light emitting element itself generates an optical signal modulated at high speed, and is called a direct modulation system.

  In recent years, silicon photonics technology has attracted attention for further increase in capacity. The silicon photonics technology is a general term for technologies for producing an optical circuit and an optical module in which the electronic circuit is integrated with the silicon wafer process technology and packaging technology that are highly developed for LSI manufacturing. By using silicon photonics technology and integrating a large number of electrical / optical signal conversion elements with high yield and accuracy in a silicon wafer, the capacity of the optical interconnect module can be increased.

  If silicon photonics technology is used, an optical modulator having a Mach-Zehnder interferometer structure or the like can be manufactured as an electrical / optical signal conversion element. If an optical modulator is used, it is not necessary to directly modulate the light emitting element, and an optical signal having a constant intensity emitted from the light emitting element can be modulated at high speed by the optical modulator. An optical modulation method that separates the light emitting function and the function of converting an electrical signal into an optical signal at a high speed is called an external modulation method.

  Since the external modulation method is less likely to cause distortion in the optical signal waveform than the direct modulation method, it can be modulated at higher speed. In addition, wavelength division multiplexing (WDM) for simultaneously transmitting a plurality of optical signals of different wavelengths, which is difficult with an optical interconnect module using a VCSEL, and by placing phase information and polarization information on an optical signal, Since optical multilevel modulation in which information of a plurality of bits is transmitted simultaneously with an optical signal is possible, the capacity can be further increased.

  Expectations for silicon photonics technology are not limited to large capacity. It is highly expected to reduce the cost of optical modules by using wafer processes and packaging equipment designed for mass production of LSIs. In addition, it is expected that the power required for driving the optical element can be suppressed by miniaturizing the optical element by taking advantage of the large refractive index difference between silicon and silicon dioxide. Furthermore, compared to the direct modulation method, since the amount of distortion is small in the waveform received when the optical signal is transmitted for a certain distance, long distance transmission is possible.

  In summary, the main expectations for optical interconnect modules fabricated using silicon photonics technology are large capacity, low cost, power saving, and long distance transmission.

  In an optical interconnect system using an external modulation system, a technique for optically coupling a light emitting element and an optical modulator with high efficiency is a key technology. In the optical interconnect system using the WDM system effective for increasing the capacity, a technique for optically coupling a light emitting element, a light receiving element, and a wavelength multiplexer / demultiplexer with high efficiency is a key technique.

  Patent Document 1 discloses a structure in which light emitted from a semiconductor laser is coupled to a wavelength multiplexer / demultiplexer on a plane parallel to the housing surface. The semiconductor laser and the wavelength multiplexer / demultiplexer can be combined with high efficiency. A structure in which an independent lens is provided between a semiconductor laser and a wavelength multiplexer / demultiplexer for optical coupling is disclosed.

JP 2012-58409 A

  In a wavelength division multiplexing optical transceiver module using an external modulation method capable of high-speed, large-capacity, long-distance transmission, a process of mounting an optical circuit element on which a semiconductor laser and an optical modulator are formed, and an optical modulator are formed A step of mounting the optical circuit element and the wavelength multiplexer / demultiplexer is required. Since these mountings usually require high positioning accuracy, an expensive mounting apparatus is required, and the time required for mounting becomes long, resulting in an increase in mounting cost.

  In addition, in order to mount these optical elements with high optical coupling efficiency, a lens for condensing light is separately required. As the number of parts to be mounted increases, there are problems such as an increase in material cost and an increase in module size.

  More importantly, the problem described above becomes more prominent as the demand for larger capacity increases. The 100-Gigabit Ethernet (100GbE) -compatible module (Ethernet is a registered trademark), which is currently in widespread use, is a system that multiplexes 25-Gbps modulated light at 4 wavelengths, while it supports the next-generation 400 Gigabit Ethernet (400GbE) In the module, the light modulated at 50 Gbps is multiplexed by 8 wavelengths. When the number of wavelengths to be multiplexed is doubled, the variation in coupling efficiency between wavelengths tends to increase, and there is a concern that problems related to mounting optical elements will become more prominent.

  Thus, when the number of wavelengths to be multiplexed in the future increases, the structure disclosed in Patent Document 1 has high optical coupling efficiency, small variation between wavelengths, and high-density light by a simple and inexpensive method. It is difficult to mount the element.

  An object of the present invention is to provide an optical transceiver module having a wide mounting tolerance and a simple structure.

  The present invention includes a plurality of means for solving the above-described problems. To give an example, the optical transceiver module is configured such that the first substrate and the second substrate are in surface contact with each other. The first substrate includes a first light incident portion and a first light emitting portion on a first surface of the first substrate, and the second substrate is a second portion of the second substrate. Including a second light incident portion, a second light emitting portion, and a third light incident portion, and on the third surface opposite to the second surface in the second substrate, A lens for condensing input light, wherein the first surface and the second surface are opposed to and in contact with each other, and the lens and the first light incident portion are optically connected, 1 light incident part and the first light emitting part are optically connected, the first light emitting part and the second light incident part are optically connected, and the second light incident part And said second light emitting portion is optically connected, wherein the light is transmitted from the second light emitting portion, wherein the third light the light incident portion is received.

  According to the present invention, it is possible to provide an optical transceiver module having a wide mounting tolerance and a simple structure.

