Light detection device

Abstract

A light detection device includes a Fabry-Perot interference filter having a light transmission region provided on a prescribed line, a light detector disposed on one side of the Fabry-Perot interference filter with respect to the line, a package having an opening on the other side of the Fabry-Perot interference filter with respect to the line, a light transmission member disposed on the package in a manner to close the opening, and a temperature adjustment element thermally connected to the Fabry-Perot interference filter and the light detector and having a heat absorption region. The heat absorption region is disposed on one side of the light detector with respect to the line.

Description

[0001] This application was filed on [date]. March 3, 2017 Application number is 201780015575.2 The invention is named Light detection Device A divisional application of the patent application. Technical Field

[0002] The present invention relates to a light detection device having a first mirror and a second mirror having a variable distance between them. Background Technology

[0003] Patent Document 1 describes a standard etalon section for an interferometer comprising a Fabry-Perot interferometer, a holder for holding the Fabry-Perot interferometer, a Peltier element mounted on the holder, and a vacuum container housing the Fabry-Perot interferometer, the holder, and the Peltier element. In this standard etalon section, a Peltier element is mounted on the side of the holder, relative to the light path from the light entrance window of the vacuum container through the Fabry-Perot interferometer to the light exit window of the vacuum container.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 1-250834 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] However, in the above structure, since the Fabry-Perot interferometer is cooled from the side by the Peltier element, there is a concern that the Fabry-Perot interferometer filter and photodetector may not be maintained at a uniform temperature when housed in the package. Furthermore, in the above structure, since the area near the light entrance window of the vacuum container is cooled by the Peltier element, there is a concern that condensation may occur in the light-transmitting member when the opening of the package housing the Fabry-Perot interferometer filter and photodetector is provided with a light-transmitting member.

[0009] The purpose of this invention is to provide a light detection device that can suppress condensation or cracking in the light-transmitting member used to allow light to enter the package, and can maintain the Fabry-Perot interferometer filter and photodetector housed in the package at a uniform temperature.

[0010] Technical means to solve the problem

[0011] One aspect of the present invention relates to a light detection device comprising: a Fabry-Perot interferometer filter having a first mirror and a second mirror at a variable distance from each other, and having a light-transmitting region disposed along a predetermined line, allowing light to pass through the distance corresponding to the distance between the first mirror and the second mirror; a photodetector disposed on one side of the Fabry-Perot interferometer filter, and detecting light that has passed through the light-transmitting region; a package having an opening on the other side of the Fabry-Perot interferometer filter, and housing the Fabry-Perot interferometer filter and the photodetector; a light-transmitting member disposed in the package to close the opening; and a temperature regulating element thermally connected to the Fabry-Perot interferometer filter and the photodetector, and having a first region that functions as both a heat-absorbing region and a heat-generating region; the first region being at least on one side of the photodetector.

[0012] In this photodetector, a first region of a temperature regulating element, functioning as both a heat-absorbing and heat-generating region, is located at least linearly to one side of the photodetector. Therefore, compared to a case where the first region of the temperature regulating element is located linearly to the side of the Fabry-Perot interferometer filter and the photodetector, the Fabry-Perot interferometer filter and the photodetector are maintained at a uniform temperature. Furthermore, at least linearly, the Fabry-Perot interferometer filter and the photodetector are disposed between the light-transmitting member and the first region of the temperature regulating element. This suppresses condensation in the light-transmitting member caused by excessive cooling, resulting in a large temperature difference between the light-transmitting member and the outside air temperature (the operating environment temperature of the photodetector). Additionally, it suppresses the formation of cracks in the light-transmitting member caused by excessive heating, resulting in a large temperature difference between the light-transmitting member and the outside air temperature. Therefore, according to this optical detection device, condensation or cracks can be suppressed in the light-transmitting component used to incident light into the package, and the Fabry-Perot interferometer filter and photodetector housed in the package can be maintained at a uniform temperature.

[0013] In one aspect of the light detection device according to the present invention, when viewed from a direction parallel to the line, the outer edge of the opening may be located inside the outer edge of the Fabry-Perot interferometer filter, the temperature regulating element is thermally connected to the package, and a second region functions as both a heat-absorbing and heat-generating region. In this structure, for example, compared to the case where the outer edge of the opening is located outside the outer edge of the Fabry-Perot interferometer filter, heat is more easily transferred between the second region of the temperature regulating element (which functions as both a heat-absorbing and heat-generating region) and the light-transmitting member via the package. Therefore, according to this structure, condensation or cracking in the light-transmitting member can be more reliably suppressed.

[0014] In one aspect of the optical detection device according to the present invention, the outer edge of the light-transmitting member may be located outside the outer edge of the Fabry-Perot interferometer filter when viewed from a direction parallel to the line. In this structure, for example, compared to the case where the outer edge of the light-transmitting member is located inside the outer edge of the Fabry-Perot interferometer filter, the contact area between the light-transmitting member and the package is increased, and heat is easily transferred between the light-transmitting member and the package. Therefore, according to this structure, condensation or cracking in the light-transmitting member can be more reliably suppressed.

[0015] In one embodiment of the optical detection device according to the present invention, a temperature regulating element may be disposed within a package, a photodetector may be disposed on the temperature regulating element, and a Fabry-Perot interferometer filter may be disposed on the temperature regulating element such that the photodetector is located between the temperature regulating element and the Fabry-Perot interferometer filter. According to this structure, the Fabry-Perot interferometer filter and the photodetector can be efficiently maintained at a uniform temperature in a small and simple structure.

[0016] One aspect of the optical detection device according to the present invention may further include: a support member that supports the outer portion of the light-transmitting region in the bottom surface of the Fabry-Perot interferometer filter; and a heat-conducting member that contacts the side surface of the Fabry-Perot interferometer filter and the support member. In this structure, for example, compared to the case where no heat-conducting member is provided that contacts the side surface of the Fabry-Perot interferometer filter and the support member, heat is easily transferred via the support member between the Fabry-Perot interferometer filter and the first region of the temperature regulating element. Therefore, according to this structure, the Fabry-Perot interferometer filter and the photodetector can be maintained at a uniform temperature efficiently.

[0017] In one embodiment of the optical detection device according to the present invention, the heat-conducting member may also be an adhesive member that bonds the Fabry-Perot interferometer filter to the support member. According to this structure, the Fabry-Perot interferometer filter on the support member can be kept in a stable state.

[0018] In one embodiment of the optical detection device of the present invention, the support member may have a mounting surface on the outer side of the light-transmitting region of the bottom surface on which the Fabry-Perot interferometer filter is placed, with at least a portion of the side surface of the Fabry-Perot interferometer filter positioned on the mounting surface such that a portion of the mounting surface is disposed on the outer side of the side surface; a heat-conducting member is disposed at a corner formed by the side surface and a portion of the mounting surface, and contacts each of the side surface and the portion of the mounting surface. According to this structure, the Fabry-Perot interferometer filter and the photodetector can be maintained at a uniform temperature more efficiently, and the Fabry-Perot interferometer filter on the support member can be kept in a stable state more reliably.

[0019] In one embodiment of the optical detection device according to the present invention, the temperature regulating element may be embedded in the wall of the package. According to this structure, the volume of space within the package can be reduced, resulting in more efficient maintenance of a uniform temperature for the Fabry-Perot interferometer filter and the photodetector.

[0020] The effects of the invention

[0021] According to the present invention, a light detection device is provided that can suppress condensation or cracking in a light-transmitting member used to incident light into a package, and can maintain a Fabry-Perot interferometer filter and a photodetector housed in the package at a uniform temperature. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the light detection device according to the first embodiment.

[0023] Figure 2 yes Figure 1 A plan view of the optical detection device.

