Optical device

Abstract

In an optical device, a base and a movable portion are composed of a semiconductor substrate having a first semiconductor layer, an insulating layer, and a second semiconductor layer in this order from one side in a prescribed direction. The base is composed of the first semiconductor layer, the insulating layer, and the second semiconductor layer. The movable portion has a placement portion composed of the second semiconductor layer. An optical functional portion is placed on a surface on one side of the placement portion. The optical device further has an electrode pad provided to the base, the electrode pad being placed on a surface on one side of the second semiconductor layer in an opening formed in a surface on one side of the first semiconductor layer in such a manner as to reach the second semiconductor layer.

Description

[0001] This application was filed on [date]. July 6, 2018 Application number 201880041551.9, invention title: reflector unit A divisional application of the patent application. Technical Field

[0002] This invention relates to optical devices. Background Technology

[0003] Optical devices with interferometric optical systems formed on SOI (Silicon On Insulator) substrates using MEMS (Micro Electro Mechanical Systems) technology are known (see, for example, Patent Document 1). Such optical devices have attracted attention because they can provide FTIR (Fourier Transform Infrared Spectrometer) instruments with highly precise optical configurations.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2012-524295 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In the aforementioned optical devices, the movable mirror constituting the interference optical system moves along the principal surface of the SOI substrate. Conversely, to achieve a larger mirror surface, a structure is considered where the movable mirror moves in a direction perpendicular to the principal surface of the SOI substrate. However, simply employing such a structure does not adequately protect the mirror surface, leading to a decrease in the device's reliability.

[0009] One aspect of the present invention is to provide a highly reliable optical device.

[0010] Methods for solving problems

[0011] An optical device according to one aspect of the present invention includes: a substrate having a main surface; a movable portion supported on the substrate in a manner capable of moving along a predetermined direction intersecting the main surface; and an optical functional portion disposed on the movable portion. The substrate and the movable portion are composed of a semiconductor substrate having a first semiconductor layer, an insulating layer, and a second semiconductor layer sequentially from one side in the predetermined direction. The substrate is composed of the first semiconductor layer, the insulating layer, and the second semiconductor layer. The movable portion has a placement portion composed of the second semiconductor layer. The optical functional portion is disposed on a surface of one side of the placement portion. The first semiconductor layer constituting the substrate is thicker than the second semiconductor layer constituting the substrate. The surface of one side of the substrate is located on a side closer to the optical functional portion.

[0012] In this optical device, one side of the substrate is located further to the side than the optical functional part. Therefore, the substrate can protect the optical functional part, for example, preventing damage to the optical functional part due to direct contact during handling, etc. Furthermore, in this optical device, the first semiconductor layer constituting the substrate is thicker than the second semiconductor layer constituting the substrate. This ensures sufficient protrusion of the substrate relative to the optical functional part, effectively protecting the optical functional part. Therefore, the reliability of this optical device is improved.

[0013] Alternatively, the structure may include a beam portion disposed around the optical functional part. This beam portion is composed of a first semiconductor layer disposed on the second semiconductor layer and an insulating layer. One end face of the beam portion is located further to the side than the optical functional part. In this case, the beam portion can also protect the optical functional part. Furthermore, the beam portion can suppress deformation of the movable part during movement.

[0014] The beam can also be positioned on one side of the mounting section, extending along the outer edge of the mounting section when viewed from a specified direction. In this case, the beam can be positioned near the optical functional section, thus protecting the optical functional section more effectively. Furthermore, since the beam is positioned on the mounting section, deformation of the mounting section can be more appropriately suppressed.

[0015] The movable part may also have a frame portion that surrounds the configuration portion when viewed from a predetermined direction and a connecting portion that connects the configuration portion and the frame portion to each other. The frame portion and the connecting portion are made of a second semiconductor layer, and the beam portion is disposed on the surface of one side of the frame portion in such a way that it extends along the frame portion when viewed from a predetermined direction.

[0016] In this case, the beam can be used to more effectively protect the optical functional parts. Furthermore, the beam can be used to suppress the deformation of the frame, thereby suppressing the deformation of the configuration parts caused by the deformation of the frame.

[0017] The first semiconductor layer constituting the beam can also be thinner than the first semiconductor layer constituting the substrate. In this case, it is possible to suppress the protrusion of the beam from the substrate during the movement of the movable part, and to increase the amount of movement of the movable part in a predetermined direction.

[0018] An optical device according to one aspect of the present invention may also have the following structure: it further includes an electrode pad disposed on a substrate, the electrode pad being disposed within an opening formed on a surface of the first semiconductor layer to reach the second semiconductor layer, and the substrate having a groove formed on a surface of the first semiconductor layer to reach the second semiconductor layer and extending to surround the opening when viewed from a predetermined direction. In this case, the groove can be used to achieve electrical insulation of the electrode pad, further improving reliability.

[0019] The electrode pad can also extend across the bottom and sides of the opening. In this case, a large-area electrode pad can be achieved.

[0020] Alternatively, the structure can be as follows: the electrode pad and the optical functional part are each composed of a metal layer, with the metal layer constituting the electrode pad being thicker than the metal layer constituting the optical functional part. In this case, deformation of the optical functional part can be suppressed, and electrical connection to the electrode pad can be achieved.

[0021] One aspect of the present invention includes a reflector unit comprising: the aforementioned optical device; an optical functional component disposed on the other side of the optical device in a predetermined direction; and a fixed reflector disposed on the other side of the optical functional component. The optical functional component, together with a movable component, forms a reflector surface of a movable reflector. A first light-passing portion is formed in the optical device, constituting a first part of the optical path between the beam splitter unit and the fixed reflector. The beam splitter unit, together with the movable reflector and the fixed reflector, constitutes an interference optical system. A second light-passing portion is formed in the optical functional component, constituting a second part of the optical path between the beam splitter unit and the fixed reflector. The second light-passing portion corrects the optical path difference generated between the optical path between the beam splitter unit and the movable reflector and between the optical path between the beam splitter unit and the fixed reflector.

[0022] In this mirror unit, reliability can be improved for the reasons stated above. Furthermore, by improving the second light-transmitting portion of the optical functional component, the difference in optical path length between the beam splitter unit and the movable mirror, and between the beam splitter unit and the fixed mirror, can be corrected. Moreover, in this mirror unit, the mirror surface is positioned near the optical functional component. This structure is particularly effective in correcting the difference in optical path length using the second light-transmitting portion of the optical functional component.

[0023] The effects of the invention

[0024] According to one aspect of the present invention, it is possible to provide optical devices with high reliability. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of an optical component in one embodiment.

[0026] Figure 2 yes Figure 1 The top view of the reflector unit shown.

[0027] Figure 3 It is along Figure 2 The cross-sectional view of the reflector unit along line III-III is shown.

[0028] Figure 4 It is along Figure 2 The cross-sectional view of the reflector unit along line IV-IV is shown.

[0029] Figure 5 It is along Figure 2 A schematic cross-sectional view of the VV-line reflector device shown.

[0030] Figure 6 yes Figure 2 A partially enlarged view of the reflector device shown.

[0031] Figure 7 yes Figure 2 A top view of the optical functional components shown.

[0032] Figure 8 It is along Figure 1 The cross-sectional view of the optical component along line VIII-VIII is shown.

[0033] Figure 9 It is along Figure 1 The cross-sectional view of the optical component of the IX-IX line is shown.

[0034] Figure 10 yes Figure 1 A schematic cross-sectional view of the reflector unit and beam splitter unit shown.

[0035] Figure 11 It is along Figure 2 A schematic cross-sectional view of the reflector device along the XI-XI line. Detailed Implementation

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the same reference numerals are used to denote the same or equivalent parts in each drawing, and repeated parts are omitted.

[0037] [Structure of optical components]

[0038] like Figure 1As shown, the optical assembly 1 includes a mirror unit 2, a beam splitter unit 3, a light incident section 4, a first photodetector 6, a second light source 7, a second photodetector 8, a support body 9, a first support structure 11, and a second support structure 12. The mirror unit 2 is disposed on one side of the support body 9 in the Z-axis direction (a predetermined direction, the first direction), and is mounted to the support body 9, for example, by an adhesive. The support body 9 is formed, for example, of copper-tungsten alloy, and is, for example, in the shape of a rectangular plate. The mirror unit 2 includes a movable mirror 22 that moves along the Z-axis direction and a fixed mirror 16 whose position is fixed (details will be described later). In addition, the Z-axis direction is, for example, a vertical direction, and one side in the Z-axis direction is, for example, the upper side.

[0039] Beam splitter unit 3 is disposed on one side of mirror unit 2 in the Z-axis direction and is supported by first support structure 11. First support structure 11 is mounted to support body 9, for example, by adhesive. Light incident section 4 is disposed on one side of beam splitter unit 3 in the X-axis direction (a third direction perpendicular to the first direction) and is supported by second support structure 12. First photodetector 6, second light source 7, and second photodetector 8 are disposed on one side of beam splitter unit 3 in the Z-axis direction and are supported by second support structure 12. Second support structure 12 is mounted to support body 9, for example, by bolts.

[0040] In optical component 1, the beam splitter unit 3, the movable mirror 22, and the fixed mirror 16 constitute an interferometric optical system structure for the measurement light L0 and the laser L10, respectively. The interferometric optical systems constituting the measurement light L0 and the laser L10 are, for example, Michelson interferometric optical systems.

[0041] For the measurement light L0, the interference light L1 of the measurement light is detected as follows. That is, when the measurement light L0, which is incident from the first light source (not shown) through the measurement object (not shown) or emitted from the measurement object (e.g., the emission of light from the measurement object itself), is incident from the light incident section 4 onto the beam splitter unit 3, the measurement light L0 is split into a portion and a remainder in the beam splitter unit 3. Moreover, a portion of the measurement light L0 is reflected back to the beam splitter unit 3 by the movable reflector 22, which moves back and forth along the Z-axis. On the other hand, the remainder of the measurement light L0 is reflected back to the beam splitter unit 3 by the fixed reflector 16. The portion and the remainder of the measurement light L0 that return to the beam splitter unit 3 are emitted from the beam splitter unit 3 as the interference light L1, which is detected by the first photodetector 6.

