JP2018092016A - Optical component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical component capable of suppressing degradation in optical characteristics and/or reliability of a light beam which is input/output with a space optical system due to influences of heat from a heating part such as a heat phase shifter.SOLUTION: The optical component includes: an optical waveguide forming layer 102 which is formed on a principal face of a base plate 101; a heating part 103 which is disposed on a part of the optical waveguide forming layer 102; a space light beam input/output part 104 formed at one end of the optical waveguide forming layer 102; and a groove 105 formed on the rear face of the base plate 101 between the space light beam input/output part 104 and the heating part 103.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical component including a planar optical waveguide circuit that includes a heat generating portion and inputs / outputs light to / from a spatial optical system.

  In order to cope with an increase in the capacity of information communication traffic, wavelength division multiplexing transmission is realized in a communication network using optical fibers. In addition, many optical communication devices compatible with wavelength division multiplexing have been put into practical use, but in order to cope with further increases in capacity in the future, further enhancement of functionality is desired.

  As such an optical communication device, there is a planar optical waveguide. Planar optical waveguides are widely used because optical multiplexing / demultiplexing functions, branching functions, switching functions, and the like can be mounted with high accuracy. In particular, quartz-based planar lightwave circuits (PLCs) made of quartz glass are excellent in coupling with optical fibers and have high material reliability, so splitters, wavelength multiplexers / demultiplexers, optical switches, etc. It is applied to a wide variety of functional elements for optical communication. In addition, an optical functional element using an optical waveguide made of a semiconductor material or an Si optical waveguide having silicon as a core has been widely applied because of its excellent integration with a light emitting / receiving element and miniaturization.

  In particular, in an optical switch, a reconfigurable optical add / drop multiplexer (ROADM) system is introduced. In the conventional optical switch, a method of switching a path using an electrical switch after converting a transmitted optical signal into an electrical signal has been the mainstream. In contrast, the ROADM system takes advantage of the characteristics of an optical signal that is high-speed and wide-band, and performs add / drop using the optical switch or the like as it is.

  In the ROADM system, a wavelength division multiplexing network using optical fibers is used as a ring type, and an optical signal is added and dropped at each node of the ring network. Has been done. As a device necessary for this ROADM system, a directional coupler or a Mach-Zehnder type waveguide using a directional coupler and an optical waveguide type optical switch for switching between ports using a phase shifter or the like are known.

  As a typical configuration, there is a switching element using a heater (electric heater) (see Patent Document 1). This switching element forms a heater in the optical waveguide in the Mach-Zehnder optical circuit, changes the refractive index of the optical waveguide by applying heat to the heater, changes the phase, and turns on and off the output light and the light Intensity adjustment and phase modulation are performed. This technique using a heater is also called a thermal phase shifter.

  In addition, a phase shifter based on an electro-optic effect or a plasma effect caused by carrier injection is also known. All of the phase shifters are arranged in the vicinity of the optical waveguide, and electric wiring for electrically controlling the phase shifter is formed on the optical waveguide. In addition, as a semiconductor PLC, an optical waveguide type optical switch using a semiconductor optical amplification effect and electric field absorption that electrically controls optical absorption of the optical waveguide is also known.

  In addition to the optical waveguide type optical switch described above, a wavelength selective switch (WSS) module capable of switching wavelength multiplexed signals in units of wavelength channels is also known as a more sophisticated optical switch. . The WSS module includes an input / output system composed of an optical fiber, a spatial optical system composed of a diffraction grating and a lens, and a spatial light switching element such as a MEMS or a phase modulation element such as LCOS (Liquid Crystal On Silicon). .

  In recent years, a high-performance WSS module in which a lens function, a diffraction grating function, and the like are integrated in the optical fiber input / output system using the above-described planar optical waveguide made of silica-based PLC has also been proposed (Non-patent Document 1). reference). In this module, an optical fiber is connected to one of the optical waveguides, and the beam diameter and phase are controlled by light input / output from the optical fiber passing through the optical waveguide. The light beam whose beam diameter and phase are controlled is input / output from one of the optical waveguides to the spatial optical system and passes through a lens or the like. Further, as described in Non-Patent Document 1, an optical waveguide type optical switch in which a thermal phase shifter is arranged in an optical waveguide is integrated to form an input / output system, and a spatial optical system and a phase modulation element used for WSS, etc. Applications such as combination and use for high-function add / drop switches for ROADMs have been reported.

  In addition to the optical switch, as described in Patent Document 1, an application in which a planar optical waveguide and a light emitting / receiving element such as a laser or a photodiode are integrated via a spatial optical system has been reported, Fusion of planar optical waveguides and spatial optical systems is progressing.

JP 2007-078861 A

Y. Ikuma et al., "8 × 24 Wavelength Selective Switch for Low-loss Transponder Aggregator", Optical Fiber Communications Conference and Exhibition, 15216151, pp. 22-26, 2015.

  When the above-described planar optical waveguide is used as a spatial optical system, a light beam is input and output between the planar optical waveguide and the spatial optical system. It is important that the position, emission angle, beam shape, and the like are stable. For this reason, generally, the reliability is ensured by fixing the input / output portion of the light beam in the planar optical waveguide to a package or the like using an adhesive or solder.