[0024] Figure 3 yes Figure 1 A plan view of the optical detection device, which includes a Fabry-Perot interferometer filter, a support structure, and a heat conduction structure.

[0025] Figure 4 yes Figure 1 A three-dimensional diagram of the Fabry-Perot interferometer filter for an optical detection device.

[0026] Figure 5 It is along Figure 4 A cross-sectional view of a Fabry-Perot interferometer filter with VV lines.

[0027] Figure 6 This is a cross-sectional view of the optical detection device according to the second embodiment.

[0028] Figure 7 This is a cross-sectional view of a modified example of the optical detection device according to the second embodiment.

[0029] Figure 8 This is a cross-sectional view of a modified example of the optical detection device according to the second embodiment. Detailed Implementation

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, identical or equivalent parts are given the same reference numerals in the drawings, and repeated parts are omitted.

[0031] [First Implementation]

[0032] [Structure of the optical detection device]

[0033] like Figure 1 As shown, the optical detection device 1A includes a package 2. The package 2 is a CAN package having a socket 3 and a cover 4. The cover 4 is integrally formed by a side wall 5 and a top wall 6. The top wall 6 is opposite to the socket 3 in a direction parallel to a straight line, i.e., a predetermined line L. The socket 3 and the cover 4 are made of, for example, metal and are hermetically joined together.

[0034] A temperature regulating element 50 is fixed to the inner surface 3a of the tube seat 3. The temperature regulating element 50 is, for example, a Peltier element, having a heat-absorbing region 50a and a heat-generating region 50b that are opposite to each other in a direction parallel to line L. The temperature regulating element 50 is arranged in the package 2 such that the heat-generating region 50b is located on the inner surface 3a side of the tube seat 3 and the heat-absorbing region 50a is located on the opposite side. Thus, the heat-generating region 50b of the temperature regulating element 50 is thermally connected to the package 2.

[0035] A wiring board 7 is fixed on the heat-absorbing region 50a of the temperature regulating element 50. The substrate material of the wiring board 7 can be, for example, silicon, ceramic, quartz, glass, plastic, etc. A photodetector 8 and a temperature compensation element such as a thermistor (not shown) are mounted on the wiring board 7. Thus, the heat-absorbing region 50a of the temperature regulating element 50 is thermally connected to the photodetector 8 and the temperature compensation element (not shown) via the wiring board 7.

[0036] A photodetector 8 is disposed on line L. More specifically, the photodetector 8 is disposed such that the center line of its light-receiving portion is aligned with line L. The photodetector 8 is, for example, an infrared detector using a quantum sensor such as InGaAs, or a thermal sensor such as a thermopile or a calorimeter. When detecting light in various wavelength bands of ultraviolet, visible, and near-infrared light, a silicon photodiode, for example, can be used as the photodetector 8. Furthermore, a single light-receiving portion can be provided in the photodetector 8, or multiple light-receiving portions can be arranged in an array. Moreover, multiple photodetectors 8 can be mounted on the wiring board 7.

[0037] On the wiring board 7, a plurality of support members 9 are fixed via heat-conducting members (not shown). The materials used for each support member 9 can be, for example, silicon, ceramic, quartz, glass, or plastic. A Fabry-Perot interference filter 10 is fixed to the plurality of support members 9 via heat-conducting members 15. Thus, the heat-absorbing region 50a of the temperature regulating element 50 is thermally connected to the Fabry-Perot interference filter 10 via the wiring board 7, the aforementioned heat-conducting members (not shown), the plurality of support members 9, and the heat-conducting members 15.

[0038] The heat-conducting member 15 serves not only as a heat-conducting member that transfers heat from the Fabry-Perot interference filter 10 to the support member 9, but also as an adhesive member that bonds the Fabry-Perot interference filter 10 to the support member 9. Similarly, the heat-conducting members (not shown) disposed between the wiring substrate 7 and each support member 9 serve not only as heat-conducting members that transfer heat from each support member 9 to the wiring substrate 7, but also as adhesive members that bond each support member 9 to the wiring substrate 7. The materials used for the heat-conducting member 15 and the aforementioned heat-conducting members (not shown) can be, for example, resin materials (e.g., silicone-based, urethane-based, epoxy-based, acrylic-based, or mixture-based resin materials, which can be conductive or non-conductive).

[0039] The Fabry-Perot interferometer filter 10 is disposed on line L. More specifically, the Fabry-Perot interferometer filter 10 is disposed such that the center line of its light transmission region 10a coincides with line L. Furthermore, the Fabry-Perot interferometer filter 10 may be supported by a single support member 9 instead of multiple support members 9. Alternatively, the Fabry-Perot interferometer filter 10 may be supported by a support member 9 integrally formed with the wiring substrate 7.

[0040] Multiple lead pins 11 are fixed to the tube socket 3. More specifically, each lead pin 11 penetrates the tube socket 3 while maintaining electrical insulation and airtightness with respect to the tube socket 3. The electrode pads, terminals of the temperature regulating element 50, terminals of the photodetector 8, terminals of the temperature compensation element, and terminals of the Fabry-Perot interference filter 10, which are provided on the wiring board 7, are each electrically connected to the lead pins 11 via leads 12. Thus, input and output of electrical signals to the temperature regulating element 50, the photodetector 8, the temperature compensation element, and the Fabry-Perot interference filter 10 can be performed.

[0041] An opening 2a is provided in the package 2. More specifically, the opening 2a is provided on the top wall 6 of the cover 4 with its center line aligned with line L. A light-transmitting member 13 is disposed on the inner surface 6a of the top wall 6 to close the opening 2a. That is, the light-transmitting member 13 is provided in the package 2 to close the opening 2a. The light-transmitting member 13 is hermetically bonded to the inner surface 6a of the top wall 6. The light-transmitting member 13 transmits light at least within the measurement wavelength range of the light detection device 1A. The light-transmitting member 13 is a plate-shaped member comprising a light incident surface 13a and a light exit surface 13b facing each other in a direction parallel to line L, and a side surface 13c. The light-transmitting member 13 is made of, for example, glass, quartz, silicon, germanium, plastic, etc. Compared with the material constituting the package 2, the light-transmitting member 13 is made of a material with low thermal conductivity. In addition, the plate-shaped light-transmitting member 13 can be fixed to the inner surface 6a of the top wall 6 by, for example, a thermally conductive adhesive member.

[0042] A bandpass filter 14 is provided on the light-emitting surface 13b of the light-transmitting member 13. The bandpass filter 14 is disposed on the light-emitting surface 13b of the light-transmitting member 13 by means of, for example, evaporation or attachment. The bandpass filter 14 selectively allows light within the measurement wavelength range of the photodetector 1A to pass through. The bandpass filter 14 is a dielectric multilayer film composed of a combination of high-refractive-index materials such as TiO2 and Ta2O5 and low-refractive-index materials such as SiO2 and MgF2.

[0043] In the photodetector 1A, the package 2 houses a temperature regulating element 50, a wiring board 7, a photodetector 8, a temperature compensation element (not shown), multiple support members 9, a heat conduction member 15, and a Fabry-Perot interference filter 10. The photodetector 8 is disposed on the heat-absorbing region 50a of the temperature regulating element 50 via the wiring board 7. The Fabry-Perot interference filter 10 is disposed on the heat-absorbing region 50a of the temperature regulating element 50 via the wiring board 7, multiple support members 9, and the heat conduction member 15, such that the photodetector 8 is located between the temperature regulating element 50 and the Fabry-Perot interference filter 10.