[0042] For laser L10, the interference beam L11 is detected as follows: When laser L10 emitted from the second light source 7 is incident on beam splitter unit 3, it is split into a portion and a remainder. A portion of laser L10 is reflected back to beam splitter unit 3 by a movable mirror 22 that reciprocates along the Z-axis. The remainder of laser L10 is reflected back to beam splitter unit 3 by a fixed mirror 16. The portion and remainder of laser L10 returning to beam splitter unit 3 are emitted as interference beam L11, which is detected by the second photodetector 8.

[0043] Based on the optical component 1, the position of the movable reflector 22 in the Z-axis direction can be calculated based on the detection result of the interference light L11 of the laser, and the spectral analysis of the measured object can be performed based on the position calculation result and the detection result of the interference light L1 of the measurement light.

[0044] [Structure of the reflector unit]

[0045] like Figure 2 , Figure 3 and Figure 4 As shown, the mirror unit 2 includes a mirror device (optical device) 20, an optical functional component 13, a fixed mirror 16, and a stress-relieving substrate 17. The mirror device 20 includes a substrate 21, a movable mirror 22, and a drive unit 23.

[0046] The substrate 21 has a first surface 21a (a surface on one side in the Z-axis direction) and a second surface 21b opposite to the first surface 21a. The first surface 21a and the second surface 21b are the main surfaces of the substrate 21. The substrate 21 is, for example, in the shape of a rectangular plate, and has dimensions of approximately 10 mm × 15 mm × 0.35 mm (thickness). The movable mirror 22 has a reflecting mirror surface (optical functional part) 22a and a movable part 22b on which the reflecting mirror surface 22a is disposed. The movable mirror 22 (movable part 22b) is supported on the substrate 21 in such a way that it can move along the Z-axis direction (a predetermined direction perpendicular to the first surface 21a). The drive unit 23 moves the movable mirror 22 along the Z-axis direction.

[0047] A pair of light-passing openings 24 and 25 are provided on the reflector device 20. The pair of light-passing openings 24 and 25 are arranged on both sides of the movable reflector 22 in the X-axis direction. The light-passing opening (first light-passing portion) 24 constitutes the first part of the optical path between the beam splitter unit 3 and the fixed reflector 16. In addition, in this embodiment, the light-passing opening 25 does not function as a light-passing opening.

[0048] Here, refer to Figure 2 , Figure 5 and Figure 6 The structure of the reflector device 20 will be described in detail. Additionally, Figure 5 yes Figure 3 The schematic cross-sectional view of the reflector device 20 shown is in... Figure 5 In the diagram, for example, the reflector device 20 is schematically represented with its dimensions in the Z-axis direction magnified compared to the actual dimensions.

[0049] The substrate 21, the movable part 22b of the movable mirror 22, and the driving part 23 are all constructed from an SOI (Silicon On Insulator) substrate (semiconductor substrate) 100. That is, the mirror device 20 is constructed from the SOI substrate 100. The mirror device 20 is formed, for example, in the shape of a rectangular plate. The SOI substrate 100 has a support layer 101, a device layer 102, and an intermediate layer 103. The support layer 101 is a first silicon layer (first semiconductor layer). The device layer 102 is a second silicon layer (second semiconductor layer). The intermediate layer 103 is an insulating layer disposed between the support layer 101 and the device layer 102. The SOI substrate 100 has the support layer 101, the intermediate layer 103, and the device layer 102 sequentially from one side in the Z-axis direction.

[0050] The substrate 21 is composed of a support layer 101, a device layer 102, and a portion of an intermediate layer 103. A first surface 21a of the substrate 21 is the surface of the support layer 101 opposite to the intermediate layer 103. A second surface 21b of the substrate 21 is the surface of the device layer 102 opposite to the intermediate layer 103. The support layer 101 constituting the substrate 21 is thicker than the device layer 102 constituting the substrate 21. The thickness of the support layer 101 constituting the substrate 21 is, for example, about four times the thickness of the device layer 102 constituting the substrate 21. In the mirror unit 2, as described later, the second surface 21b of the substrate 21 is bonded to the third surface 13a of the optical functional component 13 (see reference). Figure 3 and Figure 4 ).

[0051] The movable reflector 22 is positioned with the intersection of axes R1 and R2 as its center (center of gravity). Axis R1 is a straight line extending in the X-axis direction. Axis R2 is a straight line extending in the Y-axis direction (a second direction perpendicular to the first and third directions). When viewed from the Z-axis direction, the portion of the reflector device 20 other than the portion overlapping the sixth surface 21d of the substrate 21 (described later) is linearly symmetrical about axes R1 and R2, respectively.

[0052] The movable reflector 22 (movable part 22b) has a mounting part 221, a frame part 222, a pair of connecting parts 223, and a beam part 224. The mounting part 221, the frame part 222, and the pair of connecting parts 223 are formed by a portion of the device layer 102. The mounting part 221 is circular when viewed from the Z-axis direction. The mounting part 221 has a central part 221a and an outer edge part 221b. A reflective mirror surface 22a is provided on the surface 221as on one side of the central part 221a in the Z-axis direction, for example by forming a metal film (metal layer). The reflective mirror surface 22a extends perpendicularly to the Z-axis direction and is circular. The surface 221as of the central part 221a is the surface on the side of the intermediate layer 103 of the device layer 102. The reflective mirror surface 22a is located on the side of the substrate 21 that is closer to the Z-axis than the first surface 21a. In other words, the first surface 21a is located on the side that is closer to the Z-axis than the reflective mirror surface 22a. The outer edge 221b surrounds the central part 221a when viewed from the Z-axis direction.

[0053] The frame portion 222 extends in a ring shape, surrounding the arrangement portion 221 with a predetermined gap when viewed from the Z-axis direction. For example, the frame portion 222 is annular when viewed from the Z-axis direction. A pair of connecting portions 223 connect the arrangement portion 221 and the frame portion 222 to each other. The pair of connecting portions 223 are arranged on both sides of the arrangement portion 221 in the Y-axis direction.

[0054] The beam portion 224 is composed of a support layer 101 and an intermediate layer 103 disposed on the device layer 102. The beam portion 224 is disposed around the periphery of the reflector surface 22a. The beam portion 224 has an inner beam portion 224a, an outer beam portion 224b, and a pair of connecting beam portions 224c. The inner beam portion 224a is disposed on the surface of the outer edge portion 221b in the Z-axis direction. The inner beam portion 224a surrounds the reflector surface 22a when viewed from the Z-axis direction. For example, the outer edge of the inner beam portion 224a extends along the outer edge of the placement portion 221, leaving a predetermined gap when viewed from the Z-axis direction. The inner edge of the inner beam portion 224a extends along the outer edge of the reflector surface 22a, leaving a predetermined gap when viewed from the Z-axis direction. The end face 224as of the inner beam portion 224a in the Z-axis direction is located on the side closer to the Z-axis direction than the reflecting mirror surface 22a.

[0055] The outer beam portion 224b is disposed on the surface of the frame portion 222 on one side in the Z-axis direction. When viewed from the Z-axis direction, the outer beam portion 224b surrounds the inner beam portion 224a, and consequently surrounds the reflector surface 22a. For example, when viewed from the Z-axis direction, the outer edge of the outer beam portion 224b extends along the outer edge of the frame portion 222, leaving a predetermined gap. When viewed from the Z-axis direction, the inner edge of the outer beam portion 224b extends along the inner edge of the frame portion 222, leaving a predetermined gap. The end face 224bs of the outer beam portion 224b on one side in the Z-axis direction is located on the side closer to the reflector surface 22a in the Z-axis direction.

[0056] A pair of connecting beams 224c are respectively disposed on one side of the surface of a pair of connecting parts 223 in the Z-axis direction. Each connecting beam 224c connects the inner beam 224a and the outer beam 224b to each other. The end face 224cs of one side of the connecting beam 224c in the Z-axis direction is located on the side closer to the Z-axis direction than the reflecting mirror surface 22a.

[0057] The thicknesses of the inner beam portion 224a, outer beam portion 224b, and each connecting beam portion 224c in the Z-axis direction are equal. That is, the thickness of the support layer 101 constituting the inner beam portion 224a, outer beam portion 224b, and each connecting beam portion 224c is equal. The end faces 224as of the inner beam portion 224a, 224bs of the outer beam portion 224b, and 224cs of each connecting beam portion 224c are located on the same plane perpendicular to the Z-axis direction. The support layer 101 constituting the inner beam portion 224a, outer beam portion 224b, and each connecting beam portion 224c is thinner than the support layer 101 constituting the substrate 21. As a result, the end faces 224as, 224bs, and 224cs are located on the side of the substrate 21 that is closer to the first surface 21a in the Z-axis direction. In other words, the first surface 21a is located on the opposite side of the end surfaces 224as, 224bs, and 224cs in the Z-axis direction.

[0058] Viewed from the Z-axis direction, the width of the outer beam portion 224b is wider than the width of the inner beam portion 224a. The width of the inner beam portion 224a, viewed from the Z-axis direction, is the length of the inner beam portion 224a in the direction perpendicular to its extension direction; in this embodiment, it is the length of the inner beam portion 224a in the radial direction. The same applies to the width of the outer beam portion 224b when viewed from the Z-axis direction. The width of each connecting beam portion 224c is greater than the width of both the inner beam portion 224a and the outer beam portion 224b. The width of each connecting beam portion 224c is the length of each connecting beam portion 224c along the extension direction of the inner beam portion 224a.

[0059] The drive unit 23 has a first elastic support 26, a second elastic support 27, and an actuator 28. The first elastic support 26, the second elastic support 27, and the actuator 28 are formed by a portion of the device layer 102.

[0060] The first elastic support portion 26 and the second elastic support portion 27 are respectively connected between the base 21 and the movable reflector 22. The first elastic support portion 26 and the second elastic support portion 27 support the movable reflector 22 in such a way that the movable reflector 22 (movable portion 22b) can move along the Z-axis direction.

[0061] The first elastic support portion 26 has a pair of levers 261, a first connecting member 262, a second connecting member 263, a pair of beam members 264, an intermediate member 265, a pair of first torsion bars (first torsion support portions) 266, a pair of second torsion bars (second torsion support portions) 267, a pair of nonlinear easing springs 268, and a plurality of electrode supports 269.