  However, as described in Non-Patent Document 1, when a thermal phase shifter is combined with a planar optical waveguide to form an input / output system, problems arise in the stability of the light beam emission position, emission angle, and beam shape. In the technique using the thermal phase shifter, the generated heat is applied to the beam input / output unit. For this reason, the following problems occur. First, the optical waveguide chip itself is thermally expanded, and as a result, the emission position of the light beam is shifted. Secondly, stress accompanying thermal change is applied to the fixing part using an adhesive or the like, and the reliability of the fixing part deteriorates. Third, the refractive index of the optical waveguide formed in the input / output unit changes due to heat or the like, the light interference state changes in the input / output unit, and the quality of the light beam changes.

  Due to the problems described above, there is a problem that the optical characteristics and reliability of the entire system deteriorates without being matched with the spatial optical system.

  The present invention has been made to solve the above-described problems, and optical characteristics of a light beam input / output to / from a spatial optical system due to the influence of heat from a heat generating portion such as a thermal phase shifter. The purpose is to prevent deterioration of reliability.

  An optical component according to the present invention includes an optical waveguide forming layer including an optical waveguide formed on a main surface of a substrate, a heat generating portion that generates heat disposed in a part of the optical waveguide forming layer, and an optical waveguide forming layer. A spatial light beam input / output unit, a spatial light beam input / output unit, and a heat generating unit that are provided at one end and emit a light beam into the space from the optical waveguide forming layer and make the light beam from the space enter the optical waveguide forming layer And a groove formed on the back surface of the substrate.

  The optical component may include a reinforcing member made of a material having a lower thermal conductivity than the substrate and filled in the groove.

  The optical component may include a heat dissipation component connected to the back surface of the substrate in the region where the heat generating portion is formed.

  The optical component may include a holding structure that holds the substrate by connecting to the back surface of the substrate on the side where the spatial light beam input / output unit is disposed from the groove.

  In the optical component, the heat generating portion is a thin film heater that heats a part of the optical waveguide of the optical waveguide forming layer. The heat generating part is a semiconductor laser.

  In the optical component described above, the substrate may be made of any of single crystal Si, polycrystalline Si, amorphous Si, tungsten, tungsten silicide, quartz, lithium tantalate, aluminum nitride, indium phosphide, and quartz.

  As described above, according to the present invention, since the groove is provided on the back surface of the substrate between the spatial light beam input / output unit and the heat generating unit, the space due to the influence of heat from the heat generating unit such as a thermal phase shifter is provided. An excellent effect is obtained that deterioration of optical characteristics and reliability of a light beam input / output to / from the optical system can be suppressed.

FIG. 1 is a configuration diagram showing the configuration of the optical component according to Embodiment 1 of the present invention. FIG. 2 is a plan view showing a partial configuration of the optical component according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view showing a partial configuration of the optical component according to Embodiment 1 of the present invention. FIG. 4A is a configuration diagram showing a configuration of a conventional optical component. FIG. 4B is a configuration diagram illustrating a configuration of a conventional optical component. FIG. 4C is a configuration diagram illustrating a configuration of a conventional optical component. FIG. 5 is a configuration diagram showing another configuration of the optical component according to Embodiment 1 of the present invention. FIG. 6 is a plan view showing a configuration example of the optical component according to Embodiment 1 of the present invention. FIG. 7 is a configuration diagram showing the configuration of the optical component according to Embodiment 2 of the present invention. FIG. 8 is a configuration diagram showing the configuration of the optical component according to Embodiment 3 of the present invention. FIG. 9 is a block diagram showing the configuration of the optical component according to Embodiment 4 of the present invention. FIG. 10 is a configuration diagram showing the configuration of the optical component according to Embodiment 5 of the present invention. FIG. 11 is a block diagram showing the configuration of the optical component according to Embodiment 6 of the present invention. FIG. 12 is a block diagram showing the configuration of the optical component according to Embodiment 7 of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
First, Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a configuration diagram showing the configuration of the optical component according to Embodiment 1 of the present invention. FIG. 1 schematically shows a cross section. This optical component includes an optical waveguide forming layer 102 formed on the main surface of the substrate 101. The optical waveguide forming layer 102 includes, for example, a plurality of optical waveguides to form an optical circuit. For example, a planar lightwave circuit (PLC) is constituted by an optical waveguide forming layer 102 made of glass (silicon oxide) on a substrate 101 made of single crystal silicon (Si).

  The optical component also includes a heat generating portion 103 that emits heat and is disposed in a part of the optical waveguide forming layer 102. This optical component also includes a spatial light beam input / output unit 104 provided at one end of the optical waveguide forming layer 102. The spatial light beam input / output unit 104 is a light incident / exit end portion of the optical waveguide provided in the optical waveguide forming layer 102. The spatial light beam input / output unit 104 emits a light beam to the space 121 from the end of the optical waveguide on one end side of the optical waveguide forming layer 102. Further, the light beam from the space 121 is incident on the end portion of the optical waveguide on one end side of the optical waveguide forming layer 102 by the spatial light beam input / output unit 104.

  For example, the spatial light beam input / output unit 104 is applied to a WSS or the like through a spatial optical system such as a lens or a phase modulation element (not shown), and is optically connected to a light receiving unit (not shown) such as a photodiode. By this, it is configured to be applied to an optical receiver. The spatial light beam input / output unit 104 for inputting / outputting a light beam may use a tapered optical waveguide or the like that gradually changes the core diameter of the optical waveguide forming layer 102 to expand the beam diameter as necessary. Alternatively, as described in Non-Patent Document 1, an array optical waveguide, a slab optical waveguide, or the like may be combined with the spatial light beam input / output unit 104 to have a lens function or a diffraction grating function.