[0044] The photodetector 8 is located on one side of the line L relative to the Fabry-Perot interferometer filter 10 (here, the tube socket 3 side), and the heat-absorbing region 50a of the temperature regulating element 50 is located on one side of the line L relative to the photodetector 8 (here, the tube socket 3 side). The opening 2a of the package 2 and the light-transmitting member 13 are located on the other side of the line L relative to the Fabry-Perot interferometer filter 10 (the opposite side of one side) (here, the opposite side of the tube socket 3). In addition, the Fabry-Perot interferometer filter 10 and the light-transmitting member 13 are separated from each other by a gap.

[0045] The positional and size relationships of the various parts when viewed from a direction parallel to line L are as follows. For example... Figure 2 As shown, the center line of the light-receiving portion of the photodetector 8, the center line of the light-transmitting region 10a of the Fabry-Perot interferometer filter 10, and the center line of the opening 2a of the package 2 are aligned with line L. The outer edges of the light-transmitting region 10a of the Fabry-Perot interferometer filter 10 and the outer edges of the opening 2a of the package 2 are, for example, circular in shape. The outer edges of the photodetector 8 and the outer edges of the Fabry-Perot interferometer filter 10 are, for example, rectangular in shape.

[0046] The outer edge of the light-transmitting region 10a of the Fabry-Perot interferometer filter 10 is located outside the outer edge of the photodetector 8. The outer edge of the opening 2a of the package 2 is located outside the outer edge of the light-transmitting region 10a of the Fabry-Perot interferometer filter 10, and inside the outer edge of the Fabry-Perot interferometer filter 10. The outer edge of the light-transmitting member 13 is located outside the outer edge of the Fabry-Perot interferometer filter 10. The outer edge of the temperature regulating element 50 is located outside the outer edge of the Fabry-Perot interferometer filter 10. Furthermore, the phrase "when viewed from a predetermined direction, one outer edge is located outside the other outer edge" means "when viewed from a predetermined direction, one outer edge surrounds the other outer edge" or "when viewed from a predetermined direction, one outer edge contains the other outer edge." Conversely, the phrase "when viewed from a predetermined direction, one outer edge is located inside the other outer edge" means "when viewed from a predetermined direction, one outer edge is surrounded by the other outer edge" or "when viewed from a predetermined direction, one outer edge is contained by the other outer edge."

[0047] The details of the structure of the support member 9, the heat conduction member 15, and the Fabry-Perot interference filter 10 are described below. Figure 3 As shown (in) Figure 3 (The temperature control element 50, lead wire 12, tube socket 3, etc. are omitted). The Fabry-Perot interference filter 10 is supported by a pair of support members 9. When viewed from a direction parallel to line L, the pair of support members 9 are positioned opposite each other such that they sandwich the light-transmitting region 10a of the Fabry-Perot interference filter 10. On the mounting surface 9a of each support member 9, a portion of the light-transmitting region 10a in the bottom surface 10b of the Fabry-Perot interference filter 10 is placed, that is, a portion along a part of the side surface 10c of the Fabry-Perot interference filter 10. In this way, the support members 9 support the portion of the light-transmitting region 10a in the bottom surface 10b of the Fabry-Perot interference filter 10.

[0048] A portion of the side surface 10c of the Fabry-Perot interference filter 10 is positioned on the mounting surface 9a of each support member 9 such that a portion of the mounting surface 9a of each support member 9 is disposed on the outer side of this portion of the side surface 10c (the outer side of this portion of the side surface 10c when viewed from a direction parallel to line L). Thus, a corner C is formed by the portion of the side surface 10c and the portion of the mounting surface 9a of each support member 9 (the outer portion of this portion of the side surface 10c, i.e., the portion of the mounting surface 9a where the Fabry-Perot interference filter 10 is not mounted).

[0049] The heat-conducting member 15 is disposed along the corner C on the mounting surface 9a of each support member 9. In each mounting surface 9a of the support member 9, the heat-conducting member 15 includes a first portion 15a and a second portion 15b. The first portion 15a is disposed along the corner C. The second portion 15b is disposed between the mounting surface 9a of the support member 9 and the bottom surface 10b of the Fabry-Perot interference filter 10. Thus, the heat-conducting member 15 contacts a portion of the bottom surface 10b and a portion of the side surface 10c of the Fabry-Perot interference filter 10, as well as a portion of the mounting surface 9a of the support member 9. Furthermore, the first portion 15a reaches the side surface of the substrate 21 of the Fabry-Perot interference filter 10.

[0050] In the light detection device 1A configured as described above, such as Figure 1 As shown, if light from the outside passes through the opening 2a of the package 2, the light-transmitting member 13, and the bandpass filter 14 into the light-transmitting region 10a of the Fabry-Perot interferometer filter 10, light with a predetermined wavelength is selectively transmitted (details are described below). The light that has passed through the light-transmitting region 10a of the Fabry-Perot interferometer filter 10 is incident on the light-receiving part of the photodetector 8 and detected by the photodetector 8.

[0051] [Structure of a Fabry-Perot interferometer filter]

[0052] like Figure 4 As shown, in the Fabry-Perot interferometer filter 10, a light-transmitting region 10a, which allows light corresponding to the distance between the first and second mirrors to pass through, is provided on line L. In the light-transmitting region 10a, the distance between the first and second mirrors is controlled with extremely high precision. That is, the light-transmitting region 10a is a region in the Fabry-Perot interferometer filter 10 where the distance between the first and second mirrors can be controlled to a predetermined distance in order to selectively transmit light with a predetermined wavelength; it is a region where light with a predetermined wavelength corresponding to the distance between the first and second mirrors can pass through.

[0053] like Figure 5 As shown, the Fabry-Perot interferometer filter 10 includes a substrate 21. On the light-incident surface 21a of the substrate 21, an antireflective layer 31, a first laminate 32, an intermediate layer 33, and a second laminate 34 are stacked in this order. A gap (air gap) S is formed between the first laminate 32 and the second laminate 34 using a frame-shaped intermediate layer 33. The substrate 21 is made of, for example, silicon, quartz, or glass. When the substrate 21 is made of silicon, the antireflective layer 31 and the intermediate layer 33 are made of, for example, silicon oxide. The thickness of the intermediate layer 33 is preferably an integer multiple of half the center transmission wavelength (i.e., the center wavelength of the wavelength range that can pass through the Fabry-Perot interferometer filter 10).

[0054] The portion of the first laminate 32 corresponding to the light-transmitting region 10a functions as the first mirror 35. The first mirror 35 is supported by the substrate 21 via the anti-reflective layer 31. The first laminate 32 is constructed by alternately stacking multiple polysilicon layers and multiple silicon nitride layers every other layer. The optical thickness of each of the polysilicon layer and silicon nitride layer constituting the first mirror 35 is preferably an integer multiple of 1 / 4 of the center transmission wavelength. Alternatively, a silicon oxide layer may be used instead of a silicon nitride layer.

[0055] The portion of the second laminate 34 corresponding to the light-transmitting region 10a functions as a second mirror 36 opposite to the first mirror 35 via the gap S. The second mirror 36 is supported by the substrate 21 via the anti-reflective layer 31, the first laminate 32, and the intermediate layer 33. The second laminate 34 is constructed by alternately stacking multiple polysilicon layers and multiple silicon nitride layers every other layer. The optical thickness of each of the polysilicon and silicon nitride layers constituting the second mirror 36 is preferably an integer multiple of 1 / 4 of the center transmission wavelength. Alternatively, a silicon oxide layer may be used instead of a silicon nitride layer.

[0056] In the second layer stack 34, corresponding to the portion of the void S, a plurality of through holes (not shown) are provided extending from the surface 34a of the second layer stack 34 to the void S. The plurality of through holes are formed to a degree that does not substantially affect the function of the second mirror 36. The plurality of through holes are used to form the void S for removing a portion of the intermediate layer 33 by etching.

