JP6636903B2 - Optical components - Google Patents

Description

  The present invention relates to an optical component including a planar optical waveguide circuit that includes a heating unit and inputs and outputs light to and from a spatial optical system.

  In order to cope with an increase in the capacity of information communication traffic, wavelength division multiplex transmission is realized in a communication network using optical fibers. Further, many optical communication devices that support wavelength multiplex transmission have been put into practical use, but further higher functionality is desired in order to cope with a further increase in capacity in the future.

  As such an optical communication device, there is a planar optical waveguide. 2. Description of the Related Art A planar optical waveguide is widely used because a light multiplexing / demultiplexing function, a branching function, a switching function, and the like can be mounted with high accuracy. In particular, a silica-based planar lightwave circuit (PLC) made of silica glass has excellent coupling with optical fibers and high material reliability, and is therefore used as a splitter, wavelength multiplexer / demultiplexer, optical switch, etc. It is applied to a wide variety of functional devices for optical communication. Further, optical waveguides made of semiconductor materials and optical functional devices using Si optical waveguides having a silicon core as cores have been widely applied because of their excellent integration with light receiving and emitting devices and miniaturization.

  Particularly, in optical switches, a ROADM (Reconfigurable Optical Add / Drop Multiplexer) system has been introduced. In a conventional optical switch, a method in which a transmitted optical signal is converted into an electric signal and then the path is switched by the electric switch has been mainly used. On the other hand, in the ROADM system, the characteristics of an optical signal such as high speed and wide band are utilized, and an optical switch or the like is used to perform an add / drop operation using the optical signal as it is.

  In a ROADM system, a wavelength-division multiplexing network using optical fibers is made into a ring type, and at each node of the ring network, a process of adding and dropping an optical signal and passing an optical signal that does not need to be added or dropped as an optical signal is performed. Is being done. Known devices required for the ROADM system include 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.

  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, and changes the phase by changing the refractive index of the optical waveguide by applying heat to the heater, thereby turning ON / OFF the output light and controlling the light. Intensity adjustment and phase modulation are performed. This technique using a heater is also called a thermal phase shifter.

  In addition, phase shifters based on an electro-optic effect, a plasma effect due to carrier injection, and the like are known. Each of the phase shifters is arranged near the optical waveguide, and electric wiring for electrically controlling the phase shifter is formed on the optical waveguide. Further, in a semiconductor PLC, an optical waveguide type optical switch using an optical amplification effect of a semiconductor or electric field absorption for electrically controlling light absorption of an optical waveguide is also known.

  Further, in addition to the above-described optical waveguide type optical switch, a wavelength selective switch (WSS) module capable of switching a wavelength multiplexed signal in units of wavelength channels is also known as a more sophisticated optical switch. . The WSS module includes an input / output system including an optical fiber, a spatial optical system including a diffraction grating and a lens, and a MEMS or a phase modulation element that is a spatial light switching 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 an input / output system of an optical fiber by using the above-described planar optical waveguide formed of a silica PLC has been proposed (Non-Patent Document 1). reference). In this module, an optical fiber is connected to one of the optical waveguides, and light input and output from the optical fiber passes through the optical waveguide to control a beam diameter, a phase, and the like. The light beam whose beam diameter and phase are controlled is input / output to / from a spatial optical system from one of the optical waveguides 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 or a phase modulation element used for WSS or the like is used. It has been reported that the combination and application to a high-performance add / drop switch for ROADM are available.

  In addition to the optical switch, as described in Patent Document 1, there has been reported an application of integrating a planar optical waveguide and a light receiving / emitting element such as a laser or a photodiode via a spatial optical system. The fusion of planar optical waveguides and spatial optics is advancing.

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 for 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 be stable. For this reason, in general, reliability is secured 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 emission position, emission angle, and beam shape of a light beam. In the technique using the thermal phase shifter, generated heat is applied to the beam input / output unit. For this reason, the following problems occur. First, the optical waveguide chip itself thermally expands, and as a result, the emission position of the light beam shifts. Second, a stress due to a thermal change is applied to a fixing portion using an adhesive or the like, and the reliability of the fixing portion is deteriorated. Third, the refractive index of the optical waveguide formed in the input / output unit changes due to heat or the like, the state of interference of light in the input / output unit changes, and the quality of the light beam changes.

