JP5888002B2 - Wavelength variable interference filter, optical filter device, optical module, and electronic apparatus - Google Patents

Description

  The present invention relates to a wavelength tunable interference filter, an optical filter device, an optical module, and an electronic apparatus.

2. Description of the Related Art Conventionally, there has been known a wavelength variable interference filter in which reflection films are arranged on opposite surfaces of a pair of substrates with a predetermined gap therebetween (see, for example, Patent Document 1).
The wavelength λ of light extracted by such a tunable interference filter is such that the distance between the reflection films is d, the refractive index of the medium between the reflection films is n (in the case of air, n = 1), and the light incident angle is θ. , M satisfies the order shown in the following formula (1).

[Equation 1]
mλ = 2nd cos θ (1)

  As shown in the equation (1), the spectral characteristic of the wavelength variable interference filter has a plurality of peak wavelengths having different orders m. Therefore, when light having a wide wavelength band is incident on the wavelength variable interference filter, light corresponding to a plurality of peak wavelengths is transmitted, which is inconvenient when it is desired to extract only light having a specific peak wavelength.

On the other hand, an apparatus for extracting a predetermined peak wavelength from the wavelength variable interference filter as described above is known (for example, see Patent Document 1).
In the optical filter of Patent Document 1, movable substrates are bonded to both sides of a fixed substrate, and each substrate is provided with a reflective film in a region overlapping each other in a plan view when the substrates are viewed from the thickness direction. Here, the reflective film of the fixed substrate is provided on a surface facing one of the movable substrates, and a first Fabry-Perot etalon element is configured with the reflective film provided on the movable substrate. Further, the reflective film of the fixed substrate is opposed to the reflective film provided on the other movable pair substrate via the fixed substrate itself, and the second Fabry-Perot etalon element is interposed between the reflective film and the reflective film. Composed.
The optical filter has a configuration in which a predetermined transmission wavelength is selected from a plurality of peak wavelengths by advancing and retreating a movable portion provided with a reflective film on the movable substrate with respect to the fixed substrate.

Japanese Patent Laying-Open No. 2005-31326

  By the way, in the above-mentioned Patent Document 1, in the second Fabry-Perot etalon element, the fixed substrate is interposed between the reflective film of the fixed substrate and the reflective film of the movable substrate. In such a configuration, there is a problem that the range in which the distance between the reflective films can be changed is narrowed by the thickness dimension of the fixed substrate, and the wavelengths that can be selected by the optical filter are limited.

  An object of the present invention is to provide a variable wavelength interference filter, an optical filter device, an optical module, and an electronic apparatus that can extract a specific wavelength from light in a wide wavelength band.

The wavelength tunable interference filter of the present invention includes a first substrate, a second substrate disposed to face the first substrate, and a first reflection provided on a surface of the first substrate facing the second substrate. A second reflective film provided on a surface of the second substrate facing the first substrate and facing the first reflective film via a gap between the first reflective films; and the first reflective film. A first actuator that changes a gap between the first substrate, a third substrate disposed opposite to a surface opposite to the surface facing the second substrate of the first substrate, and the third substrate of the first substrate A third reflective film provided on the facing surface and a third reflective film provided on a surface of the third substrate facing the first substrate, facing the third reflective film via a second inter-reflective film gap. Four reflective films, and a second actuator that changes the gap between the second reflective films, In the plan view of the first substrate, the second substrate, and the third substrate viewed from the substrate thickness direction, the first reflective film, the second reflective film, the third reflective film, and the first four reflective film, Ri least some heavy Do each other, said first actuator, a voltage is applied, the first reflecting film between changing the gap, the second actuator, a voltage is applied, the second reflecting film An inter-gap is changed, and in the plan view, at least one of the first substrate and the second substrate includes a first protrusion that protrudes outward from the outer peripheral edge of the other, and the first protrusion Is provided with a first terminal for applying a voltage to the first actuator, and in the plan view, at least one of the first substrate and the third substrate protrudes more outward than the other peripheral edge. It includes a projecting portion, wherein the second protruding portion, wherein the second terminal unit for applying a voltage to the second actuator is provided.
The wavelength tunable interference filter according to the present invention includes a first substrate, a second substrate disposed to face the first substrate, and a first substrate provided on a surface of the first substrate facing the second substrate. A second reflective film provided on a surface of the second substrate facing the first substrate and facing the first reflective film via a gap between the first reflective films; A first actuator for changing a gap between the reflective films; a third substrate disposed opposite to a surface of the first substrate opposite to the surface facing the second substrate; and the third substrate of the first substrate. A third reflective film provided on a surface facing the substrate and a surface of the third substrate facing the first substrate, and facing the third reflective film via a gap between the second reflective films And a second actuator for changing the gap between the second reflective films In the plan view of the first substrate, the second substrate, and the third substrate viewed from the substrate thickness direction, the first reflective film, the second reflective film, the third reflective film, and the fourth reflecting film, Ri least some heavy Do each other, a first terminal protrusion protruding outward from the outer peripheral edge of a portion of the first substrate is the second substrate, the second substrate- A second terminal protrusion that protrudes outward from the outer periphery of the first substrate; a third terminal protrusion that protrudes outward from the outer periphery of the third substrate; A portion of the third substrate that protrudes outward from the outer peripheral edge of the first substrate, and the first actuator is a surface of the first substrate that faces the second substrate. A first electrode provided on the second substrate, and a predetermined gap on the first electrode And the second actuator is provided on a surface of the first substrate facing the third substrate, and is provided on the third substrate, and the third electrode has a predetermined value on the third electrode. A first electrode connected to the first electrode is provided on the first terminal protrusion, and the second terminal protrusion is provided with the second electrode. A second terminal connected to the electrode is provided, the third terminal protruding portion is provided with a third terminal connected to the third electrode, and the fourth terminal protruding portion is provided with the fourth electrode. A fourth terminal to be connected is provided.