[0057] A first electrode 22 is formed on the first mirror 35 in a manner that surrounds the light-transmitting region 10a. A second electrode 23 is formed on the first mirror 35 in a manner that includes the light-transmitting region 10a. The first electrode 22 and the second electrode 23 are formed by doping impurities in a polycrystalline silicon layer and reducing its resistance. The size of the second electrode 23 is preferably the size that includes the entire light-transmitting region 10a, but it can be approximately the same as the size of the light-transmitting region 10a.

[0058] A third electrode 24 is formed on the second mirror 36. The third electrode 24 is opposite to the first electrode 22 and the second electrode 23 via a gap S in a direction parallel to line L. The third electrode 24 is formed by doping impurities in the polysilicon layer and reducing its resistance.

[0059] In the Fabry-Perot interference filter 10, the second electrode 23 is located on the opposite side of the third electrode 24 relative to the first electrode 22 in a direction parallel to line L. That is, the first electrode 22 and the second electrode 23 are not located on the same plane in the first mirror 35. The second electrode 23 is farther away from the third electrode 24 than the first electrode 22.

[0060] A pair of terminals 25 are arranged opposite each other, sandwiching the light-transmitting region 10a. Each terminal 25 is disposed in a through hole extending from the surface 34a of the second laminate 34 to the first laminate 32. Each terminal 25 is electrically connected to the first electrode 22 via a wiring 22a.

[0061] A pair of terminals 26 are arranged opposite each other, sandwiching the light-transmitting region 10a. Each terminal 26 is disposed in a through hole extending from the surface 34a of the second laminate 34 to the front of the intermediate layer 33. Each terminal 26 is electrically connected to the second electrode 23 via wiring 23a and to the third electrode 24 via wiring 24a. Furthermore, the orientation of the pair of terminals 25 is orthogonal to the orientation of the pair of terminals 26 (see reference). Figure 4 ).

[0062] Grooves 27 and 28 are provided on the surface 32a of the first laminate 32. Groove 27 extends in a ring shape surrounding the wiring 23a extending from terminal 26 in a direction parallel to line L. Groove 27 electrically insulates the first electrode 22 from the wiring 23a. Groove 28 extends in a ring shape along the inner edge of the first electrode 22. Groove 28 electrically insulates the first electrode 22 from the region inside the first electrode 22. The region within each groove 27 and 28 can be either an insulating material or a void.

[0063] A groove 29 is provided on the surface 34a of the second layer 34. The groove 29 extends in a ring shape to surround the terminal 25. The groove 29 electrically insulates the terminal 25 from the third electrode 24. The area within the groove 28 can be either an insulating material or a void.

[0064] On the light-emitting surface 21b of the substrate 21, the antireflective layer 41, the third laminate 42, the intermediate layer 43, and the fourth laminate 44 are stacked in this order. The antireflective layer 41 and the intermediate layer 43 have the same structure as the antireflective layer 31 and the intermediate layer 33. The third laminate 42 and the fourth laminate 44 have a stacked structure that is symmetrical with respect to the first laminate 32 and the second laminate 34 with the substrate 21 as a reference. The antireflective layer 41, the third laminate 42, the intermediate layer 43, and the fourth laminate 44 have the function of suppressing the warping of the substrate 21.

[0065] An opening 40a is provided in the antireflective layer 41, the third laminate 42, the intermediate layer 43, and the fourth laminate 44, such that it includes the light-transmitting region 10a. The opening 40a has a diameter approximately the same as the size of the light-transmitting region 10a. The opening 40a opens on the light-emitting side, and its bottom surface reaches the antireflective layer 41. A light-shielding layer 45 is formed on the light-emitting side surface of the fourth laminate 44. The light-shielding layer 45 is made of, for example, aluminum. A protective layer 46 is formed on the surface of the light-shielding layer 45 and the inner surface of the opening 40a. The protective layer 46 is made of, for example, aluminum oxide. Furthermore, by setting the thickness of the protective layer 46 to 100 nm (preferably around 30 nm), the optical effects of the protective layer 46 can be ignored.

[0066] In the Fabry-Perot interferometer filter 10 configured as described above, if a voltage is applied between the first electrode 22 and the third electrode 24 via terminals 25 and 26, an electrostatic force corresponding to that voltage is generated between the first electrode 22 and the third electrode 24. Using this electrostatic force, the second mirror 36 is attracted toward the first mirror 35 fixed to the substrate 21, and the distance between the first mirror 35 and the second mirror 36 is adjusted. Thus, in the Fabry-Perot interferometer filter 10, the distance between the first mirror 35 and the second mirror 36 is variable.

[0067] The wavelength of light passing through the Fabry-Perot interferometer filter 10 depends on the distance between the first mirror 35 and the second mirror 36 in the light transmission region 10a. Therefore, the wavelength of the transmitted light can be appropriately selected by adjusting the voltage applied between the first electrode 22 and the third electrode 24. At this time, the second electrode 23 and the third electrode 24 are at the same potential. Therefore, the second electrode 23 functions as a compensation electrode for keeping the first mirror 35 and the second mirror 36 flat in the light transmission region 10a.

[0068] In the light detection device 1A, a spectroscopic spectrum can be obtained by changing the voltage applied to the Fabry-Perot interferometer filter 10 (i.e., by changing the distance between the first mirror 35 and the second mirror 36 in the Fabry-Perot interferometer filter 10) while using the light detector 8 to detect the light passing through the light transmission region 10a of the Fabry-Perot interferometer filter 10.

[0069] [Functions and Effects]

[0070] In the light detection device 1A, the heat-absorbing region 50a of the temperature regulating element 50 is located on one side of the line L relative to the photodetector 8. Therefore, for example, compared to the case where the heat-absorbing region 50a of the temperature regulating element 50 is located to the side of the Fabry-Perot interference filter 10 and the photodetector 8 relative to the line L, the Fabry-Perot interference filter 10 and the photodetector 8 are cooled more uniformly. Specifically, the upper surface of the temperature regulating element 50 and the lower surface of the wiring substrate 7, the upper surface of the wiring substrate 7 and the lower surface of the photodetector 8, the upper surface of the wiring substrate 7 and the lower surface of the support member 9, and the upper surface of the support member 9 and the lower surface of the Fabry-Perot interference filter 10 are respectively in surface contact with each other via an adhesive or the like. Therefore, for example, compared to the case where the components are in point contact, cooling can be effectively achieved. Furthermore, on the line L, the Fabry-Perot interference filter 10 and the photodetector 8 are arranged between the light-transmitting member 13 and the heat-absorbing region 50a of the temperature regulating element 50. Therefore, condensation in the light-transmitting member 13, caused by excessive cooling of the light-transmitting member 13 and a large temperature difference between the light-transmitting member 13 and the outside air temperature (the operating ambient temperature of the photodetector 1A), can be suppressed. Thus, according to the photodetector 1A, condensation in the light-transmitting member 13 used to allow light to enter the package 2 can be suppressed, and the Fabry-Perot interferometer filter 10 and the photodetector 8 housed in the package 2 can be maintained at a uniform temperature.

[0071] Thus, in the photodetector 1A, since the Fabry-Perot interferometer filter 10 is uniformly cooled by the temperature regulating element 50, the temperature of the Fabry-Perot interferometer filter 10 can be maintained at a constant level regardless of the ambient temperature of the photodetector 1A. As a result, wavelength shift of transmitted light caused by changes in the ambient temperature of the photodetector 1A can be suppressed. Particularly in the Fabry-Perot interferometer filter 10, which has a first mirror 35 and a second mirror 36 with a variable distance between them, it is necessary to operate the thin-film second mirror 36 with extremely high precision and to control the distance between the first mirror 35 and the second mirror 36 with extremely high precision. Here, if the Fabry-Perot interferometer filter 10 has an uneven temperature across its components, it is difficult to control the distance between the first mirror 35 and the second mirror 36 with extremely high precision. Therefore, maintaining a uniform temperature for the Fabry-Perot interferometer filter 10 is very important. Furthermore, since the photodetector 8 is uniformly cooled by the temperature regulating element 50, the dark current generated in the photodetector 8 can be reduced.