3 is an example of a cross-sectional view of a main part of the optical transmission module according to Embodiment 1. FIG. FIG. 3 is an example of a top view of a main part of the optical transmission module according to the first embodiment. 2 is an example of a quartz optical waveguide device optical coupling part of Example 1. FIG. It is an example of a silicon optical waveguide device optical coupling part (input side). It is an example of a silicon optical waveguide device optical coupling part (output side). FIG. 10 is an example of a top view of a main part of a modification of the optical transmission module according to the first embodiment. 6 is an example of a cross-sectional view of a main part of an optical transmission module according to Embodiment 2. FIG. FIG. 10 is an example of a top view of a main part of an optical transmission module according to a second embodiment. FIG. 12 is an example of a cross-sectional view of a main part of a modification of the optical transmission module according to the second embodiment. FIG. 10 is an example of a top view of a main part of a modification of the optical transmission module according to the second embodiment. FIG. 10 is an example of a top view of a main part of an optical transmission module according to a third embodiment. FIG. 10 is an example of a top view of a main part of an optical transmission module according to a fourth embodiment. 10 is an example of a cross-sectional view of a main part of an optical transmission module according to Embodiment 4. FIG. 10 is an example of a cross-sectional view of a main part of an optical transceiver module according to Embodiment 5. FIG. EXAMPLE 5 It is an example of the principal part top view of an optical transmission / reception module.

  The optical transceiver module according to each embodiment of the present invention will be described in detail below. The drawings shown below are only for explaining examples of the embodiments, and the size of the drawings and the scales described in the examples do not necessarily match. Moreover, the same code | symbol is attached | subjected to the same component and those description is not repeated.

  An optical transceiver module in which a semiconductor laser and a wavelength multiplexer / demultiplexer are mounted in an optical circuit, having high optical coupling efficiency, small variation between wavelengths, and a simple and inexpensive structure with high density A configuration of an optical transceiver module capable of mounting an optical element will be described. From the viewpoint of optical coupling efficiency, a module in which all components are monolithically integrated on a single substrate is desirable.

  Here, monolithic integration refers to integration on a substrate at a time by a photolithography process used in semiconductor manufacturing. In general, the positioning accuracy of each component in monolithic integration depends on the alignment accuracy of the photomask, and is as high as ± 1 μm or less. Therefore, the position shift between each component does not easily occur, and high optical coupling efficiency is easily obtained.

  On the other hand, the hybrid integration compared with the monolithic integration refers to the integration of separately manufactured components using a mounting apparatus. In general, the positioning accuracy of each component in hybrid integration depends on the alignment accuracy of the apparatus, and is about ± 10 μm. Compared to monolithic integration, positioning accuracy is low, and high optical coupling efficiency is difficult to obtain.

  In addition, the monolithically integrated module has an additional advantage that the mounting process is simplified. Since it is not necessary to provide a mechanism for adjusting the position of each component with high accuracy, it is possible to integrate the parts with high density.

  However, there are three major issues regarding monolithic integration using silicon photonics technology. The first is that when an optical circuit is formed of a silicon material, the silicon material is an indirect transition material, and its emission intensity is extremely weak, so that it is very difficult to monolithically integrate semiconductor lasers.

  Second, when a wavelength multiplexer / demultiplexer made of a silicon material is monolithically integrated in an optical circuit, it is necessary to directly connect the silicon optical circuit and the optical fiber. Since it is difficult to make the mode field diameter of the light emitted from the silicon optical circuit equal to the mode field diameter of the optical fiber, it is difficult to obtain high optical coupling efficiency due to mode mismatch.

  Third, when a wavelength multiplexer / demultiplexer made of a silicon material is monolithically integrated in an optical circuit, the wavelength to be multiplexed / demultiplexed changes depending on the temperature due to the nature of the silicon material. Therefore, it is necessary to provide a temperature regulator to keep the wavelength to be multiplexed / demultiplexed constant. The temperature regulator is generally very large and consumes much power compared to an optical element.

  For the above three reasons, in order to achieve both high optical coupling efficiency, small size, and power saving, it is preferable to form the semiconductor laser and the wavelength multiplexer / demultiplexer from materials other than silicon and to hybridly mount them on the optical circuit.

  Next, with respect to the form in which the semiconductor laser is mounted on the optical circuit, since the light emitted from the semiconductor laser generally has a certain radiation angle, the radiation beam spreads away from the emission surface. In general, the size of a beam emitted from a semiconductor laser is about several μm in diameter. On the other hand, the diameter of the optical waveguide formed on the optical circuit to which the emitted light is coupled is several hundred nm. Therefore, in order to combine with high efficiency, it is preferable to collect the emitted light with a lens.

  The optical transmission module based on the above is an optical transmission module in which a semiconductor laser and a wavelength multiplexer / demultiplexer are hybrid-mounted on a silicon optical circuit. A typical example of the embodiment is the first surface of the first substrate. A first light incident diffraction grating type optical coupler and a first light emitting diffraction grating type optical coupler are provided on the second surface of the second substrate. A reflection mirror type optical coupler, wherein the first surface and the second surface are connected to face each other, the first light emitting diffraction grating type optical coupler and the second light incident reflection mirror type; A hybrid mounting optical module optically connected to an optical coupler, and condenses light input on a third surface opposite to the second surface of the second substrate. A convex lens having a function is formed, and the first light incident diffraction grating optical coupler and the convex lens An optical transmission module, characterized in that it is optically connected.

  The configuration of the first embodiment will be described with reference to FIGS. FIG. 1 is an example of a cross-sectional view of main parts of a wavelength multiplexer and an optical circuit in the optical transmission module described in the first embodiment. FIG. 2 is an example of a top view of the main part.

  The optical transmission module shown in FIGS. 1 and 2 includes a quartz optical waveguide element substrate 101a, a quartz optical waveguide layer 102, a convex lens 103, a reflecting mirror 104, a quartz optical waveguide element optical coupling portion 105, a quartz optical waveguide end face 106, and an optical fiber mounting. A V-groove 107, a silicon optical waveguide device substrate 108, a silicon optical waveguide layer 109, a silicon optical waveguide device optical coupling portion (input side) 110, and a silicon optical waveguide device optical coupling portion (output side) 111 are configured.

