Light detection device and aperture part

Abstract

A light detection device is provided with: a package having an opening; a light transmissive portion that blocks the opening and has a light emission surface located within the package; a Fabry-Perot interference filter including a pair of mirror parts with a variable distance from each other; a light detector; and a first aperture part having a first aperture positioned between the light emission surface and the Fabry-Perot interference filter within the package. The first aperture portion includes a first surrounding portion surrounding the first aperture. A surface on the Fabry-Perot interference filter side in the first surrounding portion is separated from the Fabry-Perot interference filter and has light absorptivity.

Description

Technical Field

[0001] The present invention relates to a light detection device and an aperture unit including a Fabry-Perot interference filter. Background Art

[0002] There is known a light detection device, which includes: a package having an opening; a light transmission portion that blocks the opening; a Fabry-Perot interference filter that is disposed in the package and includes a pair of mirror portions whose distance from each other is variable; and a light detector that is disposed in the package (for example, see Patent Document 1). In such a light detection device, in the Fabry-Perot interference filter, the distance between the pair of mirror portions is changed, and the light that has passed through the pair of mirror portions among the light incident through the light transmission portion is detected by the light detector, thereby obtaining a spectroscopic spectrum of the light to be measured.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-141713 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the above-mentioned light detection device, how to suppress stray light (for example, light that has not passed through a pair of mirrors, light that has obliquely passed through a pair of mirrors) from entering the light detector is extremely important for improving the S / N ratio in wavelength analysis of the light to be measured.

[0008] An object of the present invention is to provide a light detection device and an aperture unit capable of suppressing stray light from entering a light detector.

[0009] Technical means of solving problems

[0010] According to one aspect of the present invention, a light detection device is as follows: [1] "a light detection device comprising: a package having an opening; a light transmitting portion blocking the opening and having a light emitting surface located in the package; a Fabry-Perot interference filter arranged in the package on the side opposite to the opening relative to the light emitting surface, and including a pair of mirror portions whose mutual distance is variable; a light detector arranged in the package on the side opposite to the opening relative to the Fabry-Perot interference filter; and a first aperture portion having a first aperture located in the package between the light emitting surface and the Fabry-Perot interference filter, the first aperture portion including a first surrounding portion surrounding the first aperture, a surface of the first surrounding portion on the Fabry-Perot interference filter side being separated from the Fabry-Perot interference filter and having light absorption".

[0011] In the light detection device described in [1] above, the first aperture is located between the light exit surface of the light transmission portion and the Fabry-Perot interference filter. As a result, light incident on the opening at a large incident angle is difficult to travel into the space on the Fabry-Perot interference filter side. Furthermore, in the light detection device described in [1] above, the surface on the Fabry-Perot interference filter side in the first surrounding portion surrounding the first aperture is separated from the Fabry-Perot interference filter and has light absorption. As a result, light reflected on the inner surface of the package through the first aperture is incident on the surface on the Fabry-Perot interference filter side in the first surrounding portion and is easily attenuated on this surface. Therefore, according to the light detection device described in [1] above, it is possible to suppress stray light from being incident on the light detector.

[0012] The light detection device according to one aspect of the present invention may be [2] "the light detection device according to [1] above, wherein the outer edge of the first aperture is located on the inner side of the outer edge of the opening when viewed from the relative direction of the pair of mirror portions". According to the light detection device described in [2], since the incident angle of the light entering the pair of mirror portions through the opening and the first aperture becomes smaller, the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured.

[0013] The light detection device according to one aspect of the present invention may be [3] "the light detection device according to [1] or [2] above, wherein the light transmission section includes a light transmission component that blocks the opening, and a bandpass filter that is arranged on the side opposite to the opening relative to the light transmission component." According to the light detection device described in [3], since light in a predetermined wavelength range can be incident on the pair of mirrors, the S / N ratio and resolution can be improved in the wavelength analysis of the light to be measured.

[0014] The light detection device according to one aspect of the present invention may be [4] "the light detection device according to [1] or [2] above, wherein the light transmission portion is a light transmission component that blocks the opening". According to the light detection device described in [4], the structure of the light transmission portion can be simplified.

[0015] The light detection device according to one aspect of the present invention may be [5] "a light detection device according to any one of [1] to [4] above, wherein the first aperture section is a plate-shaped first surrounding portion fixed to at least one of the package and the light transmitting section". According to the light detection device described in [5], the first aperture can be located at a predetermined position while simplifying the structure of the first aperture section.

[0016] The light detection device of one aspect of the present invention may also be, [6] "the light detection device according to the above [5], wherein the positioning of the first aperture portion in a direction perpendicular to the relative direction of the pair of mirror portions is performed by the first surrounding portion and the package." According to the light detection device described in [6], when manufacturing the light detection device, the center line of the first aperture can be aligned with the center line of the opening by passive alignment.

[0017] The light detection device according to one aspect of the present invention may be, [7] "a light detection device according to [5] or [6] above, wherein the first aperture portion is positioned in the relative direction of the pair of mirror portions by the first surrounding portion and the light transmitting portion". According to the light detection device described in [7], when manufacturing the light detection device, the distance between the opening and the first aperture can be set to a predetermined distance by passive alignment.

[0018] The light detection device of one aspect of the present invention may be [8] "the light detection device according to any one of [1] to [4] above, wherein the first aperture section is the first film-shaped surrounding portion formed on the light emitting surface." According to the light detection device described in [8], the first aperture section can be located at a predetermined position while simplifying the structure of the first aperture section.

[0019] The light detection device according to one aspect of the present invention may be, [9] "a light detection device according to any one of [1] to [4] above, wherein the first aperture portion further includes a support portion in the package that supports the first surrounding portion". According to the light detection device described in [9], the first aperture can be located at a predetermined position regardless of the shape of the package.

[0020] The light detection device of one aspect of the present invention may be

[10] "a light detection device according to any one of [1] to [9] above, further comprising a light absorbing film formed on the inner surface of the package". According to the light detection device described in

[10] , stray light can be attenuated not only on the surface on the Fabry-Perot interference filter side in the first enclosure but also on the inner surface of the package.

[0021] The light detection device of one aspect of the present invention may also be

[11] "a light detection device according to any one of [1] to

[10] above, further comprising: a second aperture portion having a second aperture located on the side opposite to the light emitting surface relative to the opening outside the package". According to the light detection device described in

[11] , since light incident on the second aperture at a large incident angle is difficult to pass through the opening, stray light can be suppressed from entering the light detector.

[0022] The light detection device according to one aspect of the present invention may be

[12] "a light detection device according to the above

[11] , wherein the outer edge of the second aperture is located on the inner side of the outer edge of the opening when viewed from the relative direction of the pair of mirror portions". According to the light detection device described in

[12] , since the incident angle of the light incident on the pair of mirror portions through the second aperture, the opening and the first aperture becomes smaller, the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured.

[0023] The optical detection device according to one aspect of the present invention may also be,

[13] "the optical detection device according to the above

[11] or

[12] , wherein the second aperture section includes a second enclosing portion enclosing the second aperture, and an engaging portion connected to the second enclosing portion and engaged with the package, the second aperture section in a direction perpendicular to the relative direction of the pair of mirror sections is positioned by the engaging portion and the package, and the second aperture section in the relative direction of the pair of mirror sections is positioned by the engaging portion and the package or by the second enclosing portion and the package". According to the optical detection device described in

[13] , when manufacturing the optical detection device, the center line of the second aperture can be aligned with the center line of the opening by passive alignment, and the distance between the opening and the second aperture can be set to a specified distance by passive alignment.