[0062] A pair of levers 261 are positioned on either side of the light-passing opening 24 along the Y-axis, facing each other in the Y-axis direction. Each lever 261 is plate-shaped, extending along a plane perpendicular to the Z-axis. Each lever 261 has a first portion 261a, a second portion 261b positioned opposite the first portion 261a on the opposite side of the movable reflector 22, and a third portion 261c connected to the first portion 261a and the second portion 261b. The first portion 261a and the second portion 261b extend along the X-axis direction. The length of the first portion 261a in the X-axis direction is shorter than the length of the second portion 261b in the X-axis direction. The third portion 261c of the pair of levers 261 extends obliquely, becoming increasingly separated from each other as they move further away from the movable reflector 22.

[0063] A first connecting member 262 is mounted between the first ends 261d of a pair of levers 261 on the opposite side of the movable reflector 22. The first connecting member 262 is plate-shaped, extending along a plane perpendicular to the Z-axis, and extends along the Y-axis. A second connecting member 263 is mounted between the second ends 261e of the pair of levers 261 on the movable reflector 22 side. The second connecting member 263 is plate-shaped, extending along a plane perpendicular to the Z-axis, and extends along the Y-axis. The width of the second connecting member 263 in the X-axis direction is narrower than the width of the first connecting member 262 in the X-axis direction. The length of the second connecting member 263 in the Y-axis direction is shorter than the length of the first connecting member 262 in the Y-axis direction.

[0064] A pair of beam members 264 are respectively mounted between the second portion 261b of a pair of levers 261 and the first connecting member 262. Each beam member 264 is plate-shaped and extends along a plane perpendicular to the Z-axis. The pair of beam members 264 extend obliquely, becoming closer to each other the farther away from the movable reflector 22. The pair of levers 261, the first connecting member 262, the second connecting member 263, and the pair of beam members 264 define a light-passing opening 24. The light-passing opening 24 is polygonal when viewed from the Z-axis direction. The light-passing opening 24 is, for example, a cavity (hole). Alternatively, a material that is translucent relative to the measuring light L0 and the laser L10 may be disposed within the light-passing opening 24.

[0065] The intermediate component 265 is a plate extending along a plane perpendicular to the Z-axis and along the Y-axis. The intermediate component 265 is disposed between the movable mirror 22 and the second connecting component 263 (in other words, between the movable mirror 22 and the light-passing opening 24). As described later, the intermediate component 265 is connected to the movable mirror 22 by a non-linear buffer spring 268.

[0066] A pair of first torsion bars 266 are respectively mounted between the first end 261d of one lever 261 and the base 21, and between the first end 261d of the other lever 261 and the base 21. That is, the pair of first torsion bars 266 are respectively connected between the pair of levers 261 and the base 21. Each first torsion bar 266 extends along the Y-axis direction. The pair of first torsion bars 266 are arranged on the same center line parallel to the Y-axis direction. In this embodiment, the center line of each first torsion bar 266 is on the same straight line as the center line of the first connecting member 262. A protrusion 261f protruding outward in the Y-axis direction is provided at the first end 261d of each lever 261, and each first torsion bar 266 is connected to the protrusion 261f.

[0067] A pair of second torsion bars 267 are respectively mounted between the second end 261e of one lever 261 and one end of the intermediate component 265, and between the second end 261e of the other lever 261 and the other end of the intermediate component 265. That is, the pair of second torsion bars 267 are respectively connected between the pair of levers 261 and the movable reflector 22. Each second torsion bar 267 extends along the Y-axis direction. The pair of second torsion bars 267 are arranged on the same center line parallel to the Y-axis direction.

[0068] A pair of nonlinear buffer springs 268 are connected between the movable reflector 22 and the intermediate member 265. Specifically, the pair of nonlinear buffer springs 268 are connected between the movable reflector 22 and the second torsion bar 267. Each nonlinear buffer spring 268 has a meandering portion 268a that extends meanderingly when viewed from the Z-axis direction. The meandering portion 268a extends in the Y-axis direction and includes a plurality of straight portions 268b arranged in the X-axis direction and a plurality of folded portions 268c that alternately connect the two ends of the multiple straight portions 268b. One end of the meandering portion 268a is connected to the intermediate member 265, and the other end of the meandering portion 268a is connected to the frame portion 222. The portion of the meandering portion 268a on the frame portion 222 side has a shape formed along the outer edge of the frame portion 222.

[0069] The nonlinear easing spring 268 is configured such that, after the movable reflector 22 has moved in the Z-axis direction, the deformation of the nonlinear easing spring 268 around the Y-axis is smaller than the deformation of the first torsion bar 266 and the second torsion bar 267 around the Y-axis, and the deformation of the nonlinear easing spring 268 in the X-axis direction is larger than the deformation of the first torsion bar 266 and the second torsion bar 267 in the X-axis direction. This suppresses nonlinearity in the torsional deformation of the first torsion bar 266 and the second torsion bar 267, and prevents a decrease in the control characteristics of the movable reflector 22 caused by this nonlinearity. Furthermore, the deformation of the first torsion bar 266, the second torsion bar 267, and the nonlinear easing spring 268 around the Y-axis refers, for example, to the absolute value of the torsion amount (torsion angle). The deformation of the first torsion bar 266, the second torsion bar 267, and the nonlinear easing spring 268 in the X-axis direction refers, for example, to the absolute value of the deflection. The deformation of a component in the Y-axis direction refers to the circumferential deformation of the component in the direction of a circle centered on an axis passing through the center of the component and parallel to the Y-axis. The same applies to the first torsion bar 276, the second torsion bar 277, and the nonlinear buffer spring 278, which will be described later.

[0070] Multiple electrode supports 269 include a pair of first electrode supports 269a, a pair of second electrode supports 269b, and a pair of third electrode supports 269c. Each electrode support 269a, 269b, and 269c is plate-shaped, extending along a plane perpendicular to the Z-axis direction and along the Y-axis direction. Each electrode support 269a, 269b, and 269c extends from the second portion 261b of the lever 261 towards the side opposite to the light-passing opening 24. The pair of first electrode supports 269a are arranged on the same center line parallel to the Y-axis direction. The pair of second electrode supports 269b are arranged on the same center line parallel to the Y-axis direction. The pair of third electrode supports 269c are arranged on the same center line parallel to the Y-axis direction. In the X-axis direction, the first electrode supports 269a, second electrode supports 269b, and third electrode supports 269c are arranged sequentially from the movable reflector 22 side.

[0071] The second elastic support 27 has a pair of levers 271, a first connecting member 272, a second connecting member 273, a pair of beam members 274, an intermediate member 275, a pair of first torsion bars (first torsion support) 276, a pair of second torsion bars (second torsion support) 277, a pair of nonlinear easing springs 278 and a plurality of electrode supports 279.

[0072] A pair of levers 271 are positioned on either side of the light-passing opening 25 along the Y-axis, facing each other in the Y-axis direction. Each lever 271 is plate-shaped, extending along a plane perpendicular to the Z-axis. Each lever 271 has a first portion 271a, a second portion 271b disposed opposite to the movable reflector 22 relative to the first portion 271a, and a third portion 271c connected to the first portion 271a and the second portion 271b. The first portion 271a and the second portion 271b extend along the X-axis direction. The length of the first portion 271a in the X-axis direction is shorter than the length of the second portion 271b in the X-axis direction. The third portion 271c of the pair of levers 271 extends obliquely, becoming increasingly separated from each other as they move further away from the movable reflector 22.

[0073] The first connecting member 272 is mounted between the first ends 271d of a pair of levers 271 on the opposite side of the movable reflector 22. The first connecting member 272 is plate-shaped, extending along a plane perpendicular to the Z-axis, and extends along the Y-axis. The second connecting member 273 is mounted between the second ends 271e of the pair of levers 271 on the movable reflector 22 side. The second connecting member 273 is plate-shaped, extending along a plane perpendicular to the Z-axis, and extends along the Y-axis. The width of the second connecting member 273 in the X-axis direction is narrower than the width of the first connecting member 272 in the X-axis direction. The length of the second connecting member 273 in the Y-axis direction is shorter than the length of the first connecting member 272 in the Y-axis direction.

[0074] A pair of beam members 274 are respectively mounted between the second portion 271b of a pair of levers 271 and the first connecting member 272. Each beam member 274 is plate-shaped and extends along a plane perpendicular to the Z-axis. The pair of beam members 274 extend obliquely, becoming closer to each other as they are farther away from the movable reflector 22. The pair of levers 271, the first connecting member 272, the second connecting member 273, and the pair of beam members 274 define a light-passing opening 25. The light-passing opening 25 is polygonal when viewed from the Z-axis. The light-passing opening 25 is, for example, a cavity (hole). Alternatively, a material that is translucent relative to the measuring light L0 and the laser L10 may be disposed within the light-passing opening 25.

[0075] The intermediate component 275 is a plate extending along a plane perpendicular to the Z-axis and along the Y-axis. The intermediate component 275 is disposed between the movable reflector 22 and the second connecting component 273 (in other words, between the movable reflector 22 and the light-passing opening 25). As described later, the intermediate component 275 is connected to the movable reflector 22 by a non-linear buffer spring 278.

[0076] A pair of first torsion bars 276 are respectively mounted between the first end 271d of one lever 271 and the base 21, and between the first end 271d of the other lever 271 and the base 21. That is, the pair of first torsion bars 276 are respectively connected between the pair of levers 271 and the base 21. Each first torsion bar 276 extends along the Y-axis direction. The pair of first torsion bars 276 are arranged on the same center line parallel to the Y-axis direction. In this embodiment, the center line of each first torsion bar 276 is on the same straight line as the center line of the first connecting member 272. A protrusion 271f protruding outward in the Y-axis direction is provided at the first end 271d of each lever 271, and each first torsion bar 276 is connected to the protrusion 271f.

[0077] A pair of second torsion bars 277 are respectively mounted between the second end 271e of one lever 271 and one end of the intermediate component 275, and between the second end 271e of the other lever 271 and the other end of the intermediate component 275. That is, the pair of second torsion bars 277 are respectively connected between the pair of levers 271 and the movable reflector 22. Each second torsion bar 277 extends along the Y-axis direction. The pair of second torsion bars 277 are arranged on the same center line parallel to the Y-axis direction.