[0072] Furthermore, compared to a structure where the temperature regulating element 50 is placed outside the package 2, the volume inside the package 2 is more likely to increase when the temperature regulating element 50 is placed inside the package 2. Therefore, in the structure where the temperature regulating element 50 is placed inside the package 2, due to the increased volume, it becomes correspondingly difficult to maintain a uniform temperature within the package 2. However, according to the structure of the photodetector 1A, the Fabry-Perot interferometer filter 10 and the photodetector 8, which have a significant impact on the accuracy of the measurement results, can be effectively maintained at a uniform temperature.

[0073] Here, the risk of condensation occurring in the light-transmitting member 13 is explained. First, if condensation occurs on the light-incident surface 13a and / or the light-exit surface 13b of the light-transmitting member 13, the amount of light incident into the package 2 will decrease, raising concerns about a reduction in the sensitivity of the photodetector 8. Furthermore, the light incident into the package 2 may experience multiple reflections, scattering, and lensing effects, becoming stray light, raising concerns about a decrease in the resolution and S / N ratio of the transmitted light incident into the photodetector 8. Therefore, if condensation occurs on the light-incident surface 13a and / or the light-exit surface 13b of the light-transmitting member 13, there is a concern about a decrease in the stability of the detection characteristics of the photodetector 8.

[0074] Furthermore, if condensation occurs on the second mirror 36 of the Fabry-Perot interferometer filter 10, there is a concern that the peak wavelength of the transmitted light may change relative to the control voltage applied to the Fabry-Perot interferometer filter 10. Moreover, there is a concern that moisture may cause the first mirror 35 and the second mirror 36 to adhere to each other, leading to malfunctions.

[0075] In contrast, the aforementioned risks are avoided in the light detection device 1A because condensation in the light-transmitting member 13 can be suppressed. Especially in cases where moisture remains inside the package 2 during manufacturing, the structure of the light detection device 1A, which suppresses condensation in the light-transmitting member 13, is effective. Furthermore, since the structure of the light detection device 1A suppresses condensation in the light-transmitting member 13, the distance between the components can be reduced, thus miniaturizing the light detection device 1A.

[0076] In the light detection device 1A, when viewed from a direction parallel to line L, the outer edge of the opening 2a of the package 2 is located inside the outer edge of the Fabry-Perot interference filter 10, and the heating region 50b of the temperature regulating element 50 is thermally connected to the package 2. Therefore, for example, compared to the case where the outer edge of the opening 2a is located outside the outer edge of the Fabry-Perot interference filter 10, heat is more easily transferred via the package 2 between the heating region 50b of the temperature regulating element 50 and the light-transmitting member 13 (specifically, heat is easily transferred from the heating region 50b of the temperature regulating element 50 to the light-transmitting member 13 via the package 2). Thus, condensation in the light-transmitting member 13 can be more reliably suppressed.

[0077] In the light detection device 1A, when viewed from a direction parallel to line L, the outer edge of the light-transmitting member 13 is located outside the outer edge of the Fabry-Perot interference filter 10. Therefore, compared to the case where the outer edge of the light-transmitting member 13 is located inside the outer edge of the Fabry-Perot interference filter 10, the contact area between the light-transmitting member 13 and the package 2 is increased, and heat is easily transferred between the light-transmitting member 13 and the package 2 (specifically, heat is easily transferred from the heating area 50b of the temperature regulating element 50 to the light-transmitting member 13 via the package 2). Furthermore, in the light detection device 1A, since the side surface 13c of the light-transmitting member 13 contacts the package 2, the contact area between the light-transmitting member 13 and the package 2 becomes larger. Therefore, condensation in the light-transmitting member 13 can be suppressed more reliably. Moreover, according to this structure, even if the lead 12 connected to the Fabry-Perot interference filter 10 is bent, the insulating light-transmitting member 13 can prevent the lead 12 from contacting the package 2. This prevents the electrical signal used to control the Fabry-Perot interferometer filter 10 from flowing to the package 2, thus enabling high-precision control of the Fabry-Perot interferometer filter 10.

[0078] In the photodetector 1A, a temperature regulating element 50 is disposed within the package 2, a photodetector 8 is disposed on the temperature regulating element 50, and a Fabry-Perot interferometer filter 10 is disposed on the temperature regulating element 50 such that the photodetector 8 is located between the temperature regulating element 50 and the Fabry-Perot interferometer filter 10. Thus, a small and simple structure can efficiently maintain the Fabry-Perot interferometer filter 10 and the photodetector 8 at a uniform temperature.

[0079] As an example, in the direction parallel to line L, the thickness of the temperature regulating element 50 is 0.7–2 mm, the thickness of the wiring substrate 7 is 0.3 mm, the thickness of the support member 9 is 0.6 mm, and the thickness of the Fabry-Perot interference filter 10 is 0.6 mm. Furthermore, the height of the portion protruding from the upper surface of the tube seat 3 in the lead pin 11 is 0.2–1 mm, for example, 0.5 mm. That is, the temperature regulating element 50 is thicker than each of the wiring substrate 7, the support member 9, and the Fabry-Perot interference filter 10. Because the temperature regulating element 50 is thick, the photodetector 8 and the Fabry-Perot interference filter 10 are less susceptible to the heat emitted from the self-heating region 50b. On the other hand, because the wiring substrate 7, the support member 9, and the Fabry-Perot interference filter 10 are thin, the cooling of the heat-absorbing region 50a can be effectively achieved.

[0080] Furthermore, in the photodetector 1A, the upper surface of the lead pin 11 is located lower than the upper surfaces of the temperature control element 50, the wiring board 7, the support member 9, and the Fabry-Perot interferometer filter 10. This facilitates the connection of the lead 12 from the photodetector 8 and the Fabry-Perot interferometer filter 10 to the lead pin 11 (especially suppressing interference between the lead 12 extending from the photodetector 8 and the temperature compensation element positioned above the Fabry-Perot interferometer filter 10 and the Fabry-Perot interferometer filter 10).

[0081] Furthermore, considering the ease of connecting the lead 12 from the Fabry-Perot interference filter 10 to the lead pin 11, it is preferable that the height of the Fabry-Perot interference filter 10 from the tube socket 3 should not be too high. Therefore, from the viewpoint of connecting the lead from the lead to the lead pin 11, the structure in which the temperature regulating element 50 is arranged under the stack of the wiring board 7, the support member 9, and the Fabry-Perot interference filter 10 is not preferred because the height of the Fabry-Perot interference filter 10 from the tube socket 3 becomes higher. However, in the photodetector 1A, by keeping the thickness of the wiring board 7, the support member 9, and the Fabry-Perot interference filter 10 thin, the height of the Fabry-Perot interference filter 10 from the tube socket 3 is suppressed, thus minimizing the disadvantages.

[0082] In the photodetector 1A, the Fabry-Perot interferometer filter 10 and the light-transmitting member 13 are separated from each other by a gap. This suppresses the influence of the ambient temperature of the photodetector 10 on the Fabry-Perot interferometer filter 10, as well as the heat from the package 2 and the light-transmitting member 13. Specifically, in the photodetector 1A, the volume of the upper space of the Fabry-Perot interferometer filter 10 (the space between the upper surface of the Fabry-Perot interferometer filter 10 and the light-emitting surface 13b of the light-transmitting member 13) is larger than the volume of the lower space of the Fabry-Perot interferometer filter 10 (the space between the lower surface of the Fabry-Perot interferometer filter 10 and the upper surface of the wiring substrate 7). Therefore, heat transfer between the Fabry-Perot interferometer filter 10 and the light-transmitting member 13 can be effectively suppressed.