  Here, for example, the optical waveguide forming layer 102 includes a first core 111a and a second core 111b as shown in the plan view of FIG. The first core 111a and the second core 111b include two directional couplers 112 and constitute a Mach-Zehnder interferometer. As shown in the partial cross-sectional view of FIG. 3, the first core 111 a and the second core 111 b are embedded in the cladding layer 113. Each core constitutes an optical waveguide.

  Further, in the heat generating portion 103, a thin film heater 114a is formed on the cladding layer 113 above the first core 111a. A wiring 115a is connected to the thin film heater 114a so that a current can be applied. Similarly, in the heat generating portion 103, a thin film heater 114b is formed on the clad layer 113 on the second core 111b. A wiring 115b is connected to the thin film heater 114b so that a current can be applied. The thin film heater 114a and the thin film heater 114b generate heat by applying the current. These constitute a thermal phase shifter. In the first embodiment, as described above, the thin film heater that heats a part of one of the optical waveguides of the optical waveguide forming layer 102 serves as the heat generating portion 103.

  Each wiring is routed on the optical component, connected to a pad (not shown) provided on the optical component, and the pad is electrically connected to the outside using wire bonding or the like. In the example described above, an optical circuit such as a Mach-Zehnder type optical switch or an optical variable attenuator is formed by two thin film heaters. By applying heat to the core with a thin film heater, the refractive index of the core changes. As a result, it is possible to control the interference condition in one directional coupler. By utilizing this, it is used as an optical switch or an optical variable attenuator. Moreover, by connecting these configurations continuously, it is possible to form an arbitrary 1 × M switch (M is an integer). In this example, the thin film heater is formed on the two optical waveguides of the Mach-Zehnder, but may be formed on only one of them.

  In addition to the above configuration, the optical component in the first embodiment includes a groove 105 formed on the back surface of the substrate 101 between the spatial light beam input / output unit 104 and the heat generating unit 103. The groove portion 105 is formed on the back surface of the substrate 101 so as to partition the arrangement region of the spatial light beam input / output unit 104 and the arrangement region of the heat generating unit 103. As shown in FIG. 1, the groove 105 may be in a state in which a part of the substrate is left slightly on the optical waveguide forming layer 102 side. Further, the groove 105 may be formed through the substrate 101. However, the groove 105 is formed so as to penetrate the substrate 101, so that the highest heat insulating effect can be obtained as a heat insulating structure described later.

  In the first embodiment, the optical input / output unit 106 provided at the other end of the optical waveguide forming layer 102 is provided. An optical fiber 107 is optically connected to the optical input / output unit 106. The optical fiber 107 is optically connected to an optical waveguide provided in the light input / output unit 106. The optical fiber 107 is fixed to the substrate 101 and the auxiliary component 109 attached to the substrate 101 by a fixing component 108. The fixed component 108 is bonded to the side surface of the substrate 101 and the auxiliary component 109 with an adhesive layer 110 made of an adhesive. The light input / output unit 106 and the optical fiber 107 may be connected via a spatial optical system.

  Here, an operation example of the optical component in Embodiment 1 will be described. For example, when the thin film heater 114a is driven, the first core 111a in this portion has a temperature difference of about 10 to 50 ° C. as compared with the second core 111b that is not driving the thin film heater 114b. The heat from the thin film heater 114a is transmitted approximately isotropically to the cladding layer 113 around the first core 111a. The heat conducted in this way is conducted to the clad layer 113 below the first core 111 a and then further conducted to the substrate 101.

  Here, the thermal conductivity of the substrate 101 made of single crystal Si is about two orders of magnitude larger than the thermal conductivity of glass. For this reason, in the substrate 101, heat conduction proceeds relatively quickly, and heat is immediately transmitted to the entire substrate 101. As a result, in the time until the heat reaches the substrate 101 from the thin film heater 114a, the heat is transmitted to each core and the clad layer 113 approximately isotropically. However, once heat reaches the substrate 101, the heat flow becomes dominant in the substrate 101, which means that heat conduction in each core portion and the clad layer 113 is not performed except in a part of the region.

  Moreover, since the wiring made of a metal such as Au has a very high thermal conductivity, the heat of the heater is conducted immediately. For this reason, the same phenomenon as described above occurs immediately under the wiring.

  In the optical switch, since a plurality of heaters are arranged and a large number of wirings are formed, heat from the vicinity of the heaters and wirings is also transmitted to the substrate. As a result, in the configuration without the groove shown in FIG. 4A, heat is transferred to the spatial light beam input / output unit 104 via the substrate 101. For this reason, for example, the optical component is thermally expanded by heat generated every time the optical switch operation is performed, and the emission position of the light beam changes. In addition, stress due to thermal expansion is applied to the portion for fixing the optical fiber 107 and the like, and the reliability of the fixing portion is reduced. Alternatively, the refractive index of the optical waveguide forming layer 102 in the spatial light beam input / output unit 104 changes due to heat, the light interference state in the spatial light beam input / output unit 104 changes, and the quality of the light beam changes. As a result, there is a problem that the optical characteristics and the reliability of the entire system are deteriorated without matching with the spatial optical system.