[0078] A pair of nonlinear buffer springs 278 are connected between the movable reflector 22 and the intermediate member 275. Specifically, the pair of nonlinear buffer springs 278 are connected between the movable reflector 22 and the second torsion bar 277. Each nonlinear buffer spring 278 has a meandering portion 278a that extends meanderingly when viewed from the Z-axis direction. The meandering portion 278a includes a plurality of straight portions 278b extending in the Y-axis direction and arranged in the X-axis direction, and a plurality of folded portions 278c alternately connecting the two ends of the plurality of straight portions 278b. One end of the meandering portion 278a is connected to the intermediate member 275, and the other end of the meandering portion 278a is connected to the frame portion 222. The portion of the meandering portion 278a on the frame portion 222 side has a shape formed along the outer edge of the frame portion 222.

[0079] The nonlinear buffer spring 278 is configured such that, when the movable reflector 22 moves in the Z-axis direction, the deformation of the nonlinear buffer spring 278 around the Y-axis is less than the deformation of the first torsion bar 276 and the second torsion bar 277 around the Y-axis, and the deformation of the nonlinear buffer spring 278 in the X-axis direction is greater than the deformation of the first torsion bar 276 and the second torsion bar 277 in the X-axis direction. Therefore, nonlinearity arising from the torsional deformation of the first torsion bar 276 and the second torsion bar 277 can be suppressed, and the decrease in the control characteristics of the movable reflector 22 caused by this nonlinearity can be suppressed.

[0080] The plurality of electrode supports 279 include a pair of first electrode supports 279a, a pair of second electrode supports 279b, and a pair of third electrode supports 279c. Each electrode support 279a, 279b, and 279c is plate-shaped, extending along a plane perpendicular to the Z-axis direction and along the Y-axis direction. Each electrode support 279a, 279b, and 279c extends from the second portion 271b of the lever 271 toward the side opposite to the light-passing opening 25. The pair of first electrode supports 279a are arranged on the same center line parallel to the Y-axis direction. The pair of second electrode supports 279b are arranged on the same center line parallel to the Y-axis direction. The pair of third electrode supports 279c are arranged on the same center line parallel to the Y-axis direction. In the X-axis direction, the first electrode supports 279a, second electrode supports 279b, and third electrode supports 279c are arranged sequentially from the movable reflector 22 side.

[0081] The actuator unit 28 moves the movable reflector 22 along the Z-axis. The actuator unit 28 includes a fixed comb electrode 281, a movable comb electrode 282, a fixed comb electrode 283, and a movable comb electrode 284. The positions of the fixed comb electrodes 281 and 283 are fixed. The movable comb electrodes 282 and 284 move with the movement of the movable reflector 22.

[0082] The fixed comb electrode 281 is disposed on a portion of the surface of the device layer 102 of the substrate 21 facing the electrode support portion 269. The fixed comb electrode 281 has a plurality of fixed comb teeth 281a extending along a plane perpendicular to the Y-axis direction. These fixed comb teeth 281a are arranged side by side with a predetermined interval in the Y-axis direction.

[0083] Movable comb electrodes 282 are provided on the surfaces of the movable reflectors 22 side of each first electrode support 269a, on both sides of each second electrode support 269b in the X-axis direction, and on the surfaces of the movable reflectors 22 side of each third electrode support 269c. Each movable comb electrode 282 has a plurality of movable comb teeth 282a extending along a plane perpendicular to the Y-axis direction. These movable comb teeth 282a are arranged side-by-side with predetermined intervals in the Y-axis direction.

[0084] In the fixed comb electrode 281 and the movable comb electrode 282, multiple fixed comb teeth 281a and multiple movable comb teeth 282a are alternately arranged. That is, each fixed comb tooth 281a of the fixed comb electrode 281 is located between the movable comb teeth 282a of the movable comb electrode 282. Adjacent fixed comb teeth 281a and movable comb teeth 282a face each other in the Y-axis direction. The distance between adjacent fixed comb teeth 281a and movable comb teeth 282a is, for example, about a few μm.

[0085] The fixed comb electrode 283 is disposed on a portion of the surface of the device layer 102 of the substrate 21 facing the electrode support portion 279. The fixed comb electrode 283 has a plurality of fixed comb teeth 283a extending along a plane perpendicular to the Y-axis direction. These fixed comb teeth 283a are arranged side by side with a predetermined interval in the Y-axis direction.

[0086] Movable comb electrodes 284 are provided on the surfaces of the movable reflectors 22 side of each first electrode support 279a, on both sides of each second electrode support 279b in the X-axis direction, and on the surfaces of the movable reflectors 22 side of each third electrode support 279c. Each movable comb electrode 284 has a plurality of movable comb teeth 284a extending along a plane perpendicular to the Y-axis direction. These movable comb teeth 284a are arranged side-by-side with predetermined intervals in the Y-axis direction.

[0087] In the fixed comb electrode 283 and the movable comb electrode 284, multiple fixed comb teeth 283a and multiple movable comb teeth 284a are alternately arranged. That is, each fixed comb tooth 283a of the fixed comb electrode 283 is located between the movable comb teeth 284a of the movable comb electrode 284. Adjacent fixed comb teeth 283a and movable comb teeth 284a face each other in the Y-axis direction. The distance between adjacent fixed comb teeth 283a and movable comb teeth 284a is, for example, about a few μm.

[0088] A plurality of electrode pads 211 are provided on the substrate 21. Each electrode pad 211 is disposed on the surface of the device layer 102 within an opening 213 formed in the first surface 21a of the substrate 21 such that it reaches the device layer 102. Some of the electrode pads 211 are electrically connected to the fixed comb electrode 281 or fixed comb electrode 283 through the device layer 102. Other of the electrode pads 211 are electrically connected to the movable comb electrode 282 or movable comb electrode 284 through the first elastic support portion 26 or the second elastic support portion 27. In addition, a pair of electrode pads 212 used as ground electrodes are provided on the substrate 21. The pair of electrode pads 212 are disposed on the first surface 21a such that they are located on both sides of the movable reflector 22 in the Y-axis direction.

[0089] Reference Figure 11 The structure around the electrode pad 211 will be further explained below. The following description refers to one electrode pad 211, but other electrode pads 211 are constructed similarly. Figure 11 As shown, each electrode pad 211 is disposed on the surface 102a of the support layer 102 in the Z-axis direction, within an opening 213 formed in the surface 101a of the support layer 101 in such a way as to reach the device layer 102.

[0090] The opening 213 has a bottom surface 214 formed by a surface 102a and a side surface 215 formed by a support layer 101 and an intermediate layer 103. The bottom surface 214 is, for example, rectangular. The side surface 215 has a first surface 215a that is continuously formed with the bottom surface 214 and extends substantially perpendicular to the bottom surface 214, a step surface 215b that is continuously formed with the first surface 215a and extends substantially parallel to the bottom surface 214, and a second surface 215c that is continuously formed with the step surface 215b and extends substantially perpendicular to the bottom surface 214. The step surface 215b extends in a ring shape along the edge of the opening 213 when viewed from the Z-axis direction.

[0091] Electrode pad 211 is disposed across the entire surface of bottom surface 214. Furthermore, electrode pad 211 extends across bottom surface 214 and side surface 215. More specifically, electrode pad 211 is formed such that it reaches the first surface 215a of side surface 215 but not the stepped surface 215b. Electrode pad 211 is, for example, made of a metal film (metal layer). This metal film is formed, for example, by sputtering using a hard mask. The metal film constituting electrode pad 211 is thicker than the metal film constituting mirror surface 22a.

[0092] The substrate 21 has a groove 216 formed on the surface 101a of the support layer 101, extending to the device layer 102. The groove 216 extends in a ring shape, surrounding the opening 213 when viewed from the Z-axis direction. For example, the groove 216 is rectangular ring-shaped when viewed from the Z-axis direction. By providing the groove 216, the electrode pads 211 can be reliably electrically insulated from each other. That is, as in this embodiment, the metal film constituting the electrode pads 211 is formed to the side 215, and when the electrode pads 211 are in contact with the support layer 101, there is a problem that the electrode pads 211 are electrically connected to each other through the support layer 101. In contrast, in the mirror device 20, by providing the groove 216, the electrode pads 211 can be reliably electrically insulated from each other even in such a case.

[0093] In the mirror device 20 configured as described above, an electrical signal for moving the movable mirror 22 along the Z-axis direction is input to the drive unit 23 via the pin 113 and cable (not shown). This generates electrostatic forces, for example, between the opposing fixed comb electrode 281 and the movable comb electrode 282, and between the opposing fixed comb electrode 283 and the movable comb electrode 284, causing the movable mirror 22 to move to one side in the Z-axis direction. At this time, the first torsion bars 266 and 276 and the second torsion bars 267 and 277 twist in the first elastic support 26 and the second elastic support 27, generating elastic forces in the first elastic support 26 and the second elastic support 27. In the mirror device 20, by supplying a periodic electrical signal to the drive unit 23, the movable mirror 22 can be horizontally reciprocated along the Z-axis at its resonant frequency. Thus, the drive unit 23 functions as an electrostatic actuator.

[0094] [Other structures of the mirror unit]

[0095] like Figure 2 , Figure 3 , Figure 4 and Figure 7As shown, the optical functional component 13 has a third surface 13a (a surface on one side in the Z-axis direction) opposite to the second surface 21b of the substrate 21, and a fourth surface 13b opposite to the third surface 13a. The optical functional component 13 is disposed on the other side in the Z-axis direction relative to the mirror device 20. When viewed from the Z-axis direction, the outer edge 13c of the optical functional component 13 is located outside the outer edge 21c of the substrate 21. That is, when viewed from the Z-axis direction, the outer edge 13c of the optical functional component 13 surrounds the outer edge 21c of the substrate 21. The optical functional component 13 is integrally formed of a material that is transmissive to the measurement light L0 and the laser L10. The optical functional component 13 is formed, for example, in the shape of a rectangular plate of glass, for example, having dimensions of about 15mm × 20mm × 4mm (thickness). In addition, the material of the optical functional component 13 is selected, for example, according to the sensitivity wavelength of the optical component 1; glass is used when the sensitivity wavelength of the optical component 1 is in the near-infrared region, and silicon is used when the sensitivity wavelength of the optical component 1 is in the mid-infrared region.