  A quartz optical waveguide 113 and an optical multiplexer 114 are configured in the quartz optical waveguide layer 102, and a silicon optical waveguide 127 is configured in the silicon optical waveguide layer 109. In FIG. 113 and the optical multiplexer 114 overlap the quartz optical waveguide layer 102, and the silicon optical waveguide 127 overlaps the silicon optical waveguide layer 109 and cannot be identified. In FIG. 2, the quartz optical waveguide layer 102, the silicon optical waveguide layer 109, and the like cannot be identified from the top view of the main part, and are not shown.

  As shown in FIG. 1, the quartz optical waveguide device substrate 101a and the silicon optical waveguide device substrate 108 are stacked and mounted so as to contact each other, and the quartz optical waveguide device substrate 101a is disposed on the quartz optical waveguide layer 102 on the contact surface. The silicon optical waveguide device substrate 108 includes a silicon optical waveguide layer 109.

  A convex lens 103 is formed on the quartz optical waveguide device substrate 101a, and the light 112 is incident thereon. A reflecting mirror 104 is formed on one end face of the quartz optical waveguide element substrate 101a, and an optical fiber mounting V-groove 107 is formed on the other end face.

  The reflecting mirror 104 on one end face of the quartz optical waveguide layer 102 constitutes a quartz optical waveguide element optical coupling portion 105, and the optical fiber mounting V-groove 107 on the other end face has a quartz optical waveguide end face 106 to which an optical fiber is connected. There is. The quartz optical waveguide layer 102 and the quartz optical waveguide 113 include at least one of SiO2, SiN, and SiON as materials.

  The core layer and the cladding layer of the quartz optical waveguide element optical coupling portion 105 and the quartz optical waveguide layer 102 will be described later with reference to FIG. An optical multiplexer 114 is formed in the quartz optical waveguide layer 102, and as shown in FIG. 2, the light from the plurality of quartz optical waveguides 113 is combined and the combined light is emitted to the end surface 106 of the quartz optical waveguide. The above-described configuration of the quartz optical waveguide device substrate 101a is a quartz optical waveguide device, which is a wavelength multiplexer.

  The silicon optical waveguide layer 109 of the silicon optical waveguide element substrate 108 includes a silicon optical waveguide element optical coupling part (input side) 110 and a silicon optical waveguide element optical coupling part (output side) 111. These and the core layer and cladding layer of the silicon optical waveguide layer 109 will be described later with reference to FIGS. The above configuration of the silicon optical waveguide element substrate 108 is an optical circuit. The material of the silicon optical waveguide layer 109 and the silicon optical waveguide 127 may be Si.

  As shown in FIG. 2, a silicon optical waveguide 127 is formed between the position where the light 112 is incident from the convex lens 103 and the reflecting mirror 104, and the position where the light from the silicon optical waveguide 127 is reflected by the reflecting mirror 104 and the optical coupling. A quartz optical waveguide 113 is formed between the waver 114. In order to easily distinguish the silicon optical waveguide 127 and the quartz optical waveguide 113 on the drawing, the silicon optical waveguide 127 is represented by a broken line and the quartz optical waveguide 113 is represented by a solid line. Here, one silicon optical waveguide 127 and one quartz optical waveguide 113 correspond one-to-one.

  For example, the positional relationship between the quartz optical waveguide device optical coupling portion 105 and the silicon optical waveguide device optical coupling portion (output side) 111 in FIG. 1, that is, the silicon optical waveguide 127 and the quartz optical waveguide 113 in the reflecting mirror 104 in FIG. The positional relationship of the overlaps affects the optical coupling efficiency between the silicon optical waveguide 127 and the quartz optical waveguide 113. As an example of the allowable range of the positional relationship, the dotted line range 130 shown in FIG.

  The first feature of the optical transmission module shown in FIGS. 1 and 2 is that a convex lens 103 is formed on a quartz optical waveguide device substrate 101a. When the convex lens 103 is not formed, a separate lens is required to input light emitted from the semiconductor laser to the optical circuit. On the other hand, since the convex lens 103 is formed on the quartz optical waveguide device substrate 101a, it is not necessary to provide a separate lens, and the number of components can be reduced by one. Therefore, the component cost can be reduced and the module size can be reduced.

  The second feature of the optical transmission module shown in FIGS. 1 and 2 is that the quartz optical waveguide device substrate 101a and the silicon optical waveguide device substrate 108 are stacked and mounted such that the surfaces on which the circuit layers are formed face each other. It is a point. Compared to a mounting form in which the side surfaces of each substrate face each other and the optical waveguides formed on each substrate are butt-connected, the mounting tolerance is wide.

  In general, in the case of a mounting form for butt connection, an alignment accuracy of about 0.2 μm is required, whereas in the stacked mounting form, the alignment accuracy can be relaxed to 1 μm or more. This is because a diffraction grating type optical coupler can be used as an optical coupler for connecting two different optical waveguides with high optical coupling efficiency. A configuration using a diffraction grating type optical coupler will be described later with reference to FIGS.

  In order to increase the mounting tolerance, it is also effective to increase the mode field diameter of light emitted from or incident on the optical element. However, in the diffraction grating type optical coupler, the mode field of light at the design level is effective. It is relatively easy to enlarge the diameter.

  As described above, since the convex lens 103 is formed on the quartz optical waveguide device substrate 101a, it is possible to reduce the number of components, thereby reducing the cost, and downsizing the module size. Since the silicon optical waveguide element substrate 108 is stacked and mounted so that the surfaces on which the circuit layers are formed face each other, the mounting tolerance is wide.