  Due to the above-mentioned problem, there is a problem that the optical characteristics and reliability of the entire system are deteriorated without matching with the spatial optical system.

  The present invention has been made to solve the above problems, and has been made in consideration of the optical characteristics of a light beam input / output to / from a spatial optical system due to the influence of heat from a heating unit such as a thermal phase shifter. And 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 emits heat disposed in a part of the optical waveguide forming layer, and an optical waveguide forming layer. A spatial light beam input / output unit, provided at one end, for emitting a light beam from the optical waveguide forming layer to the space and for allowing the light beam from the space to enter the optical waveguide forming layer; a spatial light beam input / output unit and a heating unit And a groove formed on the back surface of the substrate.

In the optical component, Ru provided with a reinforcing member that is filled in the groove is constructed from a low material thermal conductivity than the substrate.

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

  In the above optical component, a holding structure for holding the substrate by connecting to the back surface of the substrate on the side where the spatial light beam input / output unit is arranged from the groove may be provided.

  In the above optical component, the heat generating portion is a thin film heater for heating a part of the optical waveguide of the optical waveguide forming layer. The heating section is a semiconductor laser.

  In the optical component described above, the substrate may be made of any one 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 the thermal phase shifter is provided. An excellent effect is obtained that deterioration of the optical characteristics and reliability of the light beam input / output to / from the optical system can be suppressed.

FIG. 1 is a configuration diagram showing a configuration of an 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 illustrating a partial configuration of the optical component according to Embodiment 1 of the present invention. FIG. 4A is a configuration diagram illustrating 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 showing 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 the first embodiment of the present invention. FIG. 7 is a configuration diagram illustrating a configuration of an optical component according to Embodiment 2 of the present invention. FIG. 8 is a configuration diagram illustrating a configuration of an optical component according to Embodiment 3 of the present invention. FIG. 9 is a configuration diagram showing a configuration of an optical component according to Embodiment 4 of the present invention. FIG. 10 is a configuration diagram showing a configuration of an optical component according to Embodiment 5 of the present invention. FIG. 11 is a configuration diagram showing a configuration of an optical component according to Embodiment 6 of the present invention. FIG. 12 is a configuration diagram showing a configuration of an 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 a configuration of an 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 a main surface of a 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 formed on a substrate 101 made of single crystal silicon (Si) by an optical waveguide forming layer 102 made of glass (silicon oxide).

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

For example, the spatial light beam input / output unit 104 is applied to a WSS or the like via a spatial optical system including a lens, a phase modulation element (not shown), and optically connected to a light receiving unit (not shown) such as a photodiode. Thus, 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, if necessary, to increase the beam diameter. 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 111a and the second core 111b are embedded in the cladding layer 113. Each core forms an optical waveguide.

  In the heating section 103, a thin film heater 114a is formed on the cladding layer 113 above the first core 111a. The 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 above the second core 111b. The wiring 115b is connected to the thin film heater 114b so that a current can be applied. The application of current causes the thin-film heaters 114a and 114b to generate heat. These constitute a thermal phase shifter. In the first embodiment, as described above, the thin film heater that heats a part of any one of the optical waveguides of the optical waveguide forming layer 102 becomes the heat generating unit 103.

  Each wiring is routed on the optical component, is 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 above-described example, an optical circuit such as a Mach-Zehnder optical switch or an optical variable attenuator is formed by two thin film heaters. By applying heat to the core by the 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. Utilizing this, it is used as an optical switch or an optical variable attenuator. Further, by connecting this configuration continuously, an arbitrary 1 × M switch (M is an integer) can be formed. In this example, the thin film heater is formed on two optical waveguides of Mach-Zehnder, but may be formed on only one of them.

  In addition to the above configuration, the optical component according to 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 heating unit 103. The groove 105 is formed on the back surface of the substrate 101 so as to divide the area where the spatial light beam input / output section 104 is arranged and the area where the heat generating section 103 is arranged. As shown in FIG. 1, the groove 105 may be in a state where a part of the substrate is slightly left on the optical waveguide forming layer 102 side. Further, the groove 105 may be formed so as to penetrate the substrate 101. However, by forming the groove 105 through the substrate 101, 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 optical input / output unit 106. The optical fiber 107 is fixed to the substrate 101 and an 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 optical 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 according to the first embodiment 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 not driving the thin film heater 114b. Heat from the thin film heater 114a is transmitted to the cladding layer 113 around the first core 111a in an approximately isotropic manner. The heat conducted in this manner is conducted to the cladding layer 113 below the first core 111a, and further to the substrate 101.