[0024] Effects of the Invention

[0025] According to the present invention, it is possible to provide a photodetection device and an aperture unit that can suppress the incidence of stray light on a photodetector. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional view of the photodetection device according to the first embodiment.

[0027] Figure 2 yes Figure 1 A stereogram of a Fabry-Perot interference filter is shown.

[0028] Figure 3 It is along Figure 2 A cross-sectional view of a Fabry-Perot interference filter along line III-III is shown.

[0029] Figure 4 yes Figure 1 A top view of the light detection device is shown.

[0030] Figure 5 It is a cross-sectional view of a photodetection device according to a second embodiment.

[0031] Figure 6 It is a cross-sectional view of a photodetection device according to a third embodiment.

[0032] Figure 7 It is a cross-sectional view of a photodetection device according to a fourth embodiment.

[0033] Figure 8 It is a cross-sectional view of a photodetection device according to a fifth embodiment.

[0034] Fig. 9 yes Figure 8 A top view of the light detection device is shown.

[0035] Fig.10 It is a cross-sectional view of a photodetection device according to a sixth embodiment.

[0036] Fig.11 It is a cross-sectional view of a photodetection device according to a seventh embodiment.

[0037] Fig.12 It is a diagram for explaining the effect of the first aperture unit.

[0038] Fig.13 It is a diagram for explaining the effect of the first aperture unit.

[0039] Fig.14 It is a diagram for explaining the effect of the first aperture unit.

[0040] Fig.15 It is a diagram for explaining the effect of the first aperture unit.

[0041] Fig.16 It is a diagram for explaining the effects of the first aperture unit and the second aperture unit.

[0042] Fig.17 It is a diagram for explaining the effects of the first aperture unit and the second aperture unit.

[0043] Fig.18 It is a diagram for explaining the effects of the first aperture unit and the second aperture unit.

[0044] Fig.19 It is a graph showing the results of spectroscopic analysis of the photodetection devices of the comparative example and Examples 1 to 4.

[0045] Fig. 20 It is a graph showing the results of spectroscopic analysis of the photodetection devices of the comparative example and Examples 1 to 4. DETAILED DESCRIPTION

[0046] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in each figure, the same or corresponding parts are marked with the same reference numerals, and repeated descriptions are omitted.

[0047] [First embodiment]

[0048] [Structure of the light detection device]

[0049] like Figure 1 As shown, the light detection device 1A of the first embodiment includes a package 2. The package 2 is a CAN package having a base 3 and a cover 4. The cover 4 includes a side wall 5 and a top wall 6. The side wall 5 and the top wall 6 are integrally formed of a metal material. The top wall 6 is integrally formed with the side wall 5 in a manner covering one opening of the cylindrical side wall 5. The base 3 is formed of a metal material. The base 3 is airtightly joined to the side wall 5 in a manner covering the other opening of the cylindrical side wall 5.

[0050] A wiring substrate 7 is fixed to the inner surface 3a of the base 3. The substrate material of the wiring substrate 7 is, for example, silicon, ceramic, quartz, glass, plastic, etc. A light detector 8 and temperature compensation elements such as thermistors (not shown) are mounted on the wiring substrate 7. The light detector 8 is, for example, an infrared detector. As an infrared detector, for example, a quantum sensor using InGaAs or the like, a thermal sensor using a thermopile or a bolometer, etc., etc. can be used. In the case of detecting light in each wavelength region of ultraviolet, visible, and near-infrared, as the light detector 8, for example, a silicon photodiode or the like can be used. In addition, the light receiving area of ​​the light detector 8 can be composed of a light detection element having a light receiving portion, or can also be composed of a light detection element having a plurality of light receiving portions arranged in an array. In addition, the light receiving area of ​​the light detector 8 can also be composed of a plurality of light detection elements.

[0051] A plurality of spacers 9 are fixed to the wiring substrate 7. The material of each spacer 9 is, for example, silicon, ceramic, quartz, glass, plastic, etc. A Fabry-Perot interference filter 10 is fixed to the plurality of spacers 9. That is, the Fabry-Perot interference filter 10 is supported by the plurality of spacers 9. The light transmission area 10a of the Fabry-Perot interference filter 10 is opposite to the light receiving part of the photodetector 8. In addition, the spacer 9 may also be formed integrally with the wiring substrate 7. In addition, the Fabry-Perot interference filter 10 may also be supported by one spacer 9.

[0052] A plurality of lead pins 11 are fixed to the base 3. Each lead pin 11 passes through the base 3 while ensuring electrical insulation and airtightness with the base 3 by an insulating member 17. Each lead pin 11 is electrically connected to an electrode pad provided on the wiring substrate 7, a terminal of the photodetector 8, a terminal of a temperature compensation element, and a terminal of a Fabry-Perot interference filter 10 via a wire 12. In the photodetection device 1A, input and output of electrical signals are respectively performed to the photodetector 8, the temperature compensation element, and the Fabry-Perot interference filter 10 via a plurality of lead pins 11.

[0053] The package 2 has an opening 20. The opening 20 is formed on the top wall 6 of the cover 4 in a manner opposite to the light transmission area 10a of the Fabry-Perot interference filter 10. A light transmission component 13 is airtightly joined to the inner surface 6a of the top wall 6. The light transmission component 13 blocks the opening 20. The light transmission component 13 has a light incident surface 13a and a light exit surface 13b that are opposite to each other, and a side surface 13c. The light incident surface 13a of the light transmission component 13 is substantially flush with the outer surface 6b of the top wall 6 at the opening 20. The side surface 13c of the light transmission component 13 is in contact with the inner surface 5a of the side wall 5 of the cover 4. Such a light transmission component 13 is formed by arranging glass particles on the inner side of the cover 4 with the opening 20 as the lower side and melting the glass particles.

[0054] The bandpass filter 14 is fixed to the light emitting surface 13b of the light transmitting member 13 by means of a light transmitting adhesive member 15. The bandpass filter 14 has a light incident surface 14a and a light emitting surface 14b facing each other, and a side surface 14c. The side surface 14c of the bandpass filter 14 is separated from the inner surface 5a of the side wall 5 of the cover 4. As an example, the bandpass filter 14 includes a light transmitting member formed in a rectangular plate shape by a light transmitting material (such as silicon, glass, etc.), and a dielectric multilayer film (such as TiO2) formed on the surface of the light transmitting member on the opposite side of the opening 20. 2 、 2 O 5 High refractive materials and SiO 2 MgF 2 In addition, the dielectric multilayer film may be formed on the surface of the light transmitting member on the side of the opening 20.

[0055] In the first embodiment, the light transmitting portion 16 is constituted by the light transmitting member 13, the adhesive member 15, and the band pass filter 14. That is, the light transmitting portion 16 includes the light transmitting member 13 that blocks the opening 20 and the band pass filter 14 that is arranged on the side opposite to the opening 20 with respect to the light transmitting member 13. The light incident surface 16a of the light transmitting portion 16 is the light incident surface 13a of the light transmitting member 13, and the light exit surface 16b of the light transmitting portion 16 is the light exit surface 14b of the band pass filter 14. The light exit surface 16b of the light transmitting portion 16 is located inside the package 2.