  Here, what is more important as the effect of the optical transmission module shown in FIGS. 1 and 2 is that the number of times of high-precision optical element alignment mounting is required only once. In the conventional configuration, it was necessary to align the lens and the wavelength multiplexer independently of each other with high precision, whereas in the optical transmission module shown in FIGS. 1 and 2, the lens and the wavelength multiplexer were integrated. Because of the integration, high-precision alignment is required only once.

  In other words, if only the wavelength multiplexer and the optical circuit are aligned, the position of the lens can be adjusted to a desired position of the optical circuit with high accuracy. A decrease in the number of alignments leads to a reduction in manufacturing cost by improving the throughput of optical module manufacturing. If the light emitted from the semiconductor laser is collimated light, tolerance for mounting the semiconductor laser in the optical circuit can be greatly relaxed, so there is no need for high-precision mounting, and high optical coupling efficiency with simple mounting. Can be obtained.

  In FIG. 2, eight lenses are integrated, and the form of an optical module that multiplexes and transmits light of 8 wavelengths is illustrated, but the number of lenses and the number of wavelengths to be combined are limited to this. However, it may be two or more.

  Next, the optical coupling unit will be described in more detail with reference to FIGS. The quartz optical waveguide device optical coupling portion 105 shown in FIG. 3 includes a reflecting mirror 104, a quartz optical waveguide core layer 116, and a quartz optical waveguide cladding layer 117 (a combination of an upper cladding layer 117a and a lower cladding layer 117b). A reflection type optical coupler formed by including a waveguide cladding layer 117.

  The reflecting mirror 104 is constituted by a quartz optical waveguide core layer 116 and a quartz optical waveguide cladding layer 117, and light 118 incident from a substantially vertical direction with respect to the plane of the quartz optical waveguide element substrate 101 a. The light is reflected to the quartz optical waveguide 113 that coincides with the core layer 116 so as to become light 119.

  As shown in FIG. 3, the optical path of the light 118 is slightly inclined from the vertical direction of the quartz optical waveguide device substrate 101a. The angle θ formed between the plane parallel to the quartz optical waveguide element substrate 101a and the reflecting mirror 104 is preferably 40 ° to 50 °.

  Examples of the silicon optical waveguide device optical coupling section (input side) 110 shown in FIG. 4 and the silicon optical waveguide device optical coupling section (output side) 111 shown in FIG. 5 include diffraction gratings 122a and 122b, and a silicon optical waveguide, respectively. This is a diffraction grating type optical coupler formed including a core layer 120 and a silicon optical waveguide clad layer 121 (the upper clad layer and the lower clad layer are combined into a silicon optical waveguide clad layer 121).

  Here, as shown in FIG. 4, the diffraction grating 122 a utilizes the second-order diffraction phenomenon of light, and the light 123 incident from a substantially perpendicular direction (incident angle θ) with respect to the plane of the silicon optical waveguide element substrate 108. Is emitted to the silicon optical waveguide 127 which is constituted by the silicon optical waveguide core layer 120 and the silicon optical waveguide cladding layer 121 and coincides with the silicon optical waveguide core layer 120 in the cross-sectional view so as to become light 124.

  On the other hand, as shown in FIG. 5, the diffraction grating 122b substantially transmits light 124 propagating through the silicon optical waveguide 127 that coincides with the silicon optical waveguide core layer 120 in the sectional view with respect to the plane of the silicon optical waveguide element substrate 108. The light 125 is emitted in the vertical direction (emission angle θ). As shown in FIGS. 4 and 5, the optical paths of the input light 123 and the output light 125 are inclined by θ from the vertical direction (thin line) of the silicon optical waveguide element substrate 108, and the angles θ are 0 respectively. Desirably, the angle is between 12 ° and 12 °.

  Next, as a modification of the optical transmission module of the first embodiment, an optical transmission module for coupling a quartz optical waveguide device optical coupling portion 105 and a silicon optical waveguide device optical coupling portion (output side) 111 with high optical coupling efficiency. Will be described with reference to FIG. In order to couple with high optical coupling efficiency, it has a structure for adjusting the positional relationship in which the quartz optical waveguide device substrate 101b and the silicon optical waveguide device substrate 108 are stacked.

  In contrast to the optical transmission module shown in FIG. 2, the quartz optical waveguide device substrate 101b has V-grooves 126a and 126b for mounting optical fibers for alignment, and quartz optical waveguides 113a and 113b are formed in the vicinity thereof. A reflecting mirror 104 is formed on the other end face of each of the quartz optical waveguides 113a and 113b.

  On the other hand, an alignment silicon optical waveguide 127a is formed on the silicon optical waveguide element substrate 108, and silicon optical waveguide element optical coupling portions (input side) 110 are provided at both ends of the silicon optical waveguide element substrate 108 at a position where the reflecting mirror 104 is laminated. A silicon optical waveguide device optical coupling portion (output side) 111 is formed. In order to distinguish the alignment silicon optical waveguide 127a from the quartz optical waveguides 113a and 113b, the alignment silicon optical waveguide 127a is indicated by a broken line in FIG.

  With this configuration, light input from the alignment optical fiber mounting V-groove 126a side passes through the quartz optical waveguide 113a, is reflected by the reflecting mirror 104, and is input to the silicon optical waveguide element optical coupling portion (input side) 110. Then, the silicon optical waveguide 127a for alignment is advanced. The light traveling through the alignment silicon optical waveguide 127a is input to the reflecting mirror 104 from the silicon optical waveguide element optical coupling portion (output side) 111, reflected by the reflecting mirror 104, travels through the quartz optical waveguide 113a, and the alignment light. Output from the fiber mounting V-groove 126b side.

  An optical fiber is connected to each of the alignment optical fiber mounting V-grooves 126a and 126b, light is input from one optical fiber, light output from the other optical fiber is detected, and the detected light intensity is maximized. Further, if the positional relationship between the quartz optical waveguide device substrate 101b and the silicon optical waveguide device substrate 108 is adjusted, the two substrates can be optically coupled. Here, since it is not necessary to perform alignment by inputting light to the convex lens 103 using a semiconductor laser, there is an advantage that alignment can be performed more accurately and easily.