  Here, the thermal conductivity of the substrate 101 made of single crystal Si is about two orders of magnitude higher than the thermal conductivity of glass. For this reason, in the substrate 101, heat conduction progresses relatively quickly, and heat is immediately transmitted to the entire substrate 101. As a result, during the time required for the heat to reach the substrate 101 from the thin film heater 114a, the heat is transmitted approximately isotropically to each core and the cladding layer 113. However, once the heat reaches the substrate 101, the heat flow is dominant in the substrate 101, which means that heat conduction in each core portion and the cladding layer 113 is not performed except in some regions.

  Further, the wiring made of a metal such as Au has a very high thermal conductivity, so that the heat of the heater is immediately conducted. Therefore, the same phenomenon as described above occurs immediately below the wiring.

  In the optical switch, a plurality of heaters are arranged and a large number of wirings are formed, so that heat from near the heaters and near the wirings is also transmitted to the substrate. As a result, in the configuration having no groove shown in FIG. 4A, heat is also transmitted to the spatial light beam input / output unit 104 via the substrate 101. For this reason, for example, the optical component thermally expands due to the heat generated each time the optical switch operation is performed, and the emission position of the light beam changes. Further, stress due to thermal expansion is applied to a portion where the optical fiber 107 and the like are fixed, and the reliability of the fixed 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 state of interference of light 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 thereof are deteriorated as a whole system without matching with the spatial optical system.

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

In order to solve the above problem, according to the first embodiment of the present invention, since the groove portion 105 having the 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 the light to the spatial light beam input / output unit 104 side of the substrate 101. Therefore, most of the heat generated in the heating unit 103 is transmitted to the heat generating portion side of the base plate 101, it will be 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 separated by a certain distance or more, most of the heat is transmitted to the substrate 101 in the region where the heat generating portion 103 is arranged, and the substrate 101 Is transmitted and radiated from the exposed surface (such as the back surface) of the device. As a result, in the first embodiment, the time required for the heat from the heat generating unit 103 to be 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 connecting a heat radiating component that causes heat transfer more efficiently to the back surface of the substrate 101 in a region where the heat generating portion 103 is formed through thermal conductive grease or the like, almost all heat is radiated. It is transmitted to parts. As a result, 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 heat insulating structure of the related art will be described. Conventionally, a structure shown in FIGS. 4B and 4C is known as a technique for insulating a heater arranged on an optical waveguide. 4B and 4C show cross sections perpendicular to the waveguide direction. Each of these structures is used for the purpose of suppressing heat radiation and efficiently applying heat from the heater to the core immediately below the heater, and is fundamentally different from this structure. 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 hardly transmitted to the substrate, and the heat is efficiently applied to the core immediately below the heater. As a result, the refractive index of the optical waveguide can be changed by the core immediately below the heater with lower power consumption.

  In the configuration shown in FIG. 14C, the optical waveguide of the core where the heater is arranged is separated from the optical waveguide of another core. Therefore, heat from the heater is not transmitted to the substrate via another optical waveguide, and heat is efficiently applied to the core immediately below the heater. As a result, also in this configuration, the refractive index of the optical waveguide can be changed by the core immediately below the heater with lower power consumption.

  In these technologies, heat is transmitted to the substrate side as a result, and thus the heat is transmitted to the entire optical component. Further, since the separated structure is along the waveguide direction, heat is conducted to the entire chip via a wiring portion or 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 purpose is fundamentally different.

  Next, a method for manufacturing an optical component according to the first embodiment will be briefly described. For example, using a well-known SOI (Silicon on Insulator) substrate, 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, a well-known deposition method such as a plasma CVD method is used to deposit Si oxide to form a cladding layer, thereby forming an optical waveguide. Next, a thin film heater is formed at a predetermined location, and a wiring or the like connected to the thin film heater is formed.