[0056] The photodetection device 1A includes a first aperture unit 51A having a first aperture 50. The first aperture 50 is a light passage hole located between the light emission surface 16b of the light transmission unit 16 and the Fabry-Perot interference filter 10 in the package 2. The first aperture unit 51A will be described in detail later.

[0057] In the first embodiment, the opening 20 of the package 2, the first aperture 50 of the first aperture portion 51A, the light transmission area 10a of the Fabry-Perot interference filter 10, and the light receiving area of ​​the photodetector 8 are arranged in this order on a straight line L. When viewed from a direction parallel to the straight line L, the straight line L passes through the centers of the opening 20, the first aperture 50, the light transmission area 10a, and the light receiving area. That is, in the photodetection device 1A, the Fabry-Perot interference filter 10 is arranged on the side opposite to the opening 20 with respect to the light emitting surface 16b of the light transmission portion 16 in the package 2, and the photodetector 8 is arranged on the side opposite to the opening 20 with respect to the Fabry-Perot interference filter 10 in the package 2.

[0058] In the light detection device 1A configured as described above, when the light of the measurement object enters the light transmission area 10a of the Fabry-Perot interference filter 10 via the opening 20, the light transmission portion 16 (i.e., the light transmission member 13, the adhesive member 15, and the bandpass filter 14), and the first aperture 50, the light of a predetermined wavelength in the light of the measurement object passes through the pair of mirrors of the Fabry-Perot interference filter 10. The light that has passed through the pair of mirrors of the Fabry-Perot interference filter 10 enters the photodetector 8 and is detected by the photodetector 8. As an example, in order to obtain the spectroscopic spectrum of the light of the measurement object, in the light detection device 1A, the voltage applied to the Fabry-Perot interference filter 10 is changed (i.e., the distance between the pair of mirrors in the Fabry-Perot interference filter 10 is changed), and the light that has passed through the light transmission area 10a of the Fabry-Perot interference filter 10 is detected by the photodetector 8.

[0059] [Structure of Fabry-Perot interference filter]

[0060] like Figure 2 As shown, the Fabry-Perot interference filter 10 has a light transmission region 10a. As an example, the Fabry-Perot interference filter 10 is in a rectangular plate shape, and the light transmission region 10a is in a cylindrical shape. Figure 3 As shown, the Fabry-Perot interference filter 10 includes a first mirror portion 35 and a second mirror portion 36 as a pair of mirror portions. The first mirror portion 35 and the second mirror portion 36 are arranged at a variable distance from each other in the light transmission region 10a. The first mirror portion 35 and the second mirror portion 36 are opposite to each other in a direction parallel to the straight line L. Hereinafter, the relative direction of the first mirror portion 35 and the second mirror portion 36 is referred to as direction A.

[0061] The Fabry-Perot interference filter 10 includes a substrate 21. On the surface 21a of the light incident side of the substrate 21, an antireflection layer 31, a first stack 32, an intermediate layer 33 and a second stack 34 are stacked in this order. Between the first stack 32 and the second stack 34, a gap (air gap) S is formed by the frame-shaped intermediate layer 33. The material of the substrate 21 is, for example, silicon, quartz, glass, etc. In the case where the material of the substrate 21 is silicon, the material of the antireflection layer 31 and the intermediate layer 33 is, for example, silicon oxide, etc. The thickness of the intermediate layer 33 is, for example, an integer multiple of 1 / 2 of the design center wavelength. In addition, as required, the thickness of the intermediate layer 33 may also be greater than an integer multiple of 1 / 2 of the design center wavelength.

[0062] The portion of the first stack 32 corresponding to the light transmission region 10a functions as the first mirror portion 35. The first mirror portion 35 is supported on the substrate 21 via the anti-reflection layer 31. As an example, the first stack 32 is formed by alternately stacking a plurality of polysilicon layers and a plurality of silicon nitride layers. The optical thickness of each layer constituting the first mirror portion 35 is, for example, an integral multiple of 1 / 4 of the design center wavelength. In addition, a silicon oxide layer may be used instead of a silicon nitride layer.

[0063] The portion of the second stack 34 corresponding to the light transmission region 10a functions as a second mirror portion 36 opposite to the first mirror portion 35 across a gap S. The second mirror portion 36 is supported on the substrate 21 via the anti-reflection layer 31, the first stack 32, and the intermediate layer 33. As an example, the second stack 34 is formed by alternately stacking a plurality of polysilicon layers and a plurality of silicon nitride layers one layer each. The optical thickness of each layer constituting the second mirror portion 36 is, for example, an integral multiple of 1 / 4 of the design center wavelength. In addition, a silicon oxide layer may be used instead of a silicon nitride layer.

[0064] In the portion corresponding to the gap S in the second stacked body 34, a plurality of through holes 34b are formed from the surface 34a on the opposite side of the gap S in the second stacked body 34 to the gap S. The plurality of through holes 34b are formed to such an extent that the function of the second mirror portion 36 is not substantially affected. The plurality of through holes 34b are used when the gap S is formed by removing a portion of the intermediate layer 33 by etching.

[0065] The first mirror portion 35 is provided with a first electrode 22 so as to surround the light transmission region 10a. The first mirror portion 35 is provided with a second electrode 23 so as to include the light transmission region 10a. The first electrode 22 and the second electrode 23 are formed by doping a portion of the polysilicon layer with impurities to reduce the resistance of the portion. The size of the second electrode 23 is substantially the same as that of the light transmission region 10a.

[0066] The third electrode 24 is formed on the second mirror portion 36. The third electrode 24 faces the first electrode 22 and the second electrode 23 via the gap S in the direction A. The third electrode 24 is formed by doping a portion of a polysilicon layer with impurities to reduce the resistance of the portion.

[0067] In the Fabry-Perot interference filter 10, the second electrode 23 is located on the same plane as the first electrode 22 in a direction perpendicular to the direction A. The distance between the second electrode 23 and the third electrode 24 is substantially the same as the distance between the first electrode 22 and the third electrode 24. When viewed from the direction A, the second electrode 23 is surrounded by the first electrode 22.

[0068] In the Fabry-Perot interference filter 10, a pair of terminals 25 are provided across the light transmission region 10a. Each terminal 25 is disposed in a through hole extending from the surface 34a of the second stack 34 to the first stack 32. Each terminal 25 is electrically connected to the first electrode 22 via a wiring 22a.

[0069] In the Fabry-Perot interference filter 10, a pair of terminals 26 are provided across the light transmission region 10a. Each terminal 26 is arranged in a through hole extending from the surface 34a of the second stack 34 to the intermediate layer 33. Each terminal 26 is electrically connected to the second electrode 23 via the wiring 23a, and is electrically connected to the third electrode 24 via the wiring 24a. In addition, the direction in which the pair of terminals 26 are arranged across the light transmission region 10a is perpendicular to the direction in which the pair of terminals 25 are arranged across the light transmission region 10a (see Figure 2 ).

[0070] A pair of grooves 27 are formed in the first stack 32. Each groove 27 extends in a ring shape so as to surround a portion of the wiring 23a extending from each terminal 26 along the direction A. Each groove 27 electrically insulates the first electrode 22 and the wiring 23a. A groove 28 is formed in the first stack 32. The groove 28 extends in a ring shape along the inner edge of the first electrode 22. The groove 28 electrically insulates the first electrode 22 and the second electrode 23. The area within each groove 27, 28 may be filled with an insulating material or may be a gap.