  For example, the quartz optical waveguide device substrate 101a and the silicon optical waveguide device substrate 108 are fixed to each of the two fixing devices whose positional relationships can be changed by a motor or an actuator, and the alignment optical fiber is mounted. Light is input from the optical fiber connected to the V-groove 126a for use, and light output from the optical fiber connected to the V-groove 126b for mounting the alignment optical fiber is monitored.

  A computer controls the positional relationship between the two fixtures to scan two-dimensionally, records the intensity of the monitored light along with the positional relationship, and records the highest intensity of light after the two-dimensional scan is completed. The two fixtures may be controlled to move to a positional relationship, and the quartz optical waveguide device substrate 101a and the silicon optical waveguide device substrate 108 may be controlled to adhere.

  As described above, it is an optical transmission module in which a semiconductor laser and a wavelength multiplexer are mounted on an optical circuit, and has a high optical coupling efficiency and high density in a simple and inexpensive process. It is possible to configure an optical transmission module in which is mounted.

  Next, Example 2 will be described with reference to FIGS. FIG. 7 is an example of a principal part sectional view of the wavelength multiplexer and the optical circuit in the optical transmission module described in the second embodiment, and FIG. 8 is an example of a principal part top view.

  7 and 8 includes a quartz optical waveguide element substrate 101c, a quartz optical waveguide layer 102, a convex lens 103, a prism reflecting mirror mounting recess 201, a prism reflecting mirror 202, a quartz optical waveguide end face 106, and an optical fiber mounting V. Groove 107, silicon optical waveguide device substrate 108, silicon optical waveguide layer 109, silicon optical waveguide device optical coupling portion (input side) 110, silicon optical waveguide device optical coupling portion (output side) 111, quartz optical waveguide 113, optical multiplexer 114 and a silicon optical waveguide 127.

  The quartz optical waveguide device substrate 101c is provided with a recessed space as a prism reflecting mirror mounting recess 201, and a prism reflecting mirror 202 is provided in the space. The prism reflecting mirror 202 has a reflecting surface 202a. Like the reflecting mirror 104 described with reference to FIG. 3, the reflecting surface 202a transmits light incident from the silicon optical waveguide element optical coupling portion (output side) 111 to quartz. Reflected to the optical waveguide 113.

  In the optical transmission module of the first embodiment, the coupling position between the quartz optical waveguide device substrates 101a and 101b and the silicon optical waveguide device substrate 108 is the end face of the quartz optical waveguide device substrates 101a and 101b. However, the coupling position is not limited to the end face, and therefore the structure of the quartz optical waveguide device optical coupling part 105 is different.

  Since the quartz optical waveguide device optical coupling portion 105 described with reference to FIGS. 1 and 3 has a different structure as the optical coupling portion, the characteristics as the optical transmission module are as described in the first embodiment. is there. That is, in the optical transmission module according to the second embodiment, the convex lens 103 is formed on the quartz optical waveguide device substrate 101c. Therefore, the number of components can be reduced, thereby reducing the cost and reducing the module size.

  Further, since the quartz optical waveguide device substrate 101c and the silicon optical waveguide device substrate 108 are stacked and mounted such that the surfaces on which the circuit layers are formed face each other, the mounting tolerance is wide, and the convex lens 103 and the wavelength multiplexer are combined. Therefore, if only the wavelength multiplexer and the optical circuit are aligned, the position of the convex lens 103 can be adjusted with high accuracy to the desired optical circuit. Can be adjusted to the position of

  The optical transmission module according to the second embodiment is characterized in that the position of the prism reflector mounting recess 201 serving as the quartz optical waveguide element optical coupling portion is not limited to the end face of the quartz optical waveguide element substrate 101c. It can be formed at any position on the element substrate 101c. This has the advantage that the degree of freedom in designing the quartz optical waveguide element and the silicon optical waveguide element is increased.

  Since there is no need to forcibly bend or extend the optical waveguide if the degree of design freedom increases, optical loss can be reduced and the chip size can be reduced, and the optical transmission module can be made to have higher performance, smaller size, and lower cost. Can do.

  Next, a modification of the optical transmission module according to the second embodiment will be described with reference to FIGS. FIG. 9 is a cross-sectional view of main parts of a wavelength multiplexer and an optical circuit in a modification of the optical transmission module according to the second embodiment, and FIG. 10 is a top view of main parts. The prism reflecting mirror 202 described with reference to FIGS. 7 and 8 is replaced with an etching groove reflecting mirror 203.

  The etching groove reflecting mirror 203 can be formed by dry etching with the quartz optical waveguide element substrate 101d tilted. The quartz optical waveguide 113 and the silicon optical waveguide 127 can be coupled with higher optical coupling efficiency than when the prism reflecting mirror 202 is used.

  That is, when the prism reflector 202 is used, a free space region of the prism reflector mounting recess 201 in which the optical waveguide structure is not formed is formed between the quartz optical waveguide 113 and the silicon optical waveguide 127. While the mode field diameter is widened and it is difficult to obtain high optical coupling efficiency, when the etching groove reflector 203 is used, a free space region does not occur and high optical coupling efficiency is easily obtained.

  Next, Example 3 will be described with reference to FIG. FIG. 11 is an example of a top view of the main part of the optical transmission module described in the third embodiment. Here, the principal part sectional view of the optical transmission module of Example 3 is the same as the principal part sectional view shown in FIG. The optical transmission module shown in FIG. 11 includes a quartz optical waveguide element substrate 101e, a convex lens 103, a reflecting mirror 104, an optical fiber mounting V-groove 107, a quartz optical waveguide 113, and a silicon optical waveguide 127.