  Since the number of elements and temperature for driving the thin film heater are dynamically different for each function such as switch switching, the heat changes every time the driving is different, and the above-mentioned problem occurs every time the driving is performed. .

  In response to the above-described problem, according to the first embodiment of the present invention, since the groove portion 105 having a heat insulating structure is provided, the heat generated in the heat generating portion 103 and reaching the substrate 101 passes through the substrate in the groove portion 105. The conduction is blocked and it is difficult to transmit to the spatial light beam input / output unit 104 side of the substrate 101. For this reason, most of the heat generated in the heat generating part 103 is transmitted to the heat generating part side of the substrate 101 and is transmitted to the space.

  If the distance between the heat generating portion 103 and the groove portion 105 is larger than the thickness of the optical waveguide forming layer 102 and is more than a certain distance, most of the heat is transferred to the substrate 101 in the region where the heat generating portion 103 is disposed. It is transmitted and radiated from the exposed surface (back surface, etc.). As a result, in the first embodiment, the time until the heat from the heat generating unit 103 is transmitted to the spatial light beam input / output unit 104 is relatively very slow. As a result, the above-described problem can be suppressed.

  Furthermore, by dissipating a heat dissipating component that causes heat transfer more efficiently to the back surface of the substrate 101 in the region where the heat generating portion 103 is formed via heat conductive grease or the like, almost all heat is dissipated. It will be transmitted to the parts. As a result, the heat from the heat generating unit 103 is hardly transmitted to the spatial light beam input / output unit 104, and the above-described problem can be more effectively suppressed.

  Next, differences from the conventional heat insulation structure will be described. Conventionally, the structure shown in FIGS. 4B and 4C is known as a technique for thermally insulating a heater disposed on an optical waveguide. 4B and 4C show cross sections perpendicular to the waveguide direction. These structures are fundamentally different from the present structure because they suppress heat dissipation and are used to efficiently apply heat from the heater to the core directly below. For example, in the configuration shown in FIG. 14B, no substrate is provided immediately below the heater. For this reason, the heat generated from the heater is not easily transmitted to the substrate, and the heat is efficiently applied to the core directly under the heater. As a result, the refractive index of the optical waveguide can be changed by the core directly under the heater with lower power consumption.

  In the configuration shown in FIG. 14C, the optical waveguide of the core where the heater is disposed is separated from the optical waveguide of the other core. For this reason, the heat from the heater is not transmitted to the substrate via another optical waveguide, and the heat is efficiently applied to the core directly under the heater. As a result, also in this configuration, it is possible to change the refractive index of the optical waveguide by the core directly under the heater with lower power consumption.

  In these technologies, heat is transmitted to the substrate side as a result, so that the heat is conducted to the entire optical component. Further, since the separated structure is along the waveguide direction, heat is conducted to the entire chip through the wiring portion and the like.

  On the other hand, the present invention divides the substrate in a direction perpendicular to or different from the traveling direction of the core, and has a difference that the intended purpose is fundamentally different.

  Next, the manufacturing method of the optical component in Embodiment 1 is demonstrated easily. For example, a well-known SOI (Silicon on Insulator) substrate is used, and the surface Si layer is patterned by a known photolithography technique and etching technique to form a core layer constituting an optical waveguide (optical circuit). Next, for example, by a well-known deposition method such as a plasma CVD method, Si oxide is deposited to form a cladding layer, and an optical waveguide is formed. Next, a thin film heater is formed at a predetermined location, and wirings connected to the thin film heater are formed.

  Regarding the method of forming the optical waveguide, in addition to the above, a glass layer serving as an underclad is formed on a Si substrate by using a flame deposition method or the like, and the refractive index is higher than that of the clad by photolithography technology and etching technology. A method of forming a core-embedded optical waveguide by depositing a glass layer again after embedding a high core glass material may be used.

  As described above, after the optical waveguide forming layer 102 and the heat generating portion 103 are formed on the substrate 101, the groove portion 105 is formed on the back surface of the substrate 101. For example, the groove 105 can be formed by forming a mask pattern having an opening in the groove 105 and selectively removing the back surface of the substrate 101 by etching using the mask pattern. As an etching method, either a deep RIE method or wet etching can be used. Alternatively, the groove 105 may be formed by making a cut from the back surface of the substrate 101 using a dicing technique.

  The groove 105 has a rectangular cross section in the extending direction, but is not limited to this. As shown in FIG. 5, the cross section in the extending direction has a triangular shape, and the width becomes narrower as it approaches the optical waveguide forming layer 102. It is good also as the groove part 105a which becomes. For example, when selective etching is performed with an alkaline aqueous solution from the back surface of the substrate 101 made of single-crystal Si whose main surface has a plane orientation of (100) using the mask pattern, the tilt angle is about 55 degrees ( 111) is etched to expose the surface. Thereby, the groove part 105a of a cross-sectional triangle can be formed. Further, the groove 105a may be formed by dicing using an oblique blade.

  Also in this case, the groove 105 a may be in a state in which a part of the substrate is left slightly on the optical waveguide forming layer 102 side, or may be formed through the substrate 101. However, the groove 105a is also formed through the substrate 101, so that the highest heat insulating effect can be obtained as a heat insulating structure.