[0071] A pair of grooves 29 are formed in the second stacked body 34. Each groove 29 extends in a ring shape so as to surround each terminal 25. Each groove 29 electrically insulates each terminal 25 from the third electrode 24. The region within each groove 29 may be filled with an insulating material or may be a void.

[0072] On the surface 21b on the light emitting side of the substrate 21, the antireflection layer 41, the third stack 42, the intermediate layer 43 and the fourth stack 44 are stacked in this order. The antireflection layer 41 and the intermediate layer 43 have the same structure as the antireflection layer 31 and the intermediate layer 33, respectively. The third stack 42 and the fourth stack 44 have a stacked structure symmetrical to the first stack 32 and the second stack 34 with respect to the substrate 21, respectively. The antireflection layer 41, the third stack 42, the intermediate layer 43 and the fourth stack 44 have a function of suppressing the warping of the substrate 21.

[0073] In the third stack 42, the intermediate layer 43 and the fourth stack 44, an opening 40a is formed in a manner that includes the light transmission area 10a. When observed from the direction A, the size of the opening 40a is approximately the same as the size of the light transmission area 10a. The opening 40a is open on the light output side, and the bottom surface of the opening 40a reaches the anti-reflection layer 41. A light shielding layer 45 is formed on the surface of the light output side of the fourth stack 44. The material of the light shielding layer 45 is, 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 material of the protective layer 46 is, for example, aluminum oxide. In addition, by making the thickness of the protective layer 46 less than 100nm (preferably about 30nm), the optical influence caused by the protective layer 46 can be ignored.

[0074] In the Fabry-Perot interference filter 10 constructed as described above, when a voltage is applied to the first electrode 22 and the third electrode 24 via a plurality of terminals 25 and 26 to generate a potential difference between the first electrode 22 and the third electrode 24, an electrostatic force corresponding to the potential difference is generated between the first electrode 22 and the third electrode 24. By generating an electrostatic force between the first electrode 22 and the third electrode 24, the second mirror portion 36 is pulled toward the first mirror portion 35, and the distance between the first mirror portion 35 and the second mirror portion 36 is adjusted. At this time, the second electrode 23 having the same potential as the third electrode 24 functions as a compensation electrode, and the second mirror portion 36 is kept flat in the light transmission area 10a. In this way, in the Fabry-Perot interference filter 10, the distance between the first mirror portion 35 and the second mirror portion 36 is variable. Here, the wavelength of light passing through the Fabry-Perot interference filter 10 depends on the distance between the first mirror portion 35 and the second mirror portion 36. Therefore, by adjusting the voltage applied to the first electrode 22 and the third electrode 24 (the potential difference generated between the first electrode 22 and the third electrode 24 ), the wavelength of light transmitted through the Fabry-Perot interference filter 10 can be selected.

[0075] [Structure of the first aperture section]

[0076] like Figure 1 and Figure 4As shown, the first aperture portion 51A is composed of a plate-shaped first surrounding portion 52. When observed from direction A, the first surrounding portion 52 continuously surrounds the first aperture 50. When observed from direction A, the outer edge 50a of the first aperture 50 is located on the inner side of the outer edge 20a of the opening 20 of the package 2. The first surrounding portion 52 is arranged between the light transmission portion 16 and the Fabry-Perot interference filter 10 in the package 2. The first surrounding portion 52 has a pair of surfaces 52a, 52b, and a side surface 52c that are opposite to each other. Surface 52a is a surface on the side of the light transmission portion 16, and is in contact with the light exit surface 16b of the light transmission portion 16 (that is, the light exit surface 14b of the bandpass filter 14). Surface 52b is a surface on the side of the Fabry-Perot interference filter 10, and is separated from the Fabry-Perot interference filter 10.

[0077] At least the surface 52b on the Fabry-Perot interference filter 10 side of the outer surface of the first enclosing portion 52 has light absorption. As an example, by subjecting the outer surface of the first enclosing portion 52 formed into a plate shape by chrome plating, black alumite treatment, electroless nickel plating, coating with black paint, etc. (roughening treatment may also be performed at the same time) to the outer surface of the first enclosing portion 52, light absorption relative to light in the wavelength region from visible to near infrared is given. Not only the surface 52b, but also the surface 52a may have light absorption. In addition, on the surface having light absorption, the reflectivity of the incident light is suppressed to, for example, less than 20%. The reflectivity is preferably less than 10%, and more preferably less than 5%. In the case where the reflectivity has wavelength dependence or incident angle dependence, in the use band of the Fabry-Perot interference filter 10, the reflectivity can be as long as it converges within the numerical value as a general trend. For example, the reflectance may be measured at representative incident angles (eg, 5°, 30°, 45°, and 60°), and the average value thereof may be included in the above numerical value.

[0078] The first aperture section 51A is positioned in a direction perpendicular to the direction A by the first surrounding portion 52 and the package 2. Specifically, the first aperture section 51A is positioned in a direction perpendicular to the direction A by fitting the side surface 52c of the first surrounding portion 52 and the inner surface 5a of the side wall 5 of the cover 4. The first aperture section 51A is positioned in the direction A by the first surrounding portion 52 and the light transmission portion 16. Specifically, the first aperture section 51A is positioned in the direction A by contacting the surface 52a of the first surrounding portion 52 and the light emission surface 16b of the light transmission portion 16.

[0079] In a state where the first aperture portion 51A is positioned, the first surrounding portion 52 is fixed to at least one of the package 2 and the light transmitting portion 16. Specifically, the first surrounding portion 52 is fixed to at least one of the package 2 and the light transmitting portion 16 by at least one of an adhesive member (not shown) disposed between the side surface 14c of the band pass filter 14 and the inner surface 5a of the side wall 5, an adhesive member (not shown) disposed at a corner formed by the surface 52b of the first surrounding portion 52 and the inner surface of the side wall 5, and an adhesive member (not shown) disposed between the light emitting surface 14b of the band pass filter 14 and the surface 52a of the first surrounding portion 52.

[0080] [Function and Effect]

[0081] In the light detection device 1A, the first aperture 50 is located between the light exit surface 16b of the light transmission portion 16 and the Fabry-Perot interference filter 10. As a result, light incident on the opening 20 at a large incident angle is difficult to travel to the space on the side of the Fabry-Perot interference filter 10. Furthermore, in the light detection device 1A, the surface 52b on the side of the Fabry-Perot interference filter 10 in the first surrounding portion 52 surrounding the first aperture 50 is separated from the Fabry-Perot interference filter 10 and has light absorption. As a result, the light reflected on the inner surface of the package 2 by the first aperture 50 is incident on the surface 52b of the first surrounding portion 52 and is easily attenuated on the surface 52b of the first surrounding portion 52. Therefore, it is possible to suppress the incidence of stray light on the light detector 8. In addition, when the surface 52a on the side of the opening 20 in the first surrounding portion 52 has light absorption, light incident on the opening 20 at a large incident angle is repeatedly reflected and attenuated between the surface 52a and the inner surface 6a of the top wall 6, resulting in the light being suppressed from traveling from the first aperture 50 to the space on the side of the Fabry-Perot interference filter 10.

[0082] In the light detection device 1A, the outer edge 50a of the first aperture 50 is located inside the outer edge 20a of the opening 20 when viewed from the direction A. As a result, the incident angle of the light incident on the first mirror 35 and the second mirror 36 through the opening 20 and the first aperture 50 becomes smaller, so that the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured.