[0083] The photodetector 1A includes: a support member 9 that supports the outer portion of the light-transmitting region 10a in the bottom surface 10b of the Fabry-Perot interferometer filter 10; and a heat-conducting member 15 that contacts the side surface 10c of the Fabry-Perot interferometer filter 10 and the support member 9. Therefore, compared to the case where the heat-conducting member 15 is not provided and contacts the side surface 10c of the Fabry-Perot interferometer filter 10 and the support member 9, heat is easily transferred via the support member 9 between the Fabry-Perot interferometer filter 10 and the heat-absorbing region 50a of the temperature regulating element 50 (specifically, heat is easily transferred from the Fabry-Perot interferometer filter 10 to the heat-absorbing region 50a of the temperature regulating element 50). Thus, the Fabry-Perot interferometer filter 10 and the photodetector 8 can be maintained at a uniform temperature efficiently.

[0084] In the optical detection device 1A, the heat conduction member 15 is an adhesive member that bonds the Fabry-Perot interference filter 10 to the support member 9. This ensures the stable holding state of the Fabry-Perot interference filter 10 on the support member 9.

[0085] In the photodetector 1A, the heat-conducting member 15 is disposed at corner C, contacting a portion of the side surface 10c of the Fabry-Perot interferometer filter 10 and a portion of the mounting surface 9a of the support member 9, respectively. This allows for more efficient maintenance of a uniform temperature for the Fabry-Perot interferometer filter 10 and the photodetector 8, and more reliably stabilizes the position of the Fabry-Perot interferometer filter 10 on the support member 9. In particular, disposing the heat-conducting member 15 at corner C increases its volume and stabilizes its orientation, making it effective.

[0086] [Second Implementation]

[0087] [Structure of the optical detection device]

[0088] like Figure 6 As shown, the photodetector 1B differs from the photodetector 1A described above in that it is configured as an SMD (Surface Mount Device). The photodetector 1B includes a main body 200 that constitutes a package 2 housing the photodetector 8 and the Fabry-Perot interference filter 10. The main body 200 can be made of materials such as ceramic or resin. Multiple wirings (not shown) are laid on the main body 200. Multiple mounting electrode pads 207 are provided on the bottom surface 200a of the main body 200. Corresponding wirings (not shown) are electrically connected to the mounting electrode pads 207.

[0089] The main body 200 has a first widened portion 201, a second widened portion 202, a third widened portion 203, a fourth widened portion 204, and a recess 205. The recess 205, the fourth widened portion 204, the third widened portion 203, the second widened portion 202, and the first widened portion 201 are arranged in this order from the bottom surface 200a side with a straight line, i.e., a predetermined line L, as the center line, and form a space that opens on the opposite side of the bottom surface 200a.

[0090] A photodetector 8 is fixed to the bottom surface of the recess 205. The bottom surface of the recess 205 and the bottom surface of the photodetector 8 are bonded together via, for example, a thermally conductive adhesive member (not shown). The photodetector 8 is disposed on line L. More specifically, the photodetector 8 is disposed such that the center line of its light-receiving portion coincides with line L. On the bottom surface of the third widened portion 203, a Fabry-Perot interference filter 10 is fixed via a thermally conductive member 15. That is, the bottom surface of the third widened portion 203 and the bottom surface 10b of the Fabry-Perot interference filter 10 are bonded together via the thermally conductive member 15. The Fabry-Perot interference filter 10 is disposed on line L. More specifically, the Fabry-Perot interference filter 10 is disposed such that the center line of its light-transmitting region 10a coincides with line L. On the bottom surface of the first widened portion 201, a plate-shaped light-transmitting member 13 is fixed, for example, via a thermally conductive adhesive member. A bandpass filter 14 is provided on the light-emitting surface 13b of the light-transmitting member 13. In addition, a temperature compensation element (not shown) is embedded in the main body 200.

[0091] The terminals of the photodetector 8, the temperature compensation element, and the Fabry-Perot interferometer filter 10 are each electrically connected to their corresponding mounting electrode pads 207 via leads 12 and wiring (not shown), or simply via wiring (not shown). This allows for the input and output of electrical signals to the photodetector 8, the temperature compensation element, and the Fabry-Perot interferometer filter 10.

[0092] Furthermore, a temperature regulating element 50 is embedded in a predetermined portion of the main body 200, which serves as the wall of the package 2. More specifically, the temperature regulating element 50 is embedded in the entire portion of the main body 200, including the portion between the bottom surface of the recess 205 and the bottom surface 200a of the main body 200, the portion between the bottom surface of the fourth widening portion 204 and the bottom surface 200a of the main body 200, and the portion between the bottom surface of the third widening portion 203 and the bottom surface 200a of the main body 200.

[0093] The temperature regulating element 50 is, for example, a Peltier element. In the temperature regulating element 50, a plurality of N-type semiconductor layers 51 and a plurality of P-type semiconductor layers 52 are arranged alternately. All the alternately arranged N-type semiconductor layers 51 and P-type semiconductor layers 52 are connected in series, and the ends of the bottom surface 200a of adjacent N-type semiconductor layers 51 and P-type semiconductor layers 52 are connected to each other via a first metal member 53, and the ends of the bottom surface 200a of adjacent N-type semiconductor layers 51 and P-type semiconductor layers 52 are connected to each other via a second metal member 54.

[0094] When considering the N-type semiconductor layer 51 and the P-type semiconductor layer 52 connected to each other by the first metal member 53, if a current flows from the N-type semiconductor layer 51 toward the P-type semiconductor layer 52, heat absorption occurs in the first metal member 53. Therefore, the bottom surface of the third widened portion 203, the bottom surface of the fourth widened portion 204, and the bottom surface of the recess 205 function as heat-absorbing regions 50a.

[0095] When considering the P-type semiconductor layer 52 and the N-type semiconductor layer 51 connected to each other by the second metal member 54, if a current flows from the P-type semiconductor layer 52 toward the N-type semiconductor layer 51, heat will be generated in the second metal member 54. As a result, the bottom surface 200a of the main body 200 functions as the heat-generating area 50b.

[0096] The terminals of the temperature regulating element 50 are electrically connected to the corresponding mounting electrode pads 207 via wiring (not shown). This allows for input and output of electrical signals to the temperature regulating element 50. In the temperature regulating element 50, all alternately arranged N-type semiconductor layers 51 and P-type semiconductor layers 52 are connected in series. Therefore, if a current flows in a predetermined direction, current flows from the N-type semiconductor layer 51 to the P-type semiconductor layer 52 in the first metal member 53, and the bottom surfaces of the third widened portion 203, the fourth widened portion 204, and the recess 205 function as heat-absorbing regions 50a. On the other hand, current flows from the P-type semiconductor layer 52 to the N-type semiconductor layer 51 in the second metal member 54, and the bottom surface 200a of the main body 200 functions as a heat-generating region 50b.

[0097] In the photodetector 1B, the package 2 houses the photodetector 8, the heat-conducting member 15, and the Fabry-Perot interferometer filter 10. A temperature compensation element (not shown) and a temperature regulating element 50 are embedded in the wall of the package 2. The photodetector 8 is disposed on the bottom surface of the heat-absorbing region 50a, i.e., the recess 205, of the temperature regulating element 50. The bottom surface of the heat-absorbing region 50a, i.e., the recess 205, is thermally connected to the photodetector 8. The Fabry-Perot interferometer filter 10 is disposed via the heat-conducting member 15 on the bottom surface of the heat-absorbing region 50a, i.e., the third widened portion 203, of the temperature regulating element 50, with the photodetector 8 located between the temperature regulating element 50 and the Fabry-Perot interferometer filter 10. The bottom surface of the heat-absorbing region 50a, i.e., the third widened portion 203, is thermally connected to the Fabry-Perot interferometer filter 10.