  In addition, the substrate 105 in the region where the heat generating portion 103 is formed and the substrate 101 provided with the spatial light beam input / output portion 104 may be thermally separated by the groove portion 105. For example, in the above-described example, as shown in FIG. 6A, a groove 105 extending linearly in a plan view may be formed, and in a plan view as shown in FIG. 6B. A U-shaped groove 205 may be formed.

  Further, as shown in FIG. 6C, in addition to the groove portion 205a between the region where the heat generating portion 103 is formed and the region where the spatial light beam input / output portion 104 is formed, the optical waveguide forming layer 102 is formed. A groove portion 205 b may be formed on the back surface of the substrate 101 between the other end side and the heat generating portion 103 so as to separate the formation region of the heat generating portion 103.

  In addition, a groove 205c that surrounds the region of the substrate 101 where the heat generating portion 103 is formed in a plan view may be formed. The spatial light beam input / output unit 104 is disposed outside the groove 205c.

[Embodiment 2]
Next, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 7 is a configuration diagram showing the configuration of the optical component according to Embodiment 2 of the present invention. FIG. 7 schematically shows a cross section. This optical component includes an optical waveguide forming layer 102 formed on the main surface of the substrate 101. Further, the optical component includes a heat generating portion 103 provided in a part of the optical waveguide forming layer 102. This optical component also includes a spatial light beam input / output unit 104 provided at one end of the optical waveguide forming layer 102.

  The optical component in the second embodiment includes a groove 105 formed on the back surface of the substrate 101 between the spatial light beam input / output unit 104 and the heat generating unit 103. The optical input / output unit 106 is provided at the other end of the optical waveguide forming layer 102. An optical fiber 107 is optically connected to the optical input / output unit 106. The optical fiber 107 is fixed to the substrate 101 and the auxiliary component 109 attached to the substrate 101 by a fixing component 108. The fixed component 108 is bonded to the side surface of the substrate 101 and the auxiliary component 109 with an adhesive layer 110 made of an adhesive.

  The configuration described above is the same as that of the first embodiment. The second embodiment includes a reinforcing member 301 that is made of a material having lower thermal conductivity than the substrate 101 and is filled in the groove 105. When the substrate 101 is made of single crystal Si, the reinforcing member 301 may be made of, for example, an epoxy resin, a silicone resin, an acrylic resin, or the like. As long as there is no mixture, these resins are suitable because the thermal conductivity is sufficiently lower than that of glass or Si and the Young's modulus is also small.

  According to the second embodiment, as in the first embodiment described above, the fluctuation of the light beam emission position to the space, the deterioration of the quality of the light beam, or the influence / deterioration of the heat application at the adhesive fixing portion can be suppressed. Become. Since the reinforcing member 301 has a low thermal conductivity, the heat conduction through the reinforcing member 301 is negligible. Furthermore, by connecting a heat dissipating component that causes heat transfer more efficiently to the substrate 101 via a thermal conductive grease or the like, almost all heat is transmitted to the heat dissipating component. As a result, the heat from the heat generating unit 103 is hardly transmitted to the spatial light beam input / output unit 104, and the above-described problem can be more effectively suppressed.

Furthermore, according to the second embodiment, since the groove portion 105 is filled with the reinforcing member 301, it is possible to prevent a decrease in mechanical strength and deformation in the groove portion 105 of the substrate 101. As a result, it is possible to prevent a decrease in mechanical strength and deformation of the optical waveguide forming layer 102 in this portion, and a more reliable optical component can be realized. Here, it is desirable that the reinforcing member 301 is made of a polymer resin and is formed by filling after forming the groove portion 105. In particular, it is preferable to form the reinforcing member 301 by using a thermosetting resin or a photo-curing resin and filling the groove 105 with these materials and then curing it by heating or light irradiation. The smaller the Young's modulus of the reinforcing member 301 is, the smaller the influence of the stress on the substrate 101 and the optical waveguide forming layer 102 is, and more specifically, the Young's modulus of the reinforcing member 301 is 1 × 10 at room temperature (25 ° C.). ^It is preferably about ⁹ Pa or less.

[Embodiment 3]
Next, Embodiment 3 of the present invention will be described with reference to FIG. FIG. 8 is a configuration diagram showing the configuration of the optical component according to Embodiment 3 of the present invention. FIG. 8 schematically shows a cross section. The optical component is provided on the optical waveguide forming layer 102 formed on the main surface of the substrate 101, the heat generating portion 103 disposed on a part of the optical waveguide forming layer 102, and one end of the optical waveguide forming layer 102. And a spatial light beam input / output unit 104.

  The optical component according to the third embodiment includes a groove 105 formed on the back surface of the substrate 101 between the spatial light beam input / output unit 104 and the heat generating unit 103. The optical component also includes an optical input / output unit 106 provided at the other end of the optical waveguide forming layer 102. An optical fiber 107 is optically connected to the optical input / output unit 106. The optical fiber 107 is fixed to the substrate 101 and the auxiliary component 109 attached to the substrate 101 by a fixing component 108. The fixed component 108 is bonded to the side surface of the substrate 101 and the auxiliary component 109 with an adhesive layer 110 made of an adhesive.

  The configuration described above is the same as that of the first embodiment. In addition to these, in the third embodiment, first, a heat sink (heat radiating component) 401 connected to the back surface of the substrate 101 in a region where the heat generating portion 103 is formed is provided. In the third embodiment, a holding structure 402 that holds the substrate 101 by connecting to the back surface of the substrate 101 on the side where the spatial light beam input / output unit 104 is disposed from the groove 105 is provided. The holding structure 402 is thermally separated from the heat sink 401.