  2 differs from the optical transmission module shown in FIG. 2 in that the optical multiplexer 114 is not formed, a plurality of optical fiber mounting V-grooves 107 are formed, and the number of convex lenses 103 is V. There are fewer points than the number of grooves 107 (one in the example shown in FIG. 11). The optical transmission module of Example 3 is suitable for an optical module for parallel transmission.

  Since an optical module for parallel transmission does not require a wavelength multiplexer, it is possible to directly mount an optical fiber on the optical circuit element. The optical coupling efficiency can be increased. This is because it is difficult to obtain high optical coupling efficiency because the difference in mode field diameter is generally large between the silicon optical waveguide 127 and the optical fiber, whereas the light from the silicon optical waveguide 127 is transmitted to the quartz optical waveguide 113. This is because the difference in mode field diameter can be reduced by coupling once and then coupling to the optical fiber.

  Other features of the optical transmission module according to the third embodiment are the same as those of the optical transmission module described in the first embodiment. That is, in the optical transmission module of Example 3, the convex lens 103 is formed on the quartz optical waveguide element substrate 101e, so that the number of components can be reduced, thereby reducing the cost and reducing the module size.

  Further, since the quartz optical waveguide device substrate 101e and the silicon optical waveguide device substrate 108 are stacked and mounted so that the surfaces on which the circuit layers are formed face each other, mounting tolerance is wide, and the convex lens 103 and the quartz optical waveguide device are wide. Are integrated so that high-precision alignment is required only once. In other words, if only the alignment of the quartz optical waveguide element and the optical circuit is performed, the position of the convex lens 103 can be adjusted to the desired position of the optical circuit with high accuracy.

  In the optical transmission module of the third embodiment, the description of the silicon optical waveguide layer that constitutes the silicon optical waveguide 127 is omitted. However, a branch optical waveguide for branching light is provided in the silicon optical waveguide layer, and each light By independently modulating the signals, it is possible to perform parallel transmission in which signals of a plurality of channels are simultaneously transmitted. In parallel transmission, the module can be increased in capacity as in the case of wavelength multiplexing.

  In the example of FIG. 11, the example in which the reflecting mirror 104 is provided on the end surface of the quartz optical waveguide element substrate 101e is shown, but the present invention is not limited to this, and the prism reflecting mirror 202 described with reference to FIGS. The structure which provides the etching groove | channel reflecting mirror 203 may be sufficient.

  Next, Example 4 will be described with reference to FIGS. FIG. 12 is an example of a top view of the main part of the optical transmission module described in the fourth embodiment, and FIG. 13 is an example of a cross-sectional view of the main part. As in FIGS. 1 and 2, those that cannot be identified by one of the top view and the cross-sectional view of the main part are shown on the other side.

  12 and 13 includes a quartz optical waveguide element substrate 101f, a quartz optical waveguide layer 102, a convex lens 103, a reflecting mirror 104, a quartz optical waveguide element optical coupling portion 105, a silicon optical waveguide element substrate 108, and a silicon optical waveguide. Layer 109, silicon optical waveguide device optical coupling portion (input side) 110, silicon optical waveguide device optical coupling portion (output side) 111, quartz optical waveguide 113, silicon optical waveguide 127, quartz optical waveguide optical coupling portion 401, multi-core fiber 402 That is, it includes a multi-core optical fiber.

  The difference from the optical transmission module of the third embodiment is that the optical fiber mounting V-groove 107 is not formed, and the optical coupling between the quartz optical waveguide 113 and the multi-core fiber 402 is not on the end face of the quartz optical waveguide 113 but on the surface. It is a point to do. The optical transmission module of Example 4 is suitable for a parallel transmission optical module, and particularly suitable for a parallel transmission optical module using a multi-core fiber.

  As described in the third embodiment, since the wavelength multiplexer is unnecessary in the parallel transmission optical module, an optical fiber can be directly mounted on the optical circuit element. By doing so, the optical coupling efficiency with the optical fiber can be increased. This is because it is difficult to obtain high optical coupling efficiency because the difference in mode field diameter is generally large between the silicon optical waveguide 127 and the optical fiber, whereas the light from the silicon optical waveguide 127 is transmitted to the quartz optical waveguide 113. This is because the difference in mode field diameter can be reduced by coupling once and then coupling to the optical fiber.

  Other features of the optical transmission module according to the fourth embodiment are the same as those of the optical module described in the first embodiment. That is, in the optical transmission module of Example 4, the convex lens 103 is formed on the quartz optical waveguide device substrate 101f, so that the number of components can be reduced, thereby reducing the cost and reducing the module size.

  Further, since the quartz optical waveguide device substrate 101f and the silicon optical waveguide device substrate 108 are stacked and mounted so that the surfaces on which the circuit layers are formed face each other, mounting tolerance is wide, and the convex lens 103 and the quartz optical waveguide device are wide. Are integrated so that high-precision alignment is required only once. In other words, if only the alignment of the quartz optical waveguide element and the optical circuit is performed, the position of the convex lens 103 can be adjusted to the desired position of the optical circuit with high accuracy.

  In the optical transmission module using the multi-core fiber 402 as in the optical transmission module of the fourth embodiment, the number of the multi-core fibers 402 is one. Can be miniaturized.

  Next, Example 5 will be described with reference to FIGS. FIG. 14 is a cross-sectional view of a main part of the optical transceiver module described in the fifth embodiment, in particular, a cross-sectional view of a main part on the transmission side, and FIG. FIGS. 14 and 15 are examples of optical transmission / reception modules based on the optical transmission modules shown in FIGS. 1 to 6, but the optical transmission / reception module of the fifth embodiment is not limited to this, and FIG. 7 to FIG. 14 may be included.