[0096] A pair of light-transmitting portions 14 and 15 are provided in the optical functional component 13. The light-transmitting portion 14 is the part of the optical functional component 13 that faces the light-passing opening 24 of the reflector device 20 in the Z-axis direction. The light-transmitting portion 15 is the part of the optical functional component 13 that faces the light-passing opening 25 of the reflector device 20 in the Z-axis direction. The reflector device 20-side surface 14a of the light-transmitting portion 14 and the reflector device 20-side surface 15a of the light-transmitting portion 15 are located on the same plane as the third surface 13a. The light-transmitting portion (second light-passing portion) 14 constitutes the second part (a portion) of the optical path between the beam splitter unit 3 and the fixed reflector 16. The light-transmitting portion 14 is the portion that corrects the optical path difference generated between the optical path between the beam splitter unit 3 and the movable reflector 22 and the optical path between the beam splitter unit 3 and the fixed reflector 16. However, in this embodiment, the light-transmitting portion 15 does not function as a light-transmitting portion.

[0097] The optical functional component 13 has a fifth surface 13d opposite to the movable mirror 22 and the drive unit 23 of the mirror device 20. The fifth surface 13d is located on the side closer to the fourth surface 13b than the third surface 13a. The fifth surface 13d extends to the outer edge 13c of the optical functional component 13 when viewed from the Z-axis direction. In this embodiment, the fifth surface 13d surrounds the ends of each light transmission part 14, 15 on the mirror device 20 side, and extends to a pair of opposite sides extending in the Y-axis direction in the outer edge 13c of the optical functional component 13.

[0098] The third surface 13a of the optical functional component 13 is bonded to the second surface 21b of the substrate 21 by direct bonding (e.g., plasma activation bonding, surface-activated room-temperature bonding (SAB), atomic diffusion bonding (ADB), anodic bonding, fusion bonding, hydrophilic bonding, etc.). In this embodiment, the third surface 13a extends on both sides of the fifth surface 13d in the Y-axis direction, opposite to the plurality of electrode pads 211, 212 disposed on the substrate 21. Here, the fifth surface 13d is located closer to the fourth surface 13b than the third surface 13a, so the fifth surface 13d leaves the mirror device 20 in the region opposite to the movable mirror 22 and the drive unit 23. Furthermore, the surfaces 14a of the light-transmitting section 14 and 15a of the light-transmitting section 15 are respectively opposite to the light-passing openings 24 and 25 of the reflector device 20. Thus, the reflector unit 2 prevents the movable reflector 22 and the drive section 23 from contacting the optical functional component 13 when the movable reflector 22 reciprocates along the Z-axis direction.

[0099] Furthermore, a sixth surface 21d is provided on the substrate 21 of the reflector device 20, which exits the optical functional component 13 when the third surface 13a of the optical functional component 13 is engaged with the second surface 21b of the substrate 21. The sixth surface 21d exits the optical functional component 13 in a region including at least a portion of the outer edge of the substrate 21 when viewed from the Z-axis direction. In this embodiment, the sixth surface 21d is formed by etching away the device layer 102 and the intermediate layer 103 along one edge extending in the Y-axis direction along the outer edge of the substrate 21. Additionally, a plurality of reference holes 13e are formed on the third surface 13a of the optical functional component 13. In this embodiment, the plurality of reference holes 13e are formed on the third surface 13a in such a manner that they correspond to a plurality of corner portions of the substrate 21. When the third surface 13a of the optical functional component 13 and the second surface 21b of the substrate 21 are engaged with each other, the mirror device 20 is operated by holding the part of the substrate 21 corresponding to the sixth surface 21d. The position of the mirror device 20 in the X-axis direction and the Y-axis direction and the angle of the mirror device 20 in the plane perpendicular and parallel to the Z-axis direction are adjusted with reference to the plurality of reference holes 13e formed on the third surface 13a.

[0100] like Figure 3 and Figure 4As shown, the fixed reflector 16 is disposed on the opposite side of the optical functional component 13 in the Z-axis direction (opposite to the reflector device 20), and its position is fixed relative to the substrate 21 of the reflector device 20. The fixed reflector 16 is formed, for example, by vapor deposition on the fourth surface 13b of the optical functional component 13. The fixed reflector 16 has a reflective surface 16a perpendicular to the Z-axis direction. In this embodiment, the reflective surface 22a of the movable reflector 22 and the reflective surface 16a of the fixed reflector 16 face one side in the Z-axis direction (beam splitter unit 3 side). In addition, the fixed reflector 16 is continuously formed with the fourth surface 13b of the optical functional component 13 in such a way as to reflect the light transmitted from each light transmission portion 14, 15 of the optical functional component 13. However, it is also possible to provide a fixed reflector that reflects the light transmitted from the light transmission portion 14 and a fixed reflector that reflects the light transmitted from the light transmission portion 15, respectively.

[0101] The stress-relieving substrate 17 is mounted on the fourth surface 13b of the optical functional component 13 via a fixed mirror 16. The stress-relieving substrate 17 is mounted on the fixed mirror 16, for example, using an adhesive. Viewed from the Z-axis, the outer edge of the stress-relieving substrate 17 is located outside the outer edge 13c of the optical functional component 13. That is, viewed from the Z-axis, the outer edge of the stress-relieving substrate 17 surrounds the outer edge 13c of the optical functional component 13. The coefficient of thermal expansion of the stress-relieving substrate 17 is closer to that of the substrate 21 of the mirror device 20 (more specifically, the coefficient of thermal expansion of the support layer 101) than that of the optical functional component 13. Furthermore, the thickness of the stress-relieving substrate 17 is closer to that of the substrate 21 of the mirror device 20 than the thickness of the optical functional component 13. The stress-relieving substrate 17 is formed, for example, in a rectangular plate shape using silicon, and has dimensions of approximately 16 mm × 21 mm × 0.65 mm (thickness).

[0102] In the mirror unit 2 constructed as described above, such as Figure 1 As shown, the surface of the stress-relieving substrate 17 opposite to the optical functional component 13 is fixed to the surface 9a (one side of the surface in the Z-axis direction) of the support 9 by adhesive, thereby mounting it on the support 9. When the mirror unit 2 is mounted on the support 9, as... Figure 8 As shown, using the reference hole 9b formed in the support 9 as a reference, the positions of the reflector devices 20 in the X-axis and Y-axis directions and the angle of the reflector devices 20 in the plane perpendicular and parallel to the Z-axis direction are adjusted. Furthermore, in Figure 8 The illustration of the second support structure 12 is omitted.

[0103] [Structure of the first support structure and beam splitter unit]

[0104] like Figure 1 and Figure 8As shown, the first support structure 11 includes a frame 111, a light-transmitting component 112, and a plurality of pins 113. The frame 111 is formed to surround the mirror unit 2 when viewed from the Z-axis direction, and is mounted on the surface 9a of the support body 9, for example, by an adhesive such as silver solder. The frame 111 is formed of ceramic, for example, and is rectangular in shape. The end face 111a of the frame 111 opposite to the support body 9 is located further opposite to the support body 9 than the first surface 21a of the base 21 of the mirror device 20.

[0105] The light transmission component 112 is formed in a manner that closes the opening of the frame 111, for example, by being attached to the end face 111a of the frame 111 with an adhesive. The light transmission component 112 is formed of a material that is transmissive to the measurement light L0 and the laser L10, for example, in the shape of a rectangular plate. Here, the end face 111a of the frame 111 is located on the opposite side to the support 9 compared to the first surface 21a of the base 21 of the reflector device 20, so the light transmission component 112 is separated from the reflector device 20. Thus, the optical assembly 1 prevents the movable reflector 22 and the drive unit 23 from contacting the light transmission component 112 when the movable reflector 22 reciprocates along the Z-axis direction. In addition, in the optical assembly 1, the support 9, the frame 111, and the light transmission component 112 constitute an encapsulation for housing the reflector unit 2.

[0106] Each pin 113 is disposed in the frame 111 with one end 113a located inside the frame 111 and the other end (not shown) located outside the frame 111. One end 113a of the pin 113 is electrically connected to the electrode pads 211, 212 corresponding to the pin 113 in the reflector device 20 via a cable (not shown). In the optical assembly 1, an electrical signal for moving the movable reflector 22 along the Z-axis direction is input to the drive unit 23 through the plurality of pins 113. In this embodiment, a step surface 111b extending along the X-axis direction on both sides of the optical functional component 13 in the Y-axis direction is formed in the frame 111, and one end 113a of each pin 113 is disposed on the step surface 111b. Each pin 113 extends along the Z-axis direction on both sides of the support body 9 in the Y-axis direction, and the other end of each pin 113 is located on the opposite side of the support body 9 in the Z-axis direction.

[0107] like Figure 10 As shown, the beam splitter unit 3 is mounted, for example, on the surface 112a of the light transmission component 112 opposite to the mirror device 20 using an optical adhesive that also acts as a refractive index matching agent. The beam splitter unit 3 has a first mirror surface 31, a second mirror surface 32, and multiple optical surfaces 33a, 33b, 33c, and 33d. The beam splitter unit 3 is constructed by joining multiple optical blocks 34 and 35. Each optical block 34 and 35 is formed of a material with the same or similar refractive index as the optical functional component 13. Furthermore, Figure 10 yes Figure 1The schematic cross-sectional view of the reflector unit 2 and the beam splitter unit 3 shown is in... Figure 10 In the example, the reflector device 20 is schematically represented with its size enlarged in the Z-axis direction to a size larger than the actual size.

[0108] The first reflecting mirror surface 31 is a reflecting mirror surface (e.g., a semi-reflecting mirror surface) that is inclined relative to the Z-axis direction, and is formed between optical block 34 and optical block 35. In this embodiment, the first reflecting mirror surface 31 is a surface parallel to the Y-axis direction and at a 45° angle to the Z-axis direction, and is inclined in such a way that the closer to the reflecting mirror device 20, the further away from the light incident portion 4. The first reflecting mirror surface 31 has the function of reflecting a portion of the measurement light L0 and transmitting the remaining portion of the measurement light L0, and the function of reflecting a portion of the laser L10 and transmitting the remaining portion of the laser L10. The first reflecting mirror surface 31 is formed, for example, from a dielectric multilayer film. When viewed from the Z-axis direction, the first reflecting mirror surface 31 overlaps with the reflecting mirror surface 16a of the light transmission portion 14 of the optical functional component 13 and the fixed reflecting mirror 16 of the reflecting mirror device 20, and overlaps with the light incident portion 4 when viewed from the X-axis direction (see reference). Figure 1 That is, the first reflecting mirror 31 is opposite to the fixed reflecting mirror 16 in the Z-axis direction and opposite to the light incident part 4 in the X-axis direction.