  The heat sink 401 includes fins and a plurality of bars on the heat radiating surface, and is connected to the back surface of the substrate 101 by a heat conducting surface opposite to the heat radiating surface. It is preferable to increase the surface area by providing fins or the like so that heat transfer and radiant heat are increased. For example, the heat conductive surface of the heat sink 401 is bonded and fixed to the back surface of the substrate 101 with an adhesive layer 403 made of a heat transfer adhesive. The adhesive layer 403 may be composed of heat transfer grease, a film-type adhesive, or the like. Further, the adhesive layer 403 may be made of solder. Alternatively, a metal bump or the like may be used as the adhesive layer 403 and the heat sink 401 may be bonded to the back surface of the substrate 101. The heat sink 401 may be made of a metal having a thermal conductivity equal to or higher than that of the substrate 101, such as aluminum or copper.

  Further, a heat control heater, a heat control Peltier element, or the like may be provided between the heat sink 401 and the substrate 101.

  As described above, by providing the heat sink 401, the heat conducted to the substrate 101 is transmitted to the heat sink 401, and it is more difficult to transmit to the substrate 101 on the side where the spatial light beam input / output unit 104 is formed. .

  In addition, the holding structure 402 is bonded to the back surface of the substrate 101 on the side where the spatial light beam input / output unit 104 is disposed with respect to the groove portion 105 by an adhesive layer 404 made of solder or adhesive. The holding structure 402 is preferably the same as or integrated with a housing or a package for holding the optical component. The holding structure 402 may be made of a general-purpose metal such as SUS, or an alloy according to the use of a housing or a package as appropriate. Here, the material constituting the holding structure 402 preferably has a thermal expansion coefficient close to that of the substrate 101. For this reason, when the substrate 101 is made of Si, the holding structure 402 is preferably made of Kovar, Invar, or the like. The holding structure 402 may be made of an oxide such as glass, ceramic, low thermal expansion ceramic, or the like.

  By providing the holding structure 402, the optical component in Embodiment 3 has a structure fixed to the holding structure 402, and the positional deviation of the light beam emitted to the space can be suppressed with the holding structure 402 as a reference. Is possible. For example, the holding structure 402 can be connected to a lens, a phase modulation element, or a fixed portion of a photodiode disposed in the spatial optical system. With this configuration, the relative position between the spatial optical system and the optical component can be stabilized without being affected by the heat from the heat generating unit 103.

[Embodiment 4]
Next, Embodiment 4 of the present invention will be described with reference to FIG. FIG. 9 is a block diagram showing the configuration of the optical component according to Embodiment 4 of the present invention. FIG. 9 schematically shows a cross section. The optical component is provided on the optical waveguide forming layer 102 formed on the main surface of the substrate 101, the heat generating portion 103 disposed on a part of the optical waveguide forming layer 102, and one end of the optical waveguide forming layer 102. And a spatial light beam input / output unit 104. The optical component according to the fourth embodiment includes a groove 105 formed on the back surface of the substrate 101 between the spatial light beam input / output unit 104 and the heat generating unit 103.

  The configuration described above is the same as in the first to third embodiments. In the fourth embodiment, a laser light source 501 made of a semiconductor laser is provided at the other end of the optical waveguide forming layer 102. For example, a part of the substrate 101 is thinned to form the terrace portion 101a on the main surface of the substrate 101 on the other end side of the optical waveguide forming layer 102, and the laser light source 501 is mounted on the terrace portion 101a. By providing the laser light source 501 in the terrace portion 101a, the optical axes of the laser light source 501 and the optical waveguide forming layer 102 are matched.

  A heater 502 is provided on the back side of the substrate 101 provided with the laser light source 501. The oscillation wavelength in the laser light source 501 is stabilized by the heater 502.

  In the fourth embodiment, the laser light source 501 and the heater 502 serve as the heat generating unit 103. The laser light output from the laser light source 501 enters the optical waveguide forming layer 102 and propagates, and is emitted from the spatial light beam input / output unit 104 as a light beam into the space. In the optical waveguide forming layer 102 between the laser light source 501 and the spatial light beam input / output unit 104, functional elements such as a wavelength multiplexer / demultiplexer, a polarization multiplexer / demultiplexer, and an optical waveguide isolator are integrated. May be. An electrical wiring (not shown) for driving the laser light source 501 is formed on the substrate 101 and the optical waveguide forming layer 102.

  When the laser light source 501 is driven, a certain amount of heat is generated. However, since the groove 105 is provided, the conduction of this heat to the spatial light beam input / output unit 104 is suppressed. In addition, since the groove 105 is provided, heat from the heater 502 for stabilizing the laser wavelength is suppressed from being transmitted to the spatial light beam input / output unit 104. Therefore, according to the fourth embodiment, the influence of heat conduction such as the heater temperature and the temperature of the laser light source 501 can be removed. Further, according to the fourth embodiment, the temperature control by the heater 502 can be performed more efficiently.