  14 and 15 includes a quartz optical waveguide element substrate 101g, a quartz optical waveguide layer 102, a convex lens 103, a reflecting mirror 104, a quartz optical waveguide element optical coupling portion 105, a quartz optical waveguide end face 106, and an optical fiber mounting. V-groove 107, silicon optical waveguide element substrate 108, silicon optical waveguide layer 109, silicon optical waveguide element optical coupling part (input side) 110, silicon optical waveguide element optical coupling part (output side) 111, module substrate 501, lens integrated semiconductor A laser 502, a temperature regulator 503, and a module housing 507 are included.

  Since it cannot be identified in FIG. 14, the optical transceiver module includes quartz optical waveguides 113a, 113b, 113c, 113d in the quartz optical waveguide layer 102, and silicon optical waveguides 127b, 127c, in the silicon optical waveguide layer 109, as shown in FIG. 127d and an alignment silicon optical waveguide 127a, an optical multiplexer 114 and an optical demultiplexer 508, and a transmission drive circuit 504a and a reception drive circuit 504b.

  Further, a spacer substrate 506 may be provided in a space where the silicon optical waveguide device substrate 108 is not provided between the quartz optical waveguide device substrate 101g and the module substrate 501 of the optical transceiver module shown in FIG. As shown in FIG. 15, a transmission optical fiber 505a and a reception optical fiber 505b are connected to the optical transceiver module, and these may be single mode optical fibers.

  The transmission drive circuit 504a is for driving the optical modulator formed on the silicon optical waveguide layer 109 located below the transmission drive circuit 504a in FIG. 15, and the reception drive circuit 504b is: This is for driving a light receiver formed on the silicon optical waveguide layer 109 located under the receiving drive circuit 504b. The temperature adjuster 503 is used to keep the temperature of the lens integrated semiconductor laser 502 constant.

  The optical transceiver module according to the fifth embodiment can transmit or receive an optical signal modulated at high speed. Hereinafter, transmission of an optical signal will be described in more detail. Non-modulated light (continuous light) is emitted from a lens integrated semiconductor laser 502 in which semiconductor lasers each emitting light having different wavelengths are arrayed, and the emitted light is collected by a convex lens 103 to be coupled to a silicon optical waveguide device. Part (input side) 110.

  The input continuous light passes through the silicon optical waveguide 127b formed in the silicon optical waveguide layer 109, the optical modulator, and the silicon optical waveguide 127c, and from the silicon optical waveguide element optical coupling part (output side) 111 to the quartz optical waveguide element. The light is output to the reflecting mirror 104 of the optical coupling unit 105. Here, continuous light is converted into modulated light by driving the optical modulator with the transmission drive circuit 504a.

  A plurality of modulated lights having different wavelengths are coupled to the respective quartz optical waveguides 113 c formed on the quartz optical waveguide layer 102 via the quartz optical waveguide element optical coupling unit 105. The respective optical waveguides are combined into one optical waveguide by the optical multiplexer 114 and emitted from the transmission optical fiber 505a. In this way, a plurality of modulated lights having different wavelengths can be transmitted through one optical fiber.

  Next, the optical signal receiving function will be described. A plurality of modulated lights having different wavelengths input to the receiving optical fiber 505b are branched into different quartz optical waveguides 113d for each wavelength in the optical demultiplexer 508. Each branched modulated light is reflected to the silicon optical waveguide layer 109 by the reflecting mirror 104 of the quartz optical waveguide device optical coupling part 105.

  The reflected modulated light is input to the light receiver via the silicon optical waveguide 127d formed on the silicon optical waveguide layer 109. Here, the light receiving device is driven by the receiving drive circuit 504b to convert the modulated light into an electrical signal. In this way, a plurality of modulated lights having different wavelengths can be received.

  The characteristics of the transmission / reception module of the fifth embodiment are the same as those of the transmission module described in the first embodiment. That is, since the convex lens 103 is formed on the quartz optical waveguide element substrate 101g, it is possible to reduce the number of components, thereby reducing the cost and downsizing the module size, and the quartz optical waveguide element substrate 101g and the silicon optical waveguide element substrate. 108 are stacked and mounted so that the surfaces on which the circuit layers are formed face each other, and therefore, the mounting tolerance is wide.

  Furthermore, since the convex lens 103 and the wavelength multiplexer / demultiplexer or the quartz optical waveguide element are integrated, high-precision alignment is required only once. In other words, if only the wavelength multiplexer / demultiplexer or the alignment of the quartz optical waveguide element and the optical circuit is performed, the position of the convex lens 103 can be adjusted to the desired position of the optical circuit with high accuracy.

  The present invention is not limited to the embodiments described in the above examples, and various modifications can be made. For example, the configuration described in the embodiment may be replaced with substantially the same configuration. Further, a part of each embodiment may be replaced with a part of another embodiment. In addition, the expression formed in the above description represents the state and shape of an object as a result of formation.