[0083] In the photodetection device 1A, the light transmission section 16 includes the light transmission member 13 that blocks the opening 20 and the bandpass filter 14 that is disposed on the opposite side of the opening 20 with respect to the light transmission member 13. Thus, light in a predetermined wavelength range can be incident on the first mirror 35 and the second mirror 36, so that the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured.

[0084] In the photodetection device 1A, the first aperture unit 51A is a plate-shaped first surrounding portion 52 fixed to at least one of the package 2 and the light transmitting portion 16. Thus, the first aperture unit 51A can be simplified in structure and the first aperture 50 can be located at a predetermined position.

[0085] In the photodetection device 1A, the first aperture 51A is positioned in a direction perpendicular to the direction A by the first surrounding portion 52 and the package 2. Thus, when manufacturing the photodetection device 1A, the center line of the first aperture 50 can be aligned with the center line of the opening 20 by passive alignment.

[0086] In the photodetection device 1A, the first aperture 51A is positioned in the direction A by the first surrounding portion 52 and the light transmitting portion 16. Thus, when manufacturing the photodetection device 1A, the distance between the opening 20 and the first aperture 50 can be set to a predetermined distance by passive alignment.

[0087] [Second embodiment]

[0088] like Figure 5 As shown, the light detection device 1B of the second embodiment is different from the light detection device 1A of the first embodiment in that a first aperture unit 51B is composed of a film-like first surrounding portion 52 .

[0089] The first surrounding portion 52 of the first aperture portion 51B is a light absorbing film formed on the light emitting surface 16b of the light transmitting portion 16 (i.e., the light emitting surface 14b of the bandpass filter 14), and continuously surrounds the first aperture 50 when viewed from the direction A. The surface 52b of the first surrounding portion 52 is separated from the Fabry-Perot interference filter 10 and has light absorption. The side surface 14c of the bandpass filter 14 and the side surface 52c of the first surrounding portion 52 reach the inner surface 5a of the side wall 5 of the cover 4.

[0090] According to the photodetection device 1B, similarly to the photodetection device 1A, it is possible to suppress the incidence of stray light on the photodetector 8 .

[0091] In the photodetection device 1B, the first aperture unit 51B is a film-shaped first surrounding portion 52 formed on the light emitting surface 16b of the light transmitting portion 16. Thus, the first aperture unit 50 can be located at a predetermined position while simplifying the structure of the first aperture unit 51B.

[0092] [Third Embodiment]

[0093] like Figure 6 As shown, the light detection device 1C of the third embodiment is different from the light detection device 1A of the first embodiment in that a first aperture unit 51C is composed of a first surrounding portion 52 and a supporting portion 53 .

[0094] The first surrounding portion 52 of the first aperture portion 51C is located between the light transmitting portion 16 and the Fabry-Perot interference filter 10 in the package 2, and continuously surrounds the first aperture 50 when viewed from the direction A. The support portion 53 supports the first surrounding portion 52 in the package 2 in a state where the surface 52a is separated from the light transmitting portion 16 and the surface 52b is separated from the Fabry-Perot interference filter 10. The support portion 53 is cylindrical, and when viewed from the direction A, it is erected on the inner surface 3a of the base 3 in a state of surrounding the wiring substrate 7, the photodetector 8, the plurality of spacers 9, the Fabry-Perot interference filter 10, the plurality of lead pins 11, and the plurality of wires 12. The first surrounding portion 52 is formed integrally with the support portion 53 in a manner covering the opening on the light transmitting portion 16 side of the cylindrical support portion 53. The surface 52b of the first surrounding portion 52 is separated from the Fabry-Perot interference filter 10 and has light absorption. In addition, the support portion 53 may also be composed of a plurality of pillars extending along the direction A.

[0095] According to the photodetection device 1C, similarly to the photodetection device 1A, it is possible to suppress the incidence of stray light on the photodetector 8 .

[0096] In the photodetection device 1C, the first aperture unit 51C includes a first surrounding portion 52 and a support portion 53 that supports the first surrounding portion 52 in the package 2. Thus, the first aperture 50 can be located at a predetermined position regardless of the shape of the package 2.

[0097] [Fourth Embodiment]

[0098] like Figure 7 As shown, the light detection device 1D according to the fourth embodiment is different from the light detection device 1A according to the first embodiment in that a light absorbing film 18 is formed on the inner surface of the package 2 .

[0099] The light absorbing film 18 is formed on the inner surface of the cover 4 (i.e., the inner surface 5a of the side wall 5 and the inner surface 6a of the top wall 6). In addition, the light absorbing film 18 may not be formed on the inner surface 6a of the top wall 6. In addition, the light absorbing film 18 may be formed on the inner surface 3a of the base 3.

[0100] According to the photodetection device 1D, similarly to the photodetection device 1A, it is possible to suppress the incidence of stray light on the photodetector 8 .

[0101] In the photodetecting device 1D, the light absorbing film 18 is formed on the inner surface of the package 2 . Thus, stray light can be attenuated not only on the surface 52 b of the first surrounding portion 52 but also on the inner surface of the package 2 .

[0102] [Fifth Embodiment]

[0103] like Figure 8 and Fig. 9As shown, the light detection device 1E of the fifth embodiment is different from the light detection device 1A of the first embodiment in that it includes a second aperture portion 61A having a second aperture 60. The second aperture 60 is a light passing hole located on the side opposite to the light emitting surface 16b of the light transmitting portion 16 relative to the opening 20 outside the package 2. When viewed from the direction A, the straight line L passes through the center of the second aperture 60.

[0104] The second aperture portion 61A is composed of a second surrounding portion 62 and a fitting portion 63. When viewed from the direction A, the second surrounding portion 62 continuously surrounds the second aperture 60. When viewed from the direction A, the outer edge 60a of the second aperture 60 is located on the inner side of the outer edge 20a of the opening 20 of the package 2. The fitting portion 63 is connected to the second surrounding portion 62 and is fitted with the package 2. In the fifth embodiment, the fitting portion 63 is cylindrical and fits with the side wall 5 of the cover 4. The second surrounding portion 62 is formed integrally with the fitting portion 63 in a manner that covers the opening of the cylindrical fitting portion 63 on the opposite side of the base 3.

[0105] The second aperture section 61A is positioned in a direction perpendicular to the direction A by the fitting portion 63 and the package 2. Specifically, the second aperture section 61A is positioned in a direction perpendicular to the direction A by fitting the inner surface 63a of the fitting portion 63 and the outer surface 5b of the side wall 5 of the cover 4. The second aperture section 61A is positioned in the direction A by the fitting portion 63 and the package 2. Specifically, the second aperture section 61A is positioned in the direction A by contacting the end surface 63b of the fitting portion 63 and the surface 5d of the flange portion 5c of the side wall 5. The end surface 63b is an end surface of the cylindrical fitting portion 63 on the opposite side to the second surrounding portion 62. The flange portion 5c is an outward flange portion provided at the end of the cylindrical side wall 5 on the opposite side to the top wall 6. In a state where the second aperture section 61A is positioned, the fitting portion 63 is fixed to the package 2. In addition, the fitting portion 63 may also be composed of a plurality of columnar portions extending in the direction A.

[0106] According to the photodetection device 1E, similarly to the photodetection device 1A, it is possible to suppress the incidence of stray light on the photodetector 8 .