[0098] A heat sink 60 is bonded to the bottom surface 200a of the main body 200, i.e., the heating area 50b of the temperature regulating element 50, via a bonding member with good thermal conductivity, for example. This allows heat generated in the self-heating area 50b to be effectively dissipated via the heat sink 60. If the heat sink 60 is thicker than the electrode pad 207, the photodetector 1B can be mounted on the external wiring board where a through hole is pre-formed to prevent interference from the heat sink 60. Alternatively, the electrode pad 207 can be placed on the side of the main body 200 without a through hole on the external wiring board, and the photodetector 1B can be mounted with the line L approximately horizontal to the surface of the external wiring board. Alternatively, a metal plate thinner than the electrode pad 207 can be bonded to the bottom surface 200a of the main body 200 to serve as the heat sink 60. In this case, if the metal plate is made of the same material as the electrode pad 207 (e.g., gold, silver, copper, aluminum, tungsten, etc.), the forming process towards the bottom surface 200a can be performed simultaneously.

[0099] The photodetector 8 is located on one side of the Fabry-Perot interference filter 10 along line L (here, the bottom surface 200a side of the main body 200), and the bottom surface of the heat-absorbing region 50a of the temperature regulating element 50, i.e., the recess 205, is located on one side of the photodetector 8 along line L (here, the bottom surface 200a side of the main body 200). The opening of the package 2 (the first widened portion 201) and the light-transmitting member 13 are located on the other side of the Fabry-Perot interference filter 10 along line L (the opposite side of one side) (here, the opposite side of the bottom surface 200a of the main body 200). In addition, the Fabry-Perot interference filter 10 and the light-transmitting member 13 are separated from each other by a gap.

[0100] In the optical detection device 1B, a heat-conducting member 15 is disposed on the bottom surface of the third widened portion 203 such that it aligns with the gap between the side surface of the Fabry-Perot interference filter 10 and the inner surface of the third widened portion 203. The heat-conducting member 15 includes: a first portion disposed along the gap between the side surface of the Fabry-Perot interference filter 10 and the inner surface of the third widened portion 203; and a second portion disposed between the bottom surface of the third widened portion 203 and the bottom surface of the Fabry-Perot interference filter 10. Thus, the heat-conducting member 15 contacts a portion of the bottom surface and a portion of the side surface of the Fabry-Perot interference filter 10, as well as the bottom surface of the third widened portion 203. Furthermore, the first portion extends to the side surface of the substrate 21 of the Fabry-Perot interference filter 10.

[0101] In the light detection device 1B configured as described above, when light from the outside is incident on the light transmission region 10a of the Fabry-Perot interferometer filter 10 through the opening (first widened portion 201) of the package 2, the light transmission member 13, and the bandpass filter 14, light with a predetermined wavelength is selectively transmitted, corresponding to the distance between the first mirror 35 and the second mirror 36 in the light transmission region 10a. The light that has passed through the light transmission region 10a of the Fabry-Perot interferometer filter 10 is incident on the light receiving portion of the photodetector 8 and detected by the photodetector 8. In the light detection device 1B, by changing the voltage applied to the Fabry-Perot interferometer filter 10 (i.e., by changing the distance between the first mirror 35 and the second mirror 36 in the Fabry-Perot interferometer filter 10), and by detecting the light that has passed through the light transmission region 10a of the Fabry-Perot interferometer filter 10 using the photodetector 8, a spectroscopic spectrum can be obtained.

[0102] [Functions and Effects]

[0103] In the light detection device 1B, the bottom surface of the recess 205 in the heat-absorbing region 50a of the temperature regulating element 50 is located on one side of the line L relative to the photodetector 8. Furthermore, the bottom surface of the third widened portion 203 in the heat-absorbing region 50a of the temperature regulating element 50 is located on one side relative to the Fabry-Perot interference filter 10. Therefore, the Fabry-Perot interference filter 10 and the photodetector 8 are cooled uniformly. In particular, the bottom surface of the recess 205 and the lower surface of the photodetector 8, as well as the bottom surface of the third widened portion 203 and the lower surface of the Fabry-Perot interference filter 10, are in surface contact with each other via an adhesive or the like. This allows for more efficient cooling compared to situations where the components are in point contact. Furthermore, the Fabry-Perot interference filter 10 and the photodetector 8 are arranged on the line L between the light-transmitting member 13 and the bottom surface of the recess 205. Furthermore, a Fabry-Perot interference filter 10 is disposed between the light-transmitting member 13 and the bottom surface of the third widened portion 203. This suppresses condensation in the light-transmitting member 13 caused by excessive cooling, which increases the temperature difference between the light-transmitting member 13 and the outside air temperature (the operating ambient temperature of the photodetector 1B). Therefore, according to this photodetector 1B, condensation in the light-transmitting member 13 used to direct light into the package 2 can be suppressed, and the Fabry-Perot interference filter 10 and the photodetector 8 housed in the package 2 can be maintained at a uniform temperature.

[0104] In the optical detection device 1B, the heat conduction member 15 is an adhesive member that bonds the Fabry-Perot interference filter 10 to the main body 200. This stabilizes the holding state of the Fabry-Perot interference filter 10 in the third widened portion 203 of the main body 200.

[0105] In the photodetector 1B, the heat-conducting member 15 is disposed on the bottom surface of the third widened portion 203 such that it aligns with the gap between the side surface of the Fabry-Perot interference filter 10 and the inner surface of the third widened portion 203, respectively contacting a portion of the side surface of the Fabry-Perot interference filter 10 and the bottom surface of the third widened portion 203. This allows for more efficient maintenance of a uniform temperature for the Fabry-Perot interference filter 10 and the photodetector 8, and more reliably stabilizes the holding state of the Fabry-Perot interference filter 10 in the third widened portion 203 of the main body 200.

[0106] In the photodetector 1B, the temperature regulating element 50 is embedded in the wall of the package 2. This reduces the volume of space within the package 2, resulting in a more efficient maintenance of a uniform temperature for the Fabry-Perot interferometer filter 10 and the photodetector 8.

[0107] [Variation Example]

[0108] The first and second embodiments of the present invention have been described above, but the photodetector of the present invention is not limited to the first and second embodiments described above. For example, the materials and shapes of each structure are not limited to the materials and shapes described above, and various materials and shapes can be used.

[0109] In addition, such as Figure 7 As shown, as a variation of the light detection device 1B in the second embodiment, an annular groove 206 surrounding the temperature regulating element 50, the photodetector 8, the heat conduction member 15, and the Fabry-Perot interference filter 10 can also be formed in the main body 200. According to this structure, the temperature regulating element 50, the photodetector 8, the heat conduction member 15, and the Fabry-Perot interference filter 10 can be thermally separated, resulting in more efficient maintenance of a uniform temperature for the Fabry-Perot interference filter 10 and the photodetector 8.

[0110] In addition, such as Figure 8 As shown, as a variation of the light detection device 1B in the second embodiment, the terminals of the Fabry-Perot interferometer filter 10 and the light detector 8 may be connected to the wiring laid on the main body 200 by the bump 16 (not shown). According to this structure, since the lead wire 12 is not required, the light detection device 1B can be miniaturized.