DESCRIPTION OF SYMBOLS 101 ... Silica optical waveguide element substrate 102 ... Silica optical waveguide layer 103 ... Convex lens 104 ... Reflective mirror 105 ... Quartz optical waveguide element optical coupling part 108 ... Silicon optical waveguide element substrate 109 ... Silicon optical waveguide element 110 ... Silicon optical waveguide element optical coupling (Input side)
111 ... Silicon optical waveguide device optical coupling part (output side)
113 ... Quartz optical waveguide 122 ... Diffraction grating 127 ... Silicon optical waveguide

Claims (15)

An optical transceiver module configured by surface contact between a first substrate and a second substrate,
The first substrate is
On the first surface of the first substrate, including a first light incident part and a first light emitting part,
The second substrate is
The second substrate includes a second light incident portion, a second light emitting portion, and a third light incident portion on the second surface of the second substrate, and is opposite to the second surface in the second substrate. A lens for collecting the input light on the third surface of
The first surface and the second surface are opposed to and in contact with each other;
The lens and the first light incident part are optically connected,
The first light incident part and the first light emitting part are optically connected,
The first light emitting part and the second light incident part are optically connected,
The second light incident part and the second light emitting part are optically connected, and light is transmitted from the second light emitting part,
An optical transceiver module, wherein light is received by the third light incident portion. The optical transceiver module according to claim 1,
The first substrate is a silicon substrate;
The optical transceiver module, wherein the second substrate is a quartz substrate. The optical transceiver module according to claim 1,
The first substrate includes a fourth light incident portion on the first surface,
The second substrate includes a third light emitting unit on the second surface,
The third light incident part and the third light emitting part are optically connected,
The optical transceiver module, wherein the third light emitting unit and the fourth light incident unit are optically connected. The optical transceiver module according to claim 3,
The second substrate includes a plurality of the second light incident portions and an optical multiplexer,
The plurality of second light incident portions are connected to a plurality of first optical waveguides, respectively, the plurality of first optical waveguides are connected to the optical multiplexer, and the optical multiplexer is connected to the second light output. And a second optical waveguide,
The optical transceiver module multiplexes light incident from a plurality of the first optical waveguides and outputs the combined light to the second optical waveguide. The optical transceiver module according to claim 4,
The second substrate includes a plurality of the third light emitting portions and an optical demultiplexer,
The third light incident portion is connected to the optical demultiplexer by a third optical waveguide, the optical demultiplexer is connected to a plurality of fourth optical waveguides, and the plurality of third light emitting portions are Respectively connected to a plurality of the fourth optical waveguides;
The optical demultiplexer demultiplexes light incident from the third optical waveguide and emits the light to each of the plurality of fourth optical waveguides. The optical transceiver module according to claim 5,
The optical transceiver module, wherein the second substrate has a groove for optically connecting the second light emitting section and the single mode optical fiber. The optical transceiver module according to claim 3,
The second substrate includes a plurality of the second light incident portions and a plurality of the second light emission portions,
The plurality of second light incident portions are respectively connected to a plurality of fifth optical waveguides, and the plurality of fifth light waveguides are respectively connected to the plurality of second light emitting portions. Optical transceiver module. The optical transceiver module according to claim 7,
The optical transceiver module, wherein the second substrate has a surface on the second surface where a plurality of the second light emitting portions and a multi-core optical fiber are optically connected. The optical transceiver module according to claim 3,
The optical transmission / reception module, wherein the first light incident part includes a diffraction grating region that changes an axial direction of light incident from the lens by approximately 90 degrees. The optical transceiver module according to claim 3,
The optical transmission / reception module, wherein the second light incident part includes a reflecting mirror that changes an axial direction of light incident from the first light emitting part by approximately 90 degrees. The optical transceiver module according to claim 3,
The optical transmission / reception module, wherein the first light emitting unit includes a diffraction grating region that changes an axial direction of light incident from the first light incident unit by approximately 90 degrees. The optical transceiver module according to claim 3,
The first substrate includes a plurality of the first light emitting portions,
The plurality of first light emitting sections are connected to a plurality of sixth optical waveguides, respectively, and the plurality of sixth optical waveguides are connected to the first light incident sections. . The optical transceiver module according to claim 3,
The first substrate includes a plurality of the first light incident portions and a plurality of the first light emission portions,
The second substrate includes a plurality of the lenses,
The plurality of lenses and the plurality of first light incident portions are respectively optically connected,
The plurality of first light incident portions are respectively connected to a plurality of seventh optical waveguides, and the plurality of seventh optical waveguides are connected to the plurality of first light emitting portions. Transmit / receive module. The optical transceiver module according to claim 3,
The first substrate includes a fifth light emitting portion and a sixth light incident portion on the first surface,
The second substrate includes a fourth light emitting part, a fifth light incident part, a sixth light emitting part, and a seventh light incident part on the second surface,
The fifth light emitting portion and the sixth light incident portion are connected by an eighth optical waveguide,
The fourth light emitting part and the fifth light incident part are connected by a ninth optical waveguide,
The sixth light emitting part and the seventh light incident part are connected by a tenth optical waveguide,
The fourth light emitting part and the sixth light incident part are optically connected, and the fifth light emitting part and the seventh light incident part are optically connected,
An optical transceiver module, wherein light is input from the fifth light incident portion and light is output from the sixth light emitting portion. A method of adjusting an optical transceiver module configured by surface contact between a first substrate and a second substrate,
The first substrate is
On the first surface of the first substrate, including a first light incident part, a first light emitting part, a fifth light emitting part, and a sixth light incident part,
The second substrate is
On the second surface of the second substrate, a second light incident part, a second light emitting part for transmitting light, a third light incident part for receiving light, and a fourth light emitting part. On the third surface opposite to the second surface of the second substrate, and a fifth light incident portion, a sixth light emitting portion, and a seventh light incident portion. Including a lens that collects the input light,
The first surface and the second surface are opposed to and in contact with each other;
The first light incident part and the first light emitting part are connected by a seventh optical waveguide,
The second light incident part and the second light emitting part are connected by a fifth optical waveguide,
The fifth light emitting portion and the sixth light incident portion are connected by an eighth optical waveguide,
The fourth light emitting part and the fifth light incident part are connected by a ninth optical waveguide,
For the optical transceiver module in which the sixth light emitting section and the seventh light incident section are connected by a tenth optical waveguide,
Input light to the fifth light incident part;
Monitoring the light output from the sixth light emitting section;
A method for adjusting an optical transceiver module, comprising adjusting a relative positional relationship between the first substrate and the second substrate.

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