[0107] In the photodetection device 1E, the second aperture section 61A includes the second aperture 60 located on the side opposite to the light emitting surface 16b of the light transmitting portion 16 relative to the opening 20 outside the package 2. Thus, light incident on the second aperture 60 at a large incident angle is less likely to pass through the opening 20, and therefore, it is possible to suppress stray light from being incident on the photodetector 8.

[0108] In the light detection device 1E, the outer edge 60a of the second aperture 60 is located inside the outer edge 20a of the opening 20 when viewed from the direction A. As a result, the incident angle of the light that passes through the second aperture 60, the opening 20, and the first aperture 50 and enters the first mirror 35 and the second mirror 36 becomes smaller, so that the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured.

[0109] In the light detection device 1E, the second aperture portion 61A is positioned in a direction perpendicular to the direction A by the fitting portion 63 and the package 2, and the second aperture portion 61A is positioned in the direction A by the fitting portion 63 and the package 2. Thus, when manufacturing the light detection device 1A, the center line of the second aperture 60 can be made consistent with the center line of the opening 20 by passive alignment, and the distance between the opening 20 and the second aperture 60 can be made a predetermined distance by passive alignment.

[0110] [Sixth Embodiment]

[0111] like Fig.10 As shown, the photodetection device 1F of the sixth embodiment is different from the photodetection device 1E of the fifth embodiment in that the second aperture section 61B is positioned in the direction A by the second surrounding portion 62 and the package 2 .

[0112] The second aperture portion 61B is positioned in a direction perpendicular to the direction A by the fitting portion 63 and the package 2. Specifically, the second aperture portion 61B is positioned in a direction perpendicular to the direction A by fitting the inner surface 63a of the fitting portion 63 and the outer surface 5b of the side wall 5 of the cover 4. The second aperture portion 61B is positioned in the direction A by the second surrounding portion 62 and the package 2. Specifically, the second aperture portion 61B is positioned in the direction A by contacting the surface 62a of the second surrounding portion 62 with the outer surface 6b of the top wall 6 of the cover 4. The surface 62a is a surface on the light transmission portion 16 side of the second surrounding portion 62. In a state where the second aperture portion 61B is positioned, at least one of the second surrounding portion 62 and the fitting portion 63 is fixed to the package 2. In addition, the fitting portion 63 may also be composed of a plurality of columnar portions extending in the direction A.

[0113] According to the photodetection device 1F, similarly to the photodetection device 1A, it is possible to suppress the incidence of stray light on the photodetector 8 .

[0114] In the photodetection device 1F, the second aperture section 61A includes the second aperture 60 located on the side opposite to the light emitting surface 16b of the light transmitting portion 16 relative to the opening 20 outside the package 2. Thus, light incident on the second aperture 60 at a large incident angle is less likely to pass through the opening 20, and therefore, it is possible to suppress stray light from being incident on the photodetector 8.

[0115] In the light detection device 1F, the outer edge 60a of the second aperture 60 is located inside the outer edge 20a of the opening 20 when viewed from the direction A. As a result, the incident angle of the light incident on the first mirror 35 and the second mirror 36 through the second aperture 60, the opening 20, and the first aperture 50 becomes smaller, so that the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured.

[0116] In the light detection device 1F, the second aperture portion 61B is positioned in a direction perpendicular to the direction A by the fitting portion 63 and the package 2, and the second aperture portion 61B is positioned in the direction A by the second surrounding portion 62 and the package 2. Thus, when manufacturing the light detection device 1A, the center line of the second aperture 60 can be aligned with the center line of the opening 20 by passive alignment, and the distance between the opening 20 and the second aperture 60 can be set to a predetermined distance by passive alignment.

[0117] [Seventh Embodiment]

[0118] like Fig.11 As shown, the light detection device 1G according to the seventh embodiment is different from the light detection device 1A according to the first embodiment in that the light transmission section 16 is formed of a light transmission member 13 .

[0119] In the photodetection device 1G, the light transmission section 16 includes the light transmission member 13 that blocks the opening 20 of the package 2, and does not include the bandpass filter 14 (see Figure 1 In this case, the light incident surface 16a of the light transmitting portion 16 is the light incident surface 13a of the light transmitting member 13, and the light exit surface 16b of the light transmitting portion 16 is the light exit surface 13b of the light transmitting member 13. The surface 52a of the first surrounding portion 52 is in contact with the light exit surface 13b of the light transmitting member 13.

[0120] According to the photodetection device 1G, similarly to the photodetection device 1A, it is possible to suppress the incidence of stray light on the photodetector 8 .

[0121] In the photodetection device 1G, the light transmitting portion 16 is the light transmitting member 13 that blocks the opening 20. Thus, the structure of the light transmitting portion 16 can be simplified.

[0122] [Effect of the first aperture section]

[0123] Reference Fig.12 (a)~ Fig.15 (b) of FIG. 5A further illustrates the effect of the first aperture unit 51A. Fig.12 (a)~ Fig.15 In (b), the adhesive member 15 and the wire 12 are omitted from illustration.

[0124] like Fig.12As shown in (a), in the light detection device 100 without the first aperture portion 51A, the stray light N1 incident on the opening 20 at a large incident angle is reflected on the inner surface of the package 2, obliquely passes through the light transmission area 10a of the Fabry-Perot interference filter 10, and is incident on the light detector 8. In addition, in the light detection device 100, the stray light N2 incident on the opening 20 at an incident angle larger than the incident angle of the stray light N1 is reflected on the inner surface of the package 2, and is incident on the light detector 8 without passing through the light transmission area 10a of the Fabry-Perot interference filter 10. In contrast, Fig.12 As shown in (b), in the light detection device 1A including the first aperture portion 51A, although the diameter of the first aperture 50 is larger than the diameter of the opening 20, the stray light N1 is attenuated on the surface 52a of the first surrounding portion 52, and the stray light N2 is blocked from traveling to the space on the Fabry-Perot interference filter 10 side by the first surrounding portion 52. Therefore, in the light detection device 1A including the first aperture portion 51A, the incidence of stray light on the light detector 8 can be suppressed compared to the light detection device 100 not including the first aperture portion 51A.

[0125] like Fig.13 As shown in (a), in the optical detection device 1A in which the diameter of the first aperture 50 is larger than the diameter of the opening 20, the stray light N incident on the optical detector 8 after multiple reflections in the package 2 is attenuated once on the surface 52a of the first surrounding portion 52. Fig.13 As shown in (b), in the light detecting device 1A in which the diameter of the first aperture 50 is smaller than the diameter of the opening 20, the stray light N that is incident on the light detector 8 after being reflected multiple times in the package 2 is attenuated multiple times on the surface 52a of the first surrounding portion 52. Therefore, in the light detecting device 1A in which the diameter of the first aperture 50 is smaller than the diameter of the opening 20, the incidence of the stray light on the light detector 8 can be suppressed compared to the light detecting device 1A in which the diameter of the first aperture 50 is larger than the diameter of the opening 20.

[0126] like Fig.14 As shown in (a) of FIG. 1 , in the light detection device 1A in which the diameter of the first aperture 50 is larger than the diameter of the aperture 20, the stray light N that passes through the aperture 20 and the first aperture 50 and travels toward the space on the Fabry-Perot interference filter 10 side includes stray light with a large incident angle. Fig.14As shown in (b), in the optical detection device 1A in which the diameter of the first aperture 50 is smaller than the diameter of the opening 20, the stray light N that passes through the opening 20 and the first aperture 50 and travels to the space on the side of the Fabry-Perot interference filter 10 does not include stray light with a large incident angle. Therefore, in the optical detection device 1A in which the diameter of the first aperture 50 is smaller than the diameter of the opening 20, it is possible to suppress the incidence of stray light on the optical detector 8 compared to the optical detection device 1A in which the diameter of the first aperture 50 is larger than the diameter of the opening 20. In addition, Fig.14 The light M shown in (a) and (b) is the light to be measured.