[0111] Furthermore, in both the light detection device 1A of the first embodiment and the light detection device 1B of the second embodiment, the bandpass filter 14 can be disposed on the light incident surface 13a of the light transmitting member 13, or on both the light incident surface 13a and the light exit surface 13b of the light transmitting member 13.

[0112] Furthermore, in both the light detection device 1A of the first embodiment and the light detection device 1B of the second embodiment, the Fabry-Perot interferometer filter 10 may not have the laminated structure (anti-reflection layer 41, third laminate 42, intermediate layer 43, fourth laminate 44, light-shielding layer 45, and protective layer 46) provided on the light-emitting side of the substrate 21. Alternatively, it may only have a portion of the layers (for example, only the anti-reflection layer 41 and the protective layer 46) as needed.

[0113] Furthermore, in both the light detection device 1A of the first embodiment and the light detection device 1B of the second embodiment, the outer edge of the light transmission region 10a of the Fabry-Perot interference filter 10 may be located outside the outer edge of the opening 2a when viewed from a direction parallel to line L. In this case, the proportion of light entering the light transmission region 10a from the light incident from the opening 2a increases, and the utilization efficiency of the light incident from the opening 2a is improved. Moreover, even with a slight offset from the position of the opening 2a relative to the light transmission region 10a, the positional accuracy requirements during the assembly of the light detection devices 1A and 1B are somewhat alleviated because light incident from the opening 2a enters the light transmission region 10a.

[0114] Furthermore, in both the light detection device 1A of the first embodiment and the light detection device 1B of the second embodiment, if the heat conduction member 15 includes the first part 15a, then the second part 15b may not be included. The heat conduction member 15 is not limited to the material described above, and may be a metal such as solder.

[0115] Furthermore, in both the light detection device 1A of the first embodiment and the light detection device 1B of the second embodiment, the heat-absorbing region 50a of the temperature regulating element 50 can be thermally connected to the Fabry-Perot interferometer 10 either through direct contact or via certain components. Similarly, the heat-absorbing region 50a of the temperature regulating element 50 can be thermally connected to the photodetector 8 either through direct contact or via certain components.

[0116] Furthermore, in the photodetector 1A of the first embodiment, the heating area 50b of the temperature regulating element 50 can be thermally connected to the package 2 either by direct contact with the package 2 or by thermal connection to the package 2 via certain components.

[0117] Furthermore, in both the light detection device 1A of the first embodiment and the light detection device 1B of the second embodiment, the light detector 8 can be directly disposed on the temperature regulating element 50 or disposed on the temperature regulating element 50 via certain components.

[0118] Furthermore, in both the light detection device 1A of the first embodiment and the light detection device 1B of the second embodiment, a temperature regulating element 50 is used for the purpose of cooling the interior of the package 2. This is effective when the ambient temperature of the light detection devices 1A and 1B is higher than the set temperature (appropriate operating temperature) of the Fabry-Perot interferometer filter 10 and the photodetector 8. Conversely, when the ambient temperature of the light detection devices 1A and 1B is lower than the set temperature of the Fabry-Perot interferometer filter 10 and the photodetector 8, the temperature regulating element 50 can be used for the purpose of heating the interior of the package 2. That is, in the temperature regulating element 50, the region that functions as a heat-absorbing region 50a (the first region thermally connected to the Fabry-Perot interferometer filter 10 and the photodetector 8) can function as a heat-generating region 50b, and the region that functions as a heat-generating region 50b (the second region thermally connected to the package 2 in the light detection device 1A of the first embodiment) can function as a heat-absorbing region 50a. Therefore, even when the operating ambient temperature of the photodetectors 1A and 1B is low, the Fabry-Perot interferometer filter 10 and the photodetector 8 housed in the package 2 can be maintained at a uniform temperature, and in particular, wavelength shift of transmitted light caused by changes in the operating ambient temperature of the photodetectors 1A and 1B can be suppressed. Furthermore, damage to the light-transmitting member 13 caused by excessive heating, resulting in a large temperature difference between the light-transmitting member 13 and the outside air temperature (the operating ambient temperature of the photodetectors 1A and 1B), can be suppressed (such as cracks caused by stress difference between the light-incident surface 13a, which contracts due to low outside air temperature, and the light-exit surface 13b, which expands due to heating). Additionally, if a Peltier element is used as the temperature regulating element 50, the heat-absorbing region and the heat-generating region can be easily switched by changing the direction of current flow in the Peltier element.

[0119] Explanation of symbols

[0120] 1A, 1B…light detection device, 2…package, 2a…opening, 8…light detector, 9…support member, 9a…mounting surface, 10…Fabry-Perot interference filter, 10a…light transmission area, 10b…bottom surface, 10c…side surface, 13…light transmission member, 15…heat conduction member, 35…first mirror, 36…second mirror, 50…temperature regulation element, 50a…heat absorption area, 50b…heat generation area, C…corner, L…line.

Claims

1. A light detection device, characterized in that, have: A Fabry-Perot interference filter has a first mirror and a second mirror whose distance from each other is variable, and a light-transmitting region is provided on a predetermined line so that light corresponding to the distance between the first mirror and the second mirror can pass through. A photodetector, disposed on one side of the line relative to the Fabry-Perot interferometer filter, detects light that has passed through the light-transmitting region; A package having an opening on the line opposite to the Fabry-Perot interferometer filter, and housing the Fabry-Perot interferometer filter and the photodetector; and A temperature regulating element is thermally connected to the Fabry-Perot interferometer filter and the photodetector, and cools or heats the Fabry-Perot interferometer filter and the photodetector. The photodetector is disposed on the bottom surface of a recess formed in the package. The Fabry-Perot interference filter is disposed on the bottom surface of the widened portion formed in the package body in such a manner that it is located on the other side relative to the recess. The temperature regulating element is embedded in the wall of the package body at least in the portion corresponding to the bottom surface of the recess and the portion corresponding to the bottom surface of the widened portion. The temperature regulating element has: Region 1, which is thermally connected to the Fabry-Perot interferometer filter and the photodetector, and functions as one of the heat-absorbing and heat-generating regions; and The second region is thermally connected to the package and functions as the other of the heat-absorbing and heat-generating regions. In the portion corresponding to the bottom surface of the recess, the first region is located on the bottom surface side of the recess, and the second region is located on the opposite side of the bottom surface of the recess. A portion of the temperature regulating element is located within the wall of the package body, which is the portion corresponding to the bottom surface of the widened portion, on the side where the opening is located relative to the bottom surface of the recess.

2. The optical detection device as described in claim 1, characterized in that, It also includes a light-transmitting member disposed in the package in a manner that closes the opening.

3. The optical detection device as described in claim 1 or 2, characterized in that, It also includes a heat-conducting member disposed between the Fabry-Perot interference filter and the widening portion and in contact with the Fabry-Perot interference filter and the widening portion.

4. The optical detection device as described in claim 3, characterized in that, The heat-conducting component includes a first part. The first part is disposed between the side surface of the Fabry-Perot interferometer filter and the inner surface of the widened portion and contacts the side surface of the Fabry-Perot interferometer filter and the inner surface of the widened portion.

5. The optical detection device as described in claim 3 or 4, characterized in that, The heat-conducting component includes a second part. The second part is disposed between the bottom surface of the Fabry-Perot interference filter and the bottom surface of the widened portion and is in contact with the bottom surface of both the Fabry-Perot interference filter and the bottom surface of the widened portion.

6. The light detection device as described in any one of claims 3 to 5, characterized in that, The heat-conducting component is an adhesive component that bonds the Fabry-Perot interference filter to the widened portion.

7. The light detection device according to any one of claims 1 to 6, characterized in that, It also includes a heat sink installed on the outer surface of the package body in a region opposite to the bottom surface of the recess.

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