  In addition, regarding the method of forming the optical waveguide, in addition to the above, a glass layer to be an under clad is formed on a Si substrate using a flame deposition method or the like, and the refractive index is higher than that of the clad by a photolithography technique and an etching technique. A method of embedding a glass material to be a high core and then depositing a glass layer again to form a core-embedded optical waveguide 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 105 is formed on the back surface of the substrate 101. For example, a groove pattern can be formed by forming a mask pattern having an opening in the groove portion 105 and selectively etching away the back surface of the substrate 101 using the mask pattern. As the 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 sectional shape in the extending direction is triangular, and the width becomes narrower toward the optical waveguide forming layer 102. Groove portion 105a. For example, when the main surface is selectively etched with an alkaline aqueous solution from the back surface of the substrate 101 made of single crystal Si having a plane orientation of (100) using the above mask pattern, the substrate 101 has a tilt angle of about 55 degrees ( Etching is performed to expose the (111) plane. Thereby, a groove 105a having a triangular cross section can be formed. The groove 105a may be formed by dicing using an oblique blade.

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

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

  As shown in FIG. 6C, in addition to the groove 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 A groove 205b may be formed on the back surface of the substrate 101 between the other end of the heat generating unit 103 and the heat generating unit 103 so as to separate the formation region of the heat generating unit 103.

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

[Embodiment 2]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a configuration diagram illustrating a configuration of an 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 a main surface of a substrate 101. Further, the optical component includes a heat generating portion 103 provided in a part of the optical waveguide forming layer 102. Further, this optical component includes a spatial light beam input / output unit 104 provided at one end of the optical waveguide forming layer 102.

  Further, the optical component according to 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. An 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 an 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 in the first embodiment. In the second embodiment, there is provided a reinforcing member 301 made of a substance having a lower thermal conductivity than the substrate 101 and 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, epoxy resin, silicone resin, acrylic resin, or the like. As long as there is no mixture, these resins are suitable because they have sufficiently lower thermal conductivity than glass and Si and have a small Young's modulus.

  According to the second embodiment, similarly to the above-described first embodiment, it is possible to suppress the fluctuation of the light beam emission position to the space, the deterioration of the light beam quality, or the influence / deterioration of the heat application to the adhesive fixing portion. Become. Since the reinforcing member 301 has a small thermal conductivity, heat conduction via the reinforcing member 301 is very small. Further, by connecting a heat radiating component that causes heat transfer more efficiently to the substrate 101 via a heat conductive grease or the like, almost all heat is transmitted to the heat radiating component. As a result, 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 105 is filled with the reinforcing member 301, it is possible to prevent a decrease in mechanical strength and deformation of the groove 105 of the substrate 101. As a result, it is possible to prevent the mechanical strength of the optical waveguide forming layer 102 from being lowered or deformed in this portion, and to realize a more reliable optical component. Here, it is desirable that the reinforcing member 301 is made of a polymer resin, and is formed by filling after forming the groove 105. In particular, it is preferable to form the reinforcing member 301 by using a thermosetting resin or a photocurable resin, filling the groove 105 with these materials, and then curing the material 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. Therefore, the Young's modulus of the reinforcing member 301 is 1 × 10 5 at room temperature (25 ° C.). ^It is preferably about ⁹ Pa or less.

[Embodiment 3]
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a configuration diagram illustrating a configuration of an optical component according to Embodiment 3 of the present invention. FIG. 8 schematically shows a cross section. This optical component was provided on an optical waveguide forming layer 102 formed on the main surface of the substrate 101, a heat generating portion 103 arranged 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 heating unit 103. Further, this optical component 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 an 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 in the first embodiment. In addition to these, in the third embodiment, first, a heat sink (heat dissipating component) 401 connected to the back surface of the substrate 101 in the 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 is provided with fins and a plurality of rods on a heat radiation surface, and is connected to the back surface of the substrate 101 at a heat conduction surface opposite to the heat radiation surface. It is preferable to increase the surface area by providing fins or the like so that heat transfer or radiant heat is further 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 made of a heat transfer grease, a film type adhesive or the like. Further, the adhesive layer 403 may be made of solder. Further, a heat sink 401 may be bonded to the back surface of the substrate 101 by using a metal bump or the like as the adhesive layer 403. The heat sink 401 may be made of a metal such as aluminum or copper having a thermal conductivity equal to or higher than that of the substrate 101.