[0127] like Fig.15 As shown in (a) of FIG. 1 , in the light detection device 1A in which the diameter of the first aperture 50 is larger than the diameter of the aperture 20, the incident angle of the light M to be measured that enters the light transmission area 10a of the Fabry-Perot interference filter 10 through the aperture 20 and the first aperture 50 becomes larger. Fig.15 As shown in (b), in the light detection device 1A in which the diameter of the first aperture 50 is smaller than the diameter of the opening 20, the incident angle of the light M to be measured that enters the light transmission area 10a of the Fabry-Perot interference filter 10 through the opening 20 and the first aperture 50 becomes smaller. Therefore, in the light detection device 1A in which the diameter of the first aperture 50 is smaller than the diameter of the opening 20, the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured, compared with the light detection device 1A in which the diameter of the first aperture 50 is larger than the diameter of the opening 20.

[0128] [Effects of the first aperture unit and the second aperture unit]

[0129] Reference Fig.16 (a)~ Fig.18 (b) of the present invention further describes the effects of the first aperture unit 51A and the second aperture unit 61A. Fig.16 (a)~ Fig.18 In (b), the adhesive member 15 and the wire 12 are omitted from illustration.

[0130] like Fig.16 As shown in (a), in the light detection device 1A where the distance between the second aperture 60 and the first aperture 50 is small, the stray light N that passes through the second aperture 60, the opening 20, and the first aperture 50 and travels to the space on the Fabry-Perot interference filter 10 side includes stray light with a large incident angle. Fig.16As shown in (b), in the light detection device 1A in which the distance between the second aperture 60 and the first aperture 50 is large, the stray light N that travels through the second aperture 60, the opening 20, and the first aperture 50 to the space on the side of the Fabry-Perot interference filter 10 does not include stray light with a large incident angle. Therefore, in the light detection device 1A in which the distance between the second aperture 60 and the first aperture 50 is large, the incidence of stray light on the photodetector 8 is suppressed compared to the light detection device 1A in which the distance between the second aperture 60 and the first aperture 50 is small. In addition, Fig.16 The light M shown in (a) and (b) is the light to be measured.

[0131] like Fig.17 As shown in (a), in the light detection device 1A where the distance between the second aperture 60 and the first aperture 50 is small, the incident angle of the light M to be measured that enters the light transmission area 10a of the Fabry-Perot interference filter 10 through the second aperture 60, the opening 20, and the first aperture 50 becomes larger. Fig.17 As shown in (b), in the light detection device 1A in which the distance between the second aperture 60 and the first aperture 50 is large, the incident angle of the light M to be measured that enters the light transmission area 10a of the Fabry-Perot interference filter 10 through the second aperture 60, the opening 20, and the first aperture 50 becomes small. Therefore, in the light detection device 1A in which the distance between the second aperture 60 and the first aperture 50 is large, the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured, compared with the light detection device 1A in which the distance between the second aperture 60 and the first aperture 50 is small.

[0132] like Fig.18 As shown in (a), in the light detection device 1A in which the diameter of the second aperture 60 is large, the incident angle of the light M to be measured that enters the light transmission area 10a of the Fabry-Perot interference filter 10 through the second aperture 60, the opening 20, and the first aperture 50 becomes larger. Fig.18 As shown in (b), in the light detection device 1A having a small diameter of the second aperture 60, the incident angle of the light M to be measured that enters the light transmission area 10a of the Fabry-Perot interference filter 10 through the second aperture 60, the opening 20, and the first aperture 50 becomes smaller. Therefore, in the light detection device 1A having a small diameter of the second aperture 60, the S / N ratio and the resolution can be improved in the wavelength analysis of the light to be measured, compared with the light detection device 1A having a large diameter of the second aperture 60.

[0133] [Results of Spectroscopic Analysis of Photodetection Devices of Comparative Example and Examples 1 to 4]

[0134] As a comparative photodetection device, a device in which the first aperture unit 51A is removed from the photodetection device 1A of the first embodiment is prepared. In the comparative photodetection device, the thickness of the top wall 6 of the cover 4 is 0.4 mm, and the diameter of the opening 20 is 1.5 mm.

[0135] As the light detection devices of Examples 1 and 3, light detection devices having the same structure as the light detection device 1A of the first embodiment described above were prepared. In the light detection device of Example 1, the thickness of the top wall 6 of the cover 4 was 0.4 mm, the diameter of the opening 20 was 1.5 mm, the thickness of the first surrounding portion 52 was 0.1 mm, the diameter of the first aperture 50 was 1.25 mm, and the distance between the opening 20 and the first aperture 50 was 1.1 mm. In the light detection device of Example 3, the thickness of the top wall 6 of the cover 4 was 0.4 mm, the diameter of the opening 20 was 1.5 mm, the thickness of the first surrounding portion 52 was 0.1 mm, the diameter of the first aperture 50 was 0.5 mm, and the distance between the opening 20 and the first aperture 50 was 1.1 mm.

[0136] As the light detection devices of Examples 2 and 4, light detection devices having the same structure as the light detection device 1E of the fifth embodiment described above were prepared. In the light detection device of Example 2, the thickness of the second surrounding portion 62 was 0.1 mm, the diameter of the second aperture 60 was 0.5 mm, the thickness of the top wall 6 of the cover 4 was 0.4 mm, the diameter of the opening 20 was 1.5 mm, the thickness of the first surrounding portion 52 was 0.1 mm, the diameter of the first aperture 50 was 1.25 mm, the distance between the second aperture 60 and the opening 20 was 0, and the distance between the opening 20 and the first aperture 50 was 1.1 mm. In the light detection device of Example 4, the thickness of the second surrounding portion 62 is 0.1 mm, the diameter of the second aperture 60 is 0.5 mm, the thickness of the top wall 6 of the cover 4 is 0.4 mm, the diameter of the opening 20 is 1.5 mm, the thickness of the first surrounding portion 52 is 0.1 mm, the diameter of the first aperture 50 is 0.5 mm, the distance between the second aperture 60 and the opening 20 is 0, and the distance between the opening 20 and the first aperture 50 is 1.1 mm.

[0137] Fig.19 This is a graph showing the relationship between the wavelength and the output ratio when bright line light is incident on the light detection device of the comparative example and embodiments 1 to 4. In this spectroscopic analysis, bright line light with a wavelength of 1650nm is incident on the light detection device of the comparative example and embodiments 1 to 4. Fig.19 In FIG. 1 , the wavelength of the horizontal axis corresponds to the distance between the first mirror portion 35 and the second mirror portion 36 in the Fabry-Perot interference filter 10. Fig.19 In the figure, the output ratio on the vertical axis is the output ratio when the peak output is set to 100%. Fig.19As shown, in the order of comparative example, embodiment 1, embodiment 2, embodiment 3, and embodiment 4, the downward portion of the output ratio relative to the peak output decreases. Therefore, it can be said that in the order of comparative example, embodiment 1, embodiment 2, embodiment 3, and embodiment 4, the effect of suppressing the incidence of stray light on the light detector 8 is improved.