[0109] The second reflecting mirror 32 is a reflecting mirror (e.g., a total internal reflection mirror) parallel to the first reflecting mirror 31, and is formed on the optical block 35 in such a way that it is located on the opposite side of the light incident section 4 relative to the first reflecting mirror 31. The second reflecting mirror 32 has the functions of reflecting the measurement light L0 and reflecting the laser L10. The second reflecting mirror 32 is formed, for example, by a metal film. When viewed from the Z-axis direction, the second reflecting mirror 32 overlaps with the reflecting mirror 22a of the movable reflecting mirror 22 of the reflecting mirror device 20, and when viewed from the X-axis direction, it overlaps with the first reflecting mirror 31. That is, the second reflecting mirror 32 is opposite to the movable reflecting mirror 22 in the Z-axis direction and opposite to the first reflecting mirror 31 in the X-axis direction.

[0110] Optical surface 33a is a surface perpendicular to the Z-axis direction, formed in optical block 35 on the opposite side of the first reflecting mirror surface 31 from the reflecting mirror device 20. Optical surface 33b is a surface perpendicular to the Z-axis direction, formed in optical block 35 on the side of the reflecting mirror device 20 relative to the second reflecting mirror surface 32. Optical surface 33c is a surface perpendicular to the Z-axis direction, formed in optical block 34 on the side of the reflecting mirror device 20 relative to the first reflecting mirror surface 31. Optical surfaces 33b and 33c are located on the same plane. Optical surface 33d is a surface perpendicular to the X-axis direction, formed in optical block 34 on the side of the light incident section 4 relative to the first reflecting mirror surface 31. Each optical surface 33a, 33b, 33c, and 33d has the function of transmitting the measurement light L0 and the function of transmitting the laser L10.

[0111] The beam splitter unit 3, configured as described above, is mounted on the light transmission component 112 by means of optical surfaces 33b and 33c located on the same plane, for example, using an optical adhesive to fix them to the surface 112a of the light transmission component 112. When mounting the beam splitter unit 3 on the light transmission component 112, as... Figure 9 As shown, using the reference hole 9b formed in the support 9 as a reference, the positions of the beam splitter units 3 in the X-axis and Y-axis directions and the angle of the beam splitter units 3 in the plane perpendicular and parallel to the Z-axis direction are adjusted. Furthermore, in Figure 9 The illustration of the second support structure 12 is omitted.

[0112] Here, refer to Figure 10 The optical paths of the measurement light L0 and the laser L10 of the reflector unit 2 and the beam splitter unit 3 are described in detail.

[0113] like Figure 10As shown, when the measurement light L0 is incident on the beam splitter unit 3 along the X-axis direction through the optical surface 33d, a portion of the measurement light L0 is transmitted from the first reflecting mirror surface 31, reflected by the second reflecting mirror surface 32, and reaches the reflecting mirror surface 22a of the movable reflecting mirror 22 through the optical surface 33b and the light transmission component 112. A portion of the measurement light L0 is reflected by the reflecting mirror surface 22a of the movable reflecting mirror 22, travels in the opposite direction along the same optical path P1, and is reflected again by the first reflecting mirror surface 31. The remaining portion of the measurement light L0 is reflected by the first reflecting mirror surface 31, and the light passing through the optical surface 33c, the light transmission component 112, and the reflecting mirror device 20 passes through the opening 24 and the light transmission portion 14 of the optical functional component 13, reaching the reflecting mirror surface 16a of the fixed reflecting mirror 16. The remaining portion of the measurement light L0 is reflected by the reflecting mirror surface 16a of the fixed reflecting mirror 16, travels in the opposite direction along the same optical path P2, and is transmitted from the first reflecting mirror surface 31. A portion of the measurement light L0 reflected by the first reflecting mirror 31 and the remaining portion of the measurement light L0 transmitted from the first reflecting mirror 31 become the interference light L1. The interference light L1 of the measurement light is emitted from the beam splitter unit 3 along the Z-axis direction through the optical surface 33a.

[0114] On the other hand, when laser L10 is incident on beam splitter unit 3 along the Z-axis direction through optical surface 33a, a portion of laser L10 is reflected by the first reflecting mirror surface 31 and the second reflecting surface 32, and reaches the reflecting mirror surface 22a of movable mirror 22 through optical surface 33b and light transmission component 112. A portion of laser L10 is reflected by the reflecting mirror surface 22a of movable mirror 22, travels in the opposite direction along the same optical path P3, and is reflected by the first reflecting mirror surface 31. The remaining portion of laser L10 is transmitted from the first reflecting mirror surface 31, and the light passing through optical surface 33c, light transmission component 112, and reflecting mirror device 20 passes through opening 24 and light transmission portion 14 of optical functional component 13, reaching the reflecting mirror surface 16a of fixed mirror 16. The remaining portion of laser L10 is reflected by the reflecting mirror surface 16a of fixed mirror 16, travels in the opposite direction along the same optical path P4, and is transmitted from the first reflecting mirror surface 31. A portion of the laser L10 reflected by the first reflecting mirror 31 and the remaining portion of the laser L10 transmitted from the first reflecting mirror 31 become interference light L11. The interference light L11 of this laser is emitted from the beam splitter unit 3 along the Z-axis direction through the optical surface 33a.

[0115] As described above, the light from the reflector device 20 passes through the opening 24 and forms the first part P2a of the optical path P2 of the measurement light L0 and the first part P4a of the optical path P4 of the laser L10 in the optical path between the beam splitter unit 3 and the fixed reflector 16. Furthermore, the light transmission section 14 of the optical functional component 13 forms the second part P2b of the optical path P2 of the measurement light L0 and the second part P4b of the optical path P4 of the laser L10 in the optical path between the beam splitter unit 3 and the fixed reflector 16.

[0116] By constructing the second part P2b of the optical path P2 for measuring light L0 using the light transmission section 14, the optical path difference between the two optical paths P1 and P2 is corrected, thereby reducing the difference between the optical path length of the optical path P1 (which takes into account the refractive index of each medium through which the optical path passes) and the optical path length of the optical path P2 for measuring light L0. Similarly, by constructing the second part P4b of the optical path P4 for laser L10 using the light transmission section 14, the optical path difference between the two optical paths P3 and P4 is corrected, thereby reducing the difference between the optical path length of the optical path P3 and the optical path length of the optical path P4 for laser L10. In this embodiment, the refractive index of the light transmission section 14 is equal to the refractive index of each optical block constituting the beam splitter unit 3, and the distance between the first reflecting mirror surface 31 and the second reflecting mirror surface 32 along the X-axis direction is equal to the thickness of the light transmission section 14 along the Z-axis direction (i.e., the distance between the surface 14a of the light transmission section 14 along the Z-axis direction and the fourth surface 13b of the optical functional component 13).

[0117] [Structure of the second support structure and light incident section, etc.]

[0118] like Figure 1 As shown, the second support structure 12 has a connecting unit 120. The connecting unit 120 includes a main body 121, a frame 122, and a fixing plate 123. The main body 121 includes a pair of sidewall portions 124 and 125 and a top wall portion 126. The pair of sidewall portions 124 and 125 are opposite to each other in the X-axis direction. An opening 124a is formed on one side of the sidewall portion 124 in the X-axis direction. The top wall portion 126 is opposite to the support body 9 in the Z-axis direction. An opening 126a is formed in the top wall portion 126. The main body 121 is integrally formed, for example, using metal. A plurality of positioning pins 121a are provided in the main body 121. The main body 121 is positioned relative to the support body 9 by inserting the positioning pins 121a into the reference holes 9b and 9c formed in the support body 9, respectively, in this state, for example, by bolts.

[0119] The frame 122 is disposed on the surface of the side wall portion 124 opposite to the beam splitter unit 3. The opening of the frame 122 is opposite to the beam splitter unit 3 through the opening 124a of the side wall portion 124. A light incident portion 4 is disposed in the frame 122. The fixing plate 123 is a component for fixing the light incident portion 4 disposed in the frame 122 to the main body portion 121 (details will be described later).

[0120] The second support structure 12 further includes a retaining unit 130. The retaining unit 130 includes a main body 131, a frame 132, and a fixing plate 133. The main body 131 is mounted on the surface of the top wall portion 126 opposite to the support body 9. The main body 131 is positioned relative to the main body 121 of the connecting unit 120 by a plurality of positioning pins 131a, in which case it is mounted on the top wall portion 126, for example, by bolts. A recess 134 is formed on the surface of the main body 131 opposite to the support body 9. A first light-passing hole 135, a second light-passing hole 136, and a third light-passing hole 137 are formed on the bottom surface of the recess 134. The first light-passing hole 135 is formed in the Z-axis direction at a position opposite to the first reflecting mirror surface 31 of the beam splitter unit 3. The second light-passing hole 136 is formed in the X-axis direction on the other side of the first light-passing hole 135 (i.e., opposite to the light incident portion 4). The third light passes through aperture 137 and is formed on the other side of the second light passing through aperture 136 in the X-axis direction.

[0121] A frame 132 is disposed on the bottom surface of a recess 134. The opening of the frame 132 faces the third light-passing hole 137. A second light source 7 is disposed on the frame 132. A first photodetector 6 is disposed on the bottom surface of the recess 134 facing the first light-passing hole 135. A second photodetector 8 is disposed on the bottom surface of the recess 134 facing the second light-passing hole 136. A fixing plate 133 is a component used to fix the first photodetector 6 and the second photodetector 8 disposed on the bottom surface of the recess 134, and the second light source 7 disposed on the frame 132, to the main body 131 (details will be described later).

[0122] The light incident section 4 includes a holding member 41 and a collimating lens 42. The holding member 41 holds the collimating lens 42 in a configuration that allows connection to an optical fiber (not shown) that guides the measurement light L0. The collimating lens 42 collimates (calibrates) the measurement light L0 emitted from the optical fiber. When the optical fiber is connected to the holding member 41, the optical axis of the optical fiber is aligned with the optical axis of the collimating lens 42.

[0123] A flange 41a is provided on the retaining member 41. The flange 41a is disposed between the frame 122 and the fixing plate 123. In this state, the fixing plate 123 is installed on the side wall portion 124 by bolts, for example, so that the light incident portion 4 disposed on the frame 122 is fixed to the main body portion 121. In this way, the light incident portion 4 is disposed on one side of the beam splitter unit 3 in the X-axis direction and is supported by the second support structure 12. The light incident portion 4 allows the measurement light L0 incident from the first light source through the measurement object or the measurement light L0 emitted from the measurement object (in this embodiment, the measurement light L0 guided by the optical fiber) to enter the beam splitter unit 3.