  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 is less likely to be transmitted to the substrate 101 on which the spatial light beam input / output unit 104 is formed. .

  Further, 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 from the groove 105 by an adhesive layer 404 made of solder, adhesive, or the like. It is preferable that the holding structure 402 is the same as or integrated with a housing or a package that holds the optical component. The holding structure 402 may be made of a general-purpose metal such as SUS, or an alloy appropriate for the purpose of the housing or package. Here, the material forming the holding structure 402 preferably has a thermal expansion coefficient close to that of the substrate 101. Therefore, when the substrate 101 is made of Si, the holding structure 402 is preferably made of Kovar or Invar. Further, 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 according to Embodiment 3 has a structure fixed to the holding structure 402, and it is possible to suppress displacement of a light beam emitted to space with respect to the holding structure 402. It is possible. For example, the holding structure 402 can be connected to a lens, a phase modulation element, or a fixed part of a photodiode arranged 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 portion 103.

[Embodiment 4]
Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a configuration diagram showing a configuration of an optical component according to Embodiment 4 of the present invention. FIG. 9 schematically shows a cross section. This optical component was provided on an optical waveguide forming layer 102 formed on the main surface of the substrate 101, a heat generating portion 103 arranged 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 heating unit 103.

  The configuration described above is similar to 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, on a main surface of the substrate 101 on the other end side of the optical waveguide forming layer 102, a part of the substrate 101 is thinned to form a terrace 101a, and the laser light source 501 is mounted on the terrace 101a. By providing the laser light source 501 on the terrace portion 101a, the optical axes of the laser light source 501 and the optical waveguide forming layer 102 are made to coincide.

  Further, a heater 502 is provided on the back surface side of the substrate 101 on which the laser light source 501 is provided. The oscillation wavelength of 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, propagates, and is emitted as a light beam from the spatial light beam input / output unit 104 to 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 type isolator are integrated. You may. Note that electric wiring (not shown) for driving the laser light source 501 is formed on the substrate 101 and on 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, conduction of this heat to the spatial light beam input / output unit 104 is suppressed. Further, the heat from the heater 502 for stabilizing the laser wavelength is also suppressed from being transmitted to the spatial light beam input / output unit 104 because the groove 105 is provided. 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 eliminated. Further, according to the fourth embodiment, the temperature control by 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 a configuration of an optical component according to Embodiment 5 of the present invention. FIG. 10 schematically shows a cross section. This optical component was provided on an optical waveguide forming layer 102 formed on the main surface of the substrate 101, a heat generating portion 103 arranged 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 heating 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 unit 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 into 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 on the active region as a resonator structure, a DFB laser can be obtained. Further, a DBR laser can be obtained by arranging a diffraction grating on an extension of the active region. These can be manufactured by a known semiconductor process.

  Further, 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 radiation component 401a. The heat dissipating component 401a is made of, for example, a metal such as aluminum or copper. The heater 502a is used for stabilizing the heat of the semiconductor laser 601. The light output from the semiconductor laser 601 is output to the optical waveguide forming layer 102 integrated in the same optical component, guided, and emitted as a light beam from the spatial light beam input / output unit 104 to the outside of the circuit. A constant heat is generated from the semiconductor laser 601 driven in this manner. This heat is suppressed from being conducted to the spatial light beam input / output unit 104 because the groove 105 is provided as in the fourth embodiment.

  Further, since the grooves 105 are provided, the heat from the heater 502 a for stabilizing the laser wavelength is also suppressed from being conducted to the spatial light beam input / output unit 104. Therefore, also in the fifth embodiment, the influence of conduction such as the heater temperature and the temperature by the semiconductor laser 601 can be eliminated. Further, also in the fifth embodiment, the temperature control by the heater 502a can be performed more efficiently.

Embodiment 6
Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a configuration diagram showing a configuration of an optical component according to Embodiment 6 of the present invention. FIG. 11 schematically shows a cross section. This optical component was provided on an optical waveguide forming layer 102 formed on the main surface of the substrate 101a, a 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 101a between the spatial light beam input / output unit 104 and the heating unit 103. In the sixth embodiment, the substrate 101a is a thin layer of the substrate 101 in the third embodiment.