[Embodiment 5]
Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a configuration diagram showing the configuration of the optical component according to Embodiment 5 of the present invention. FIG. 10 schematically shows a cross section. The optical component is provided on the optical waveguide forming layer 102 formed on the main surface of the substrate 101, the heat generating portion 103 disposed on a part of the optical waveguide forming layer 102, and one end of the optical waveguide forming layer 102. And a spatial light beam input / output unit 104. The optical component according to the fourth embodiment includes a groove 105 formed on the back surface of the substrate 101 between the spatial light beam input / output unit 104 and the heat generating unit 103.

  The configuration described above is the same as in the first to fourth embodiments. In the fifth embodiment, an optical waveguide type semiconductor laser 601 is provided on the other end side of the optical waveguide forming layer 102. The semiconductor laser 601 becomes the heat generating part 103. The semiconductor laser 601 is, for example, a well-known distributed feedback (DFB) laser. The semiconductor laser 601 is, for example, a well-known distributed Bragg reflector (DBR) laser.

  In the fifth embodiment, the optical waveguide forming layer 102 is made of, for example, a semiconductor such as InP. A semiconductor laser 601 can be obtained by forming an active region in a part of the optical waveguide forming layer 102 and incorporating a resonator structure in the active region. A drive electrode 602 is provided in the active region, and a wiring 603 is connected to the drive electrode 602. For example, if a diffraction grating is combined as a resonator structure on the active region, a DFB laser can be obtained. Further, a DBR laser can be obtained by arranging a diffraction grating on the extension line of the active region. These can be manufactured by a known semiconductor process.

  In the fifth embodiment, the heater 502a is provided on the back surface of the substrate 101 in the region where the heat generating portion 103 is formed via the heat radiating component 401a. The heat dissipation component 401a is made of a metal such as aluminum or copper, for example. The heater 502 a is used for thermal stabilization of the semiconductor laser 601. The light output from the semiconductor laser 601 is output and guided to the optical waveguide forming layer 102 integrated in the same optical component, and is emitted from the spatial light beam input / output unit 104 to the outside of the circuit as a light beam. A certain amount of heat is generated from the semiconductor laser 601 thus driven. Since this groove 105 is provided as in the fourth embodiment, conduction of this heat to the spatial light beam input / output unit 104 is suppressed.

  In addition, since the groove 105 is provided for heat from the heater 502a for stabilizing the laser wavelength, conduction to the spatial light beam input / output unit 104 is suppressed. Therefore, also in Embodiment 5, the influence of conduction such as the heater temperature and the temperature by the semiconductor laser 601 can be removed. Also in the fifth embodiment, the temperature control by the heater 502a can be performed more efficiently.

[Embodiment 6]
Next, Embodiment 6 of the present invention will be described with reference to FIG. FIG. 11 is a block diagram showing the configuration of the optical component according to Embodiment 6 of the present invention. FIG. 11 schematically shows a cross section. This optical component is provided on the optical waveguide forming layer 102 formed on the main surface of the substrate 101a, the heat generating portion 103 disposed on a part of the optical waveguide forming layer 102, and one end of the optical waveguide forming layer 102. And a spatial light beam input / output unit 104. The optical component in the fourth embodiment includes a groove 105 formed on the back surface of the substrate 101 a between the spatial light beam input / output unit 104 and the heat generating unit 103. In the sixth embodiment, the substrate 101a is made thinner than the substrate 101 in the third embodiment.

  The other end of the optical waveguide forming layer 102 is provided with an optical input / output unit 106. An optical fiber 107 is optically connected to the optical input / output unit 106. The optical fiber 107 is fixed to the substrate 101a and the auxiliary component 109 attached to the substrate 101a by a fixing component 108. The fixed component 108 is bonded to the side surface of the substrate 101a and the auxiliary component 109 with an adhesive layer 110 made of an adhesive.

  The sixth embodiment also includes a heat sink 401 connected to the back surface of the substrate 101a in the region where the heat generating portion 103 is formed. The sixth embodiment also includes a holding structure 402 that is connected to the back surface of the substrate 101 on the side where the spatial light beam input / output unit 104 is disposed from the groove 105. The holding structure 402 is thermally separated from the heat sink 401.

  The above-described configuration other than the substrate 101a is the same as that of the third embodiment. In the sixth embodiment, by using the thinner substrate 101a, heat generated in the heat generating portion 103 is quickly transmitted to the substrate side, and heat conduction to the heat sink 401 via the substrate 101a is performed in the third embodiment. Can be performed more efficiently. In the sixth embodiment, the heat conductive surface of the heat sink 401 is bonded and fixed to the back surface of the substrate 101a by an elastic adhesive layer 403a made of an adhesive that has thermal conductivity and elastically deforms. In this structure, the stress generated between the substrate 101a and the heat sink 401 is absorbed by the elastic adhesive layer 403a.

[Embodiment 7]
Next, Embodiment 7 of the present invention will be described with reference to FIG. FIG. 12 is a block diagram showing the configuration of the optical component according to Embodiment 7 of the present invention. FIG. 12 schematically shows a cross section. The optical component is provided on the optical waveguide forming layer 102 formed on the main surface of the substrate 101, the heat generating portion 103 disposed on a part of the optical waveguide forming layer 102, and one end of the optical waveguide forming layer 102. And a spatial light beam input / output unit 104. The optical component according to the fourth embodiment includes a groove 105 formed on the back surface of the substrate 101 between the spatial light beam input / output unit 104 and the heat generating unit 103.