[0138] Fig. 20 This is a graph showing the relationship between wavelength and absorbance when light reflected from the surface of an actual sample is incident on the light detection device of the comparative example and embodiments 1 to 4. In this spectroscopic analysis, a PET plate having a thickness of 1 mm is irradiated with light in the near-infrared wavelength region, and light reflected from the surface of the PET plate is incident on the light detection device of the comparative example and embodiments 1 to 4. Fig.19 As shown, in the order of Comparative Example, Example 1, Example 2, Example 3, and Example 4, the fluctuations in absorbance become significant. Therefore, it can be said that in the order of Comparative Example, Example 1, Example 2, Example 3, and Example 4, the S / N ratio and resolution are improved.

[0139] [Modifications]

[0140] The present invention is not limited to the above-mentioned embodiments. For example, the light absorbing film 18 may also be applied to any one of the light detecting devices 1A to 1C, 1E to 1G. In addition, the second aperture section 61A may also be applied to any one of the light detecting devices 1A to 1D, 1G. In addition, the second aperture section 61B may also be applied to any one of the light detecting devices 1A to 1D, 1G. In addition, the light transmitting section 16 formed by the light transmitting member 13 may also be applied to any one of the light detecting devices 1A to 1F.

[0141] The light transmissive portion 16 is not limited to being composed of the light transmissive member 13, the adhesive member 15 and the bandpass filter 14, or being composed of the light transmissive member 13. The light transmissive portion 16 only needs to block the opening 20 of the package 2 and have the light emitting surface 16b located inside the package 2.

[0142] The first surrounding portion 52 may also intermittently (eg, via slits) surround the first aperture 50 when viewed from direction A. In addition, when viewed from direction A, the outer edge 50a of the first aperture 50 may also be located outside the outer edge 20a of the opening 20 of the package 2 .

[0143] The second surrounding portion 62 may also intermittently (eg, via slits) surround the second aperture 60 when viewed from direction A. In addition, when viewed from direction A, the outer edge 60a of the second aperture 60 may also be located outside the outer edge 20a of the opening 20 of the package 2 .

[0144] In addition, according to "an aperture portion, which is used in a light detection device, the light detection device comprises: a package having an opening; a light transmitting portion that blocks the opening; a Fabry-Perot interference filter, which is arranged on one side relative to the opening and the light transmitting portion in the package, and includes a pair of mirror portions whose distances from each other are variable; and a light detector, which is arranged on the one side relative to the Fabry-Perot interference filter in the package, the aperture portion comprises: an enclosing portion, which encloses an aperture located on the other side relative to the opening outside the package; a fitting portion, which is connected to the enclosing portion and fits with the package, positioning in a direction perpendicular to the relative direction of the pair of mirror portions is performed by the fitting portion and the package, and positioning in the relative direction of the pair of mirror portions is performed by the fitting portion and the package or by the enclosing portion and the package", by installing it in the light detection device, it is possible to suppress stray light from being incident on the light detector in the light detection device.

[0145] Explanation of symbols

[0146] 1A, 1B, 1C, 1D, 1E, 1F, 1G…light detection device, 2…package, 8…light detector, 10…Fabry-Perot interference filter, 13…light transmission component, 14…bandpass filter, 16…light transmission portion, 16b…light emitting surface, 18…light absorbing film, 20…opening, 20a…outer edge, 35…first mirror portion, 36…second mirror portion, 50…first aperture, 50a…outer edge, 51A, 51B, 51C…first aperture portion, 52…first surrounding portion, 52b…surface, 53…support portion, 60…second aperture, 60a…outer edge, 61A, 61B…second aperture portion, 62…second surrounding portion, 63…fitting portion, A…direction (relative direction of a pair of mirror portions).

Claims

1. A light detection device, wherein: have: a package having an opening; a light-transmitting portion blocking the opening and having a light-emitting surface located within the package; A Fabry-Perot interference filter, which is arranged on a side opposite to the opening relative to the light emitting surface in the package and includes a pair of mirror portions whose mutual distance is variable; a photodetector disposed in the package on a side opposite to the opening with respect to the Fabry-Perot interference filter; and a first aperture portion having a first aperture located between the light exit surface and the Fabry-Perot interference filter in the package; The first aperture section includes a first surrounding portion surrounding the first aperture, A surface of the first surrounding portion on the Fabry-Perot interference filter side is separated from the Fabry-Perot interference filter and has light absorptivity.

2. The light detection device according to claim 1, wherein: When viewed from the opposing direction of the pair of mirror portions, the outer edge of the first aperture is located inside the outer edge of the opening.

3. The light detection device according to claim 1 or 2, wherein: The light transmitting portion includes a light transmitting member that blocks the opening, and a band pass filter that is disposed on a side of the light transmitting member that is opposite to the opening.

4. The light detection device according to claim 1 or 2, wherein: The light transmitting portion is a light transmitting member that blocks the opening.

5. The light detection device according to any one of claims 1 to 4, wherein: The first aperture section is the first plate-shaped surrounding portion fixed to at least one of the package and the light transmitting section.

6. The light detection device according to claim 5, wherein: The first aperture portion is positioned in a direction perpendicular to the opposing direction of the pair of mirror portions by the first surrounding portion and the package.

7. The light detection device according to claim 5 or 6, wherein: The first aperture portion is positioned in the opposing direction of the pair of mirror portions by the first surrounding portion and the light transmitting portion.

8. The light detection device according to any one of claims 1 to 4, wherein: The first aperture section is the first surrounding portion in a film shape formed on the light emitting surface.

9. The light detection device according to any one of claims 1 to 4, wherein: The first aperture portion further includes a supporting portion that supports the first surrounding portion within the package.

10. The light detection device according to any one of claims 1 to 9, wherein: The package further includes a light absorbing film formed on the inner surface of the package.

11. The light detection device according to any one of claims 1 to 10, wherein: The package further includes a second aperture unit having a second aperture located on the side opposite to the light emitting surface with respect to the opening outside the package.

12. The light detection device according to claim 11, wherein When viewed from the opposing direction of the pair of mirror portions, the outer edge of the second aperture is located inside the outer edge of the opening.

13. The light detection device according to claim 11 or 12, wherein: The second aperture section includes a second surrounding portion surrounding the second aperture and a fitting portion connected to the second surrounding portion and fitted with the package. The second aperture portion is positioned in a direction perpendicular to the relative direction of the pair of mirror portions by the fitting portion and the package. The positioning of the second aperture portion in the opposing direction of the pair of mirror portions is performed by the fitting portion and the package or by the second surrounding portion and the package.

14. An aperture unit, wherein: It is the aperture part used in the light detection device. The light detection device comprises: a package having an opening; a light transmitting portion that blocks the opening; a Fabry-Perot interference filter, which is arranged on one side relative to the opening and the light transmitting portion in the package and includes a pair of mirror portions whose mutual distance is variable; and a photodetector disposed on the one side relative to the Fabry-Perot interference filter in the package, The aperture unit comprises: a surrounding portion surrounding the aperture located on the other side of the opening outside the package; and a fitting portion connected to the surrounding portion and fitted with the packaging member, Positioning in a direction perpendicular to the relative direction of the pair of mirror portions is performed by the fitting portion and the packaging member. The pair of mirror portions are positioned in relative directions by the fitting portion and the package or by the surrounding portion and the package.

Images