[0124] A filter 54 is installed in the frame 122. The filter 54 has the function of blocking the laser L10. The filter 54 is disposed in the opening 124a of the side wall portion 124 with an inclination relative to the optical axis of the light incident portion 4. The filter 54 closes the opening of the frame 122 when viewed from the X-axis direction. Thus, the filter 54 is disposed between the light incident portion 4 and the beam splitter unit 3, and is supported by the second support structure 12 with an inclination relative to the optical axis of the light incident portion 4. In this embodiment, the optical surface of the filter 54 is a surface parallel to the Z-axis direction and a surface at an angle of 10° to 20° to the Y-axis direction. In addition, the optical axis of the light incident portion 4 is parallel to the X-axis direction.

[0125] Therefore, even if the measurement light L0 contains light of the same wavelength as the laser L10, this light can be prevented from incident on the beam splitter unit 3. Thus, based on the detection result of the interference light L11 of the laser, the position of the movable mirror 22 in the Z-axis direction can be obtained with high precision. Furthermore, since the filter 54 is tilted relative to the optical axis of the light incident section 4, light of the same wavelength as the laser L10 can be reflected outside the interference optical system, thereby reliably preventing this light from becoming stray light. In this embodiment, light of the same wavelength as the laser L10 emitted from the beam splitter unit 3 along the X-axis direction is reflected by the filter 54 and exits outside the interference optical system between a pair of sidewall portions 124 and 125 of the main body portion 121 of the second support structure 12. Therefore, this light can be reliably prevented from becoming stray light.

[0126] The first photodetector 6 has a holding member 61, a photodetector element 62, and a condenser lens 63. The holding member 61 holds the photodetector element 62 and the condenser lens 63. The photodetector element 62 detects the interference light L1 of the measurement light. The photodetector element 62 is, for example, an InGaAs photodiode. The condenser lens 63 focuses the interference light L1 of the measurement light incident on the photodetector element 62 onto the photodetector element 62. In the holding member 61, the optical axis of the photodetector element 62 is aligned with the optical axis of the condenser lens 63.

[0127] A flange 61a is provided on the retainer 61. The flange 61a is disposed between the bottom surface of the recess 134 of the main body 131 and the fixing plate 133. In this state, the fixing plate 133 is mounted on the main body 131, for example, by bolts, and the first photodetector 6 disposed on the bottom surface of the recess 134 is fixed to the main body 131. Thus, the first photodetector 6 is disposed on one side of the beam splitter unit 3 in the Z-axis direction and is supported by the second support structure 12. The first photodetector 6 is opposite to the first reflecting mirror surface 31 of the beam splitter unit 3 in the Z-axis direction. The first photodetector 6 detects the interference light L1 of the measurement light emitted from the beam splitter unit 3.

[0128] The second photodetector 8 has a holding member 81, a photodetector element 82, and a condenser lens 83. The holding member 81 holds the photodetector element 82 and the condenser lens 83. The photodetector element 82 detects the interference light L11 of the laser. The photodetector element 82 is, for example, a Si photodiode. The condenser lens 83 directs the interference light L11 of the laser incident on the photodetector element 82 to the photodetector element 82. In the holding member 81, the optical axis of the focused light from the photodetector element 82 is aligned with the optical axis of the condenser lens 83.

[0129] A flange 81a is provided on the retainer 81. The flange 81a is disposed between the bottom surface of the recess 134 of the main body 131 and the fixing plate 133. In this state, the fixing plate 133 is mounted on the main body 131, for example, by bolts, and the second photodetector 8 disposed on the bottom surface of the recess 134 is fixed to the main body 131. Thus, the second photodetector 8 is disposed on one side of the beam splitter unit 3 in the Z-axis direction and is supported by the second support structure 12. The second photodetector 8 detects the interference light L11 of the laser emitted from the beam splitter unit 3.

[0130] The second light source 7 has a holding member 71, a light-emitting element 72, and a collimating lens 73. The holding member 71 holds the light-emitting element 72 and the collimating lens 73. The light-emitting element 72 emits laser light L10. The light-emitting element 72 is, for example, a semiconductor laser such as a VCSEL. The collimating lens 73 collimates the laser light L10 emitted from the light-emitting element 72. In the holding member 71, the optical axis of the light-emitting element 72 is aligned with the optical axis of the collimating lens 73.

[0131] A flange 71a is provided on the retainer 71. The flange 71a is disposed between the frame 132 and the fixing plate 133. In this state, the fixing plate 133 is mounted on the main body 131, for example, by bolts, and the second light source 7 disposed on the frame 132 is fixed to the main body 131. Thus, the second light source 7 is disposed on one side of the beam splitter unit 3 in the Z-axis direction and is supported by the second support structure 12. The second light source 7 emits laser L10 that is incident on the beam splitter unit 3.

[0132] As described above, the holding unit 130 holds the first photodetector (first optical device) 6, the second photodetector (second optical device) 8, and the second light source (third optical device) 7 facing the same side and arranged in the order of first photodetector 6, second photodetector 8, and second light source 7. In this embodiment, the holding unit 130 holds the first photodetector 6, the second photodetector 8, and the second light source 7 on one side of the beam splitter unit 3 in the Z-axis direction, such that the first photodetector 6, the second photodetector 8, and the second light source 7 face the other side in the Z-axis direction (i.e., the beam splitter unit 3 side). Furthermore, the holding unit 130 holds the first photodetector 6, the second photodetector 8, and the second light source 7 in the order of first photodetector 6, second photodetector 8, and second light source 7, starting from one side in the X-axis direction (i.e., the light incident section 4 side).

[0133] A first reflector 51, a second reflector 52, and a third reflector 53 are mounted on the main body 131 of the holding unit 130. The first reflector 51 is held by the holding unit 130 and is located on the opposite side of the first photodetector 6 relative to the first light-passing aperture 135. The second reflector 52 is held by the holding unit 130 and is located on the opposite side of the second photodetector 8 relative to the second light-passing aperture 136. The third reflector 53 is held by the holding unit 130 and is located on the opposite side of the second light source 7 relative to the third light-passing aperture 137.

[0134] The first reflecting mirror 51 has the function of transmitting the measurement light L0 and reflecting the laser L10, and is a dichroic mirror tilted relative to the optical axis of the first photodetector 6. The first reflecting mirror 51 is disposed between the beam splitter unit 3 and the first photodetector 6. That is, the first reflecting mirror 51 is disposed opposite to the beam splitter unit 3 and the first photodetector 6. In this embodiment, the optical surface of the first reflecting mirror 51 is a surface parallel to the Y-axis direction and a surface forming a 45° angle with the Z-axis direction. In addition, the optical axis of the first photodetector 6 is parallel to the Z-axis direction.

[0135] The second reflector 52 has the function of reflecting a portion of the laser L10 and transmitting the remaining portion of the laser L10, and is a reflector (e.g., a half-reflector) parallel to the first reflector 51. The second reflector 52 is configured to overlap with the first reflector 51 when viewed from the X-axis direction and with the second photodetector 8 when viewed from the Z-axis direction. That is, the second reflector 52 is configured opposite to the first reflector 51 and the second photodetector 8. In this embodiment, the optical surface of the second reflector 52 is a surface parallel to the Y-axis direction and forms a 45° angle with the Z-axis direction.

[0136] The third reflector 53 has the function of reflecting laser L10 and is a reflector (e.g., a total reflection mirror) parallel to the second reflector 52. The third reflector 53 is arranged such that it overlaps with the second reflector 52 when viewed from the X-axis direction and overlaps with the second light source 7 when viewed from the Z-axis direction. That is, the third reflector 53 is arranged opposite to the second reflector 52 and the second light source 7. In this embodiment, the optical surface of the third reflector 53 is a surface parallel to the Y-axis direction and a surface forming a 45° angle with the Z-axis direction.

[0137] An aperture component 55 is mounted on the main body 131 of the holding unit 130. The aperture component 55 is held by the holding unit 130 and is located between the first reflector 51 and the first photodetector 6. The aperture component 55 is a component with a circular opening when viewed from the Z-axis direction and is disposed within the first light transmission hole 135.

[0138] The interference light L1 of the measurement light emitted from beam splitter unit 3 along the Z-axis is transmitted through the first reflector 51, passes through the aperture member 55, and is incident on the first photodetector 6, where it is detected. On the other hand, the laser L10 emitted from the second light source 7 is reflected by the third reflector 53 and transmitted through the second reflector 52, then reflected by the first reflector 51 and incident on the beam splitter unit 3 along the Z-axis. The interference light L11 of the laser emitted from beam splitter unit 3 along the Z-axis is reflected by both the first reflector 51 and the second reflector 52 and incident on the second photodetector 8, where it is detected.

[0139] [Functions and Effects]

[0140] In the mirror device 20 described above, the first surface 21a (the surface on one side in the Z-axis direction) of the substrate 21 is positioned further to one side than the mirror surface 22a. Therefore, the substrate 21 can protect the mirror surface 22a, for example, suppressing damage to the mirror surface 22a due to direct contact during handling, etc. Furthermore, in the mirror device 20, the support layer 101 constituting the substrate 21 is thicker than the device layer 102 constituting the substrate 21. Therefore, the amount of protrusion of the substrate 21 relative to the mirror surface 22a can be ensured, and the mirror surface 22a can be effectively protected by the substrate 21. Thus, the reliability of the mirror device 20 can be improved. Additionally, "the first surface 21a of the substrate 21 is positioned further to one side than the mirror surface 22a" means that "at least a portion of the first surface 21a is positioned further to one side than the mirror surface 22a." In the mirror device 20, the entire first surface 21a is positioned further to one side than the mirror surface 22a in the Z-axis direction. In other words, the entire reflective mirror 22a is located on the opposite side of the first surface 21a in the Z-axis direction. "The surface on one side of the substrate in the Z-axis direction" is in other words "the end face on one side of the substrate in the Z-axis direction" or "the surface of the substrate located at the edge of one side in the Z-axis direction".