  The configuration described above is the same as that of the above-described embodiment. In the seventh embodiment, first, a spatial light beam input / output unit 106 a provided at the other end of the optical waveguide forming layer 102 is provided. The spatial light beam input / output unit 106 a emits a light beam from the end of one of the optical waveguides on the other end side of the optical waveguide forming layer 102 to the space. Further, the spatial light beam input / output unit 104 causes the light beam from the space to enter the end of one of the optical waveguides on the other end side of the optical waveguide forming layer 102.

  In the seventh embodiment, a groove portion 701 formed on the back surface of the substrate 101 is provided at a portion between the spatial light beam input / output unit 106 a and the heat generating unit 103.

  Note that in Embodiment 7, the heat sink 401 is provided on the back surface of the substrate 101 between the groove 105 and the groove 701. In the seventh embodiment, the holding structure 402 has a back surface of the substrate 101 on the side where the spatial light beam input / output unit 104 is disposed from the groove 105 and a space between the spatial light beam input / output unit 106 a and the groove 701. The back surface of the substrate 101 is connected.

  In the above-described seventh embodiment, the spatial light beam input / output unit 104 and the spatial light beam input / output unit 106a are provided at both ends of the optical waveguide forming layer 102, and a light beam is transmitted into the space on the other end side in addition to one end side. It is configured to input and output. Further, the spatial light beam input / output unit 104 and the spatial light beam input / output unit 106a at both ends are thermally separated by the groove 105 and the groove 701. Accordingly, the above-described problem is also suppressed in the spatial light beam input / output unit 106a on the other end side.

  As described above, according to the present invention, since the groove is provided on the back surface of the substrate between the spatial light beam input / output unit and the heat generating unit, it is affected by the heat from the heat generating unit such as a thermal phase shifter. Deterioration of optical characteristics and reliability of the light beam input / output to / from the spatial optical system can be suppressed.

  The present invention is not limited to the embodiment described above, and many modifications and combinations can be implemented by those having ordinary knowledge in the art within the technical idea of the present invention. It is obvious.

  For example, not only quartz glass but also an optical waveguide using a polymer made of an organic material may be used. Alternatively, an optical waveguide made of a semiconductor such as Si or indium phosphide (InP) or a compound semiconductor may be used. Further, an optical waveguide composed of lithium niobate (LN) or the like may be used. The optical waveguide is not limited to the buried optical waveguide, and the same applies to a rib optical waveguide, a ridge optical waveguide, a mesa optical waveguide, a high mesa optical waveguide, a photonic crystal waveguide, and the like.

  The substrate 101 may be made of a material having a higher thermal conductivity than the material constituting the optical waveguide. For example, single crystal Si, polycrystalline Si, amorphous Si, tungsten, tungsten silicide, quartz, lithium tantalate, aluminum nitride, indium phosphide, crystal, or the like is suitable as the material of the substrate 101.

  In addition, a core and a clad are formed on the optical waveguide forming layer of the planar optical waveguide, and further, a phase shifter is formed as a heating element, but a heating element such as a laser light source is integrally formed in a process or Alternatively, a structure in which the optical waveguide forming layer is integrated and integrated may be employed. Further, the type of the optical waveguide is not limited as long as it imparts a function to the optical waveguide by an external electrical response or the like and generates heat. For example, a phase shifter using an electro-optic effect, a phase shifter using a carrier effect, a semiconductor optical amplifier, or the like may be used. Of course, this embodiment does not depend on the circuit configuration or the function of the circuit. Further, an appropriate optical circuit may be formed in the optical waveguide according to the application.

  DESCRIPTION OF SYMBOLS 101 ... Board | substrate, 102 ... Optical-waveguide formation layer, 103 ... Heat generating part, 104 ... Spatial light beam input / output part, 105 ... Groove part, 106 ... Light input / output part, 107 ... Optical fiber, 108 ... Fixed component 109, 109 ... Auxiliary Parts, 110 ... adhesive layer, 121 ... space.

Claims (7)

An optical waveguide forming layer comprising an optical waveguide formed on the main surface of the substrate;
A heat generating part that emits heat disposed in a part of the optical waveguide forming layer;
A spatial light beam input / output unit that is provided at one end of the optical waveguide forming layer, emits a light beam into the space from the optical waveguide forming layer, and makes the light beam from the space enter the optical waveguide forming layer;
An optical component comprising: a groove formed on a back surface of the substrate between the spatial light beam input / output unit and the heat generating unit. The optical component according to claim 1,
An optical component comprising a reinforcing member made of a material having a lower thermal conductivity than the substrate and filled in the groove. The optical component according to claim 1 or 2,
An optical component comprising: a heat dissipation component connected to the back surface of the substrate in a region where the heat generating portion is formed. In the optical component according to any one of claims 1 to 3,
An optical component comprising: a holding structure that holds the substrate connected to the back surface of the substrate on the side where the spatial light beam input / output unit is disposed from the groove. In the optical component according to any one of claims 1 to 4,
The optical component, wherein the heat generating part is a thin film heater that heats a part of the optical waveguide of the optical waveguide forming layer. In the optical component according to any one of claims 1 to 4,
The optical part, wherein the heat generating part is a semiconductor laser. The optical component according to any one of claims 1 to 6,
The optical component, wherein the substrate is made of any one of single crystal Si, polycrystalline Si, amorphous Si, tungsten, tungsten silicide, quartz, lithium tantalate, aluminum nitride, indium phosphide, and quartz.

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