  An 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 101a and the auxiliary component 109 attached to the substrate 101a by a fixing component. 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 a region where the heat generating unit 103 is formed. Also in the sixth embodiment, a holding structure 402 connected to the back surface of the substrate 101 on the side where the spatial light beam input / output unit 104 is arranged from the groove 105 is provided. 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 a thinner substrate 101a, the heat generated in the heat generating portion 103 is transmitted to the substrate more quickly, and the heat conduction to the heat sink 401 via the substrate 101a is reduced to 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 having thermal conductivity and elastically deforming. 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, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 12 is a configuration diagram showing a configuration of an optical component according to Embodiment 7 of the present invention. FIG. 12 schematically shows a cross section. This optical component was provided on an optical waveguide forming layer 102 formed on a main surface of a substrate 101, a 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 heating unit 103.

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

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

  In the seventh embodiment, 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 is formed between the groove 105 and the back surface of the substrate 101 on the side where the spatial light beam input / output unit 104 is disposed, and between the spatial light beam input / output unit 106a and the groove 701. To the back surface of the substrate 101.

  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 the light beam is applied to the space not only at one end but also at the other end. 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. Therefore, 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, the groove is provided by the influence of heat from the heat generating unit such as the thermal phase shifter. Deterioration of optical characteristics and reliability of a light beam input / output to / from the spatial optical system can be suppressed.

  Note that the present invention is not limited to the above-described embodiments, and many modifications and combinations can be made by those having ordinary knowledge in the art without departing from the technical concept of the present invention. That is clear.

  For example, an optical waveguide using a polymer made of an organic material is not limited to quartz glass. Further, 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 made of lithium niobate (LN) or the like may be used. Further, the optical waveguide is not limited to the embedded optical waveguide, and the same applies to a rib-type optical waveguide, a ridge-type optical waveguide, a mesa-type optical waveguide, a high-mesa-type 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 of the optical waveguide. For example, single-crystal Si, polycrystalline Si, amorphous Si, tungsten, tungsten silicide, quartz, lithium tantalate, aluminum nitride, indium phosphide, quartz, or the like is suitable as the material for the substrate 101.

  Further, a core and a clad are formed in the optical waveguide forming layer of the planar optical waveguide, and a phase shifter is formed as a heating element. Alternatively, a structure in which the optical waveguide forming layer is formed and then integrated and integrated may be used. In addition, the type does not depend on the type as long as it gives a function to the optical waveguide by an external electrical response or the like and generates heat. For example, a phase shifter using the electro-optic effect, a phase shifter using the carrier effect, or a semiconductor optical amplifier may be used. In addition, 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 its use.

  DESCRIPTION OF SYMBOLS 101 ... Substrate, 102 ... Optical waveguide formation layer, 103 ... Heating part, 104 ... Spatial light beam input / output part, 105 ... Groove part, 106 ... Optical input / output part, 107 ... Optical fiber, 108 ... Fixed parts 109, 109 ... Auxiliary Parts, 110: adhesive layer, 121: space.

Claims (6)

An optical waveguide forming layer including an optical waveguide formed on the main surface of the substrate,
A heat-generating portion 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 from the optical waveguide forming layer to a space, and allows the light beam from the space to enter the optical waveguide forming layer;
A groove formed on the back surface of the substrate between the spatial light beam input / output unit and the heating unit ;
An optical component, comprising: a reinforcing member made of a substance having a lower thermal conductivity than the substrate and filled in the groove . An optical component according to claim 1 Symbol placement,
An optical component, comprising: a heat radiating component connected to a back surface of the substrate in a region where the heat generating portion is formed. An optical component according to claim 1 or 2, wherein,
An optical component, comprising: a holding structure that is connected to a back surface of the substrate on a side where a spatial light beam input / output unit is arranged from the groove and holds the substrate. The optical component according to any one of claims 1 to 3 ,
The optical component, wherein the heat generating portion is a thin film heater that heats a part of the optical waveguide of the optical waveguide forming layer. The optical component according to any one of claims 1 to 3 ,
An optical component, wherein the heat generating part is a semiconductor laser. The optical component according to any one of claims 1 to 5 ,
An 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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