[0141] One end face (end face 224as, 224bs, 224cs) of the beam portion 224 in the Z-axis direction is located on the side closer to the reflector surface 22a. Therefore, the other beam portion 224 can also protect the reflector surface 22a. Furthermore, the beam portion 224 can also suppress deformation during the movement of the movable portion 22b.

[0142] The beam portion 224 has an inner beam portion 224a disposed on one side of the surface of the placement portion 221, extending along the outer edge of the placement portion 221 when viewed from the Z-axis direction. Therefore, the inner beam portion 224a is disposed near the reflector surface 22a, thereby more effectively protecting the reflector surface 22a. Furthermore, since the inner beam portion 224a is disposed on the placement portion 221, deformation of the placement portion 221 can be more appropriately suppressed.

[0143] The beam portion 224 has an outer beam portion 224b disposed on one side of the surface of the frame portion 222 in such a manner that it extends along the frame portion 222 when viewed from the Z-axis direction. Therefore, the beam portion 224 can more effectively protect the reflector surface 22a. Furthermore, the outer beam portion 224b can suppress deformation of the frame portion 222, thereby suppressing deformation of the configuration portion 221 caused by deformation of the frame portion 222.

[0144] The support layer 101 constituting the beam portion 224 is thinner than the support layer 101 constituting the base 21. As a result, it is possible to suppress the protrusion of the beam portion 224 from the base 21 during the movement of the movable portion 22b in this situation, and to increase the amount of movement of the movable portion 22b in the Z-axis direction.

[0145] On the substrate 21, a groove 216 is formed from the surface 101a (one side surface in the Z-axis direction) of the support layer 101 to the device layer 102, extending in a manner that surrounds the opening 213 when viewed from the Z-axis direction. As a result, the groove 216 can be used to achieve electrical insulation of the electrode pad 211, thereby further improving reliability.

[0146] The electrode pad 211 extends across the bottom surface 214 and side surface 215 of the opening 213. This allows for a large-area electrode pad 211. The metal layer constituting the electrode pad 211 is thicker than the metal layer constituting the reflector surface 22a. In this case, deformation of the reflector surface 22a can be suppressed, and electrical connection of the ground electrode pad 211 can be achieved. That is, to suppress warping of the reflector surface 22a, it is preferable that the metal layer constituting the reflector surface 22a is thinner. By making the metal layer constituting the electrode pad 211 thicker, wire bonding performance in the wire bonding process can be improved. If the electrode pad 211 is too thin, there is a concern that the cable cannot be placed properly or that sufficient adhesion cannot be obtained; such a situation can be suppressed in the reflector device 20.

[0147] In the mirror unit 2, the light transmission section 14 of the optical functional component 13 can correct the difference in optical path length between the beam splitter unit 3 and the movable mirror 22, and between the beam splitter unit 3 and the fixed mirror 16. "Correcting the difference in optical path length" means reducing the difference between the optical path length (considering the refractive index of each medium through which the optical path passes) between the beam splitter unit 3 and the movable mirror 33, and the optical path length between the beam splitter unit 3 and the fixed mirror 16. Furthermore, in the mirror unit 2, for example, compared to a structure where "the mirror surface 22a is disposed on the surface of the device layer 102 opposite to the intermediate layer 103, and the substrate 21 is joined to the third surface 13a of the optical functional component 13 on the surface of the support layer 101 opposite to the intermediate layer 103," the mirror surface 22a is disposed near the optical functional component 13. Such a structure is particularly effective when using the light transmission section 14 to correct the difference in optical path length. That is, for example, the reference position of the movable mirror 22, which reciprocates along the Z-axis, can be easily (with minimal movement) positioned on the third surface 13a of the optical functional component 13. Therefore, the amount of reciprocating movement of the movable mirror 22 along the Z-axis can be suppressed, and a sufficient optical interference signal can be obtained.

[0148] [Variation Example]

[0149] In the above embodiments, the materials and shapes of each structure are not limited to those described above, and various materials and shapes can be used. For example, the arrangement part 221 and the reflective mirror surface 22a can each be any shape, such as rectangular or octagonal, when viewed from the Z-axis direction. The frame part 222 can also be any ring shape, such as rectangular ring or octagonal ring, when viewed from the Z-axis direction. The light-passing opening 24 and the light-passing opening 25 can each be any shape, such as circular with an octagonal shape, when viewed from the Z-axis direction. The reflective mirror device 20 can also have a hole or cut formed in the substrate 21 as the first light-passing part instead of the light-passing opening 24 or the light-passing part 25. The semiconductor substrate constituting the reflective mirror device 20 does not necessarily have to be an SOI substrate; any substrate that has a first semiconductor layer, an insulating layer, and a second semiconductor layer sequentially from one side in the Z-axis direction is acceptable.

[0150] The inner beam portion 224a, the outer beam portion 224b, and the connecting beam portion 224c can each be formed in any shape. For example, the beam portions can extend obliquely or in a zigzag pattern relative to the X-axis or Y-axis direction. The arrangement, number, length, width, and thickness of each beam portion can be arbitrarily set. For example, the thicknesses of the inner beam portion 224a, the outer beam portion 224b, and the connecting beam portion 224c can be different from each other. At least one of these beam portions can also be omitted. The beam portion 224 can also not surround the reflective mirror surface 22a when viewed from the Z-axis direction. The thickness of the support layer 101 constituting the beam portion 224 can also be the same as the thickness of the support layer 101 constituting the substrate 21. The shapes of the first torsion bars 266, 276 and the second torsion bars 267, 277 are not limited and can be any shape such as a rod. The electrode pad 211 can also be disposed only on the bottom surface 214 of the opening 213 and not reach the side surface 215. In this case, the groove 216 can also be omitted. The second surface 21b of the substrate 21 and the third surface 13a of the optical functional component 13 can also be bonded to each other by means other than direct bonding (e.g., adhesives such as UV-curable resins). The fixed mirror 16 can be disposed on the opposite side of the mirror device 20 relative to the optical functional component 13, or it can be disposed away from the fourth surface 13b of the optical functional component 13.

[0151] The optical device of the present invention is not limited to a mirror device; other optical functional parts besides the mirror surface 22a can also be optical devices disposed on the movable part 22b. Examples of other optical functional parts include lenses. The driving part 23 of the mirror device 20 may also have three or more elastic support parts that elastically support the movable mirror 22. The actuator part 28 is not limited to an electrostatic actuator; for example, it can be a piezoelectric actuator, an electromagnetic actuator, etc. In the above embodiment, the moving direction (prescribed direction) of the movable part 22b is perpendicular to the first surface 21a of the substrate 21, but the moving direction can be any direction intersecting the first surface 21a. The mirror device 20 is not limited to a mirror device constituting FTIR; it can also be a mirror device constituting other optical systems. The structures in one embodiment or variation described above can be arbitrarily applied to structures in other embodiments or variations.

[0152] Explanation of reference numerals in the attached figures

[0153] 3…beam splitter unit

[0154] 13…Optical functional components

[0155] 14…Light transmission section (second light transmission section)

[0156] 16… Fixed reflector

[0157] 20…Reflective mirror devices (optical devices)

[0158] 21…matrix

[0159] 21a… First surface (main face)

[0160] 21b…Second surface (main face)

[0161] 22a…Reflective mirror (optical functional part)

[0162] 22b…Articulated Part

[0163] 221… Configuration Department

[0164] 222… Frame

[0165] 223…Connection Section

[0166] 224…Beam section

[0167] 24… Light passes through the opening (first light-passing section)

[0168] 100…SOI substrate (semiconductor substrate)

[0169] 101… Support layer (first semiconductor layer)

[0170] 101a…Surface

[0171] 102… Device layer (second semiconductor layer)

[0172] 102a… Surface

[0173] 103…Intermediate layer (insulating layer)

[0174] 211…Electrode pad

[0175] 213…opening

[0176] 214…Bottom

[0177] 215…side view

[0178] 216…groove section.

Claims

1. An optical device, characterized in that, include: A substrate with a main surface; The movable part is supported on the base in such a way that it can move along a predetermined direction intersecting the main surface; and An optical functional unit disposed on the movable part. The substrate and the movable part are composed of a semiconductor substrate having a first semiconductor layer, an insulating layer and a second semiconductor layer sequentially from one side of the predetermined direction. The substrate is composed of the first semiconductor layer, the insulating layer, and the second semiconductor layer. The movable part has a configuration section formed by the second semiconductor layer. The optical functional unit is disposed on the surface of one side of the configuration unit. The first semiconductor layer constituting the substrate is thicker than the second semiconductor layer constituting the substrate. The surface of the substrate on one side is located on a side closer to the optical functional part than the optical functional part. The optical device also has an electrode pad disposed on the substrate. The electrode pad is disposed on the surface of the second semiconductor layer within an opening formed on the surface of the first semiconductor layer on one side, such that it reaches the second semiconductor layer. The substrate has a groove formed on the surface of one side of the first semiconductor layer in such a way that it reaches the second semiconductor layer and extends in such a way that it surrounds the opening when viewed from the predetermined direction.

2. The optical device as described in claim 1, characterized in that: The electrode pad extends across the bottom and sides of the opening.

3. The optical device as described in claim 1 or 2, characterized in that: The electrode pad and the optical functional part are each composed of a metal layer. The metal layer constituting the electrode pad is thicker than the metal layer constituting the optical functional part.

4. The optical device as described in claim 1, characterized in that: The movable part further includes a frame portion that surrounds the configuration part when viewed from the predetermined direction and a connecting portion that connects the configuration part to the frame portion.

5. The optical device as described in claim 4, characterized in that: The frame portion and the connecting portion are formed by the second semiconductor layer.

6. A reflector unit, characterized in that, include: The optical device according to any one of claims 1 to 5; An optical functional component disposed on the opposite side of the specified direction relative to the optical device; and The fixed reflector, which is positioned on the other side relative to the optical functional components, The optical functional part, together with the movable part, constitutes the reflective surface of the movable reflector. The optical device has a first light-passing portion forming a first part of the optical path between the beam splitter unit and the fixed mirror, wherein the beam splitter unit, together with the movable mirror and the fixed mirror, constitutes an interference optical system. The optical functional component has a second light-passing portion that forms the second part of the optical path between the beam splitter unit and the fixed reflector. The second light transmission section corrects the optical path difference generated between the optical path between the beam splitter unit and the movable mirror and between the optical path between the beam splitter unit and the fixed mirror.

Images