In the present invention, the second substrate is provided on one side of the first substrate, and the third substrate is provided on the other side. The first substrate and the second substrate are respectively provided with a first reflecting film and a second reflecting film that face each other, and the gap amount of the gap between the first reflecting films can be changed by the first actuator. Has been. Further, the first substrate and the third substrate are provided with a third reflecting film and a fourth reflecting film, respectively, facing each other, and the gap amount of the gap between the second reflecting films can be changed by the second actuator. Has been.
In the wavelength tunable interference filter having such a configuration, the gap amounts in the first inter-reflective film gap and the second inter-reflective film gap are set to different values, and a plurality of values extracted by the first reflective film and the second reflective film are used. Each gap amount is set so as to overlap one of the peak wavelengths with one of the plurality of peak wavelengths extracted by the third reflection film and the fourth reflection film. Thereby, the light corresponding to the peak wavelength which overlapped among the light of a plurality of peak wavelengths can be taken out.

Here, in a configuration in which a substrate or the like is interposed in either the first inter-reflection film gap or the second inter-reflection film gap, the changeable range of the inter-reflection film gap is small. For example, when a substrate or the like is interposed in the gap between the second reflection films, the settable range becomes small as the gap amount of the gap between the second reflection films. For this reason, the wavelength range that can be superimposed on one of the peak wavelengths of the light extracted by the first reflective film and the second reflective film is also reduced, and as a result, it can be extracted by the wavelength variable interference filter. The wavelength range is narrowed.
On the other hand, in the present invention, the first reflecting film gap and the second reflecting film gap do not include any members constituting the substrate, and the gap range of the reflecting film gap can be changed. Can be big. Thereby, even when light in a wide wavelength band is incident on the wavelength variable interference filter, light having a desired specific wavelength can be extracted.

In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the first substrate, the second substrate, and the third substrate have translucency with respect to visible light.
In the present invention, since the first substrate, the second substrate, and the third substrate have translucency with respect to visible light, the wavelength region that can be extracted by the wavelength variable interference filter is from the visible light region to the near infrared region. A wide wavelength range can be covered.

In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the first substrate, the second substrate, and the third substrate are a quartz substrate or a glass substrate.
In the present invention, since the first substrate, the second substrate, and the third substrate are quartz substrates or glass substrates, the substrate shape can be easily processed by processing such as wet etching.

  In the wavelength tunable interference filter according to the aspect of the invention, the second substrate includes a first movable portion, and a first holding portion provided around the first movable portion in the plan view, and the second reflective film. Is preferably provided in the first movable part.

  In the present invention, since the first movable part is configured to be held by the first holding part, the first movable part can be easily moved forward and backward with respect to the first substrate by bending the first holding part. Become. Moreover, since the bending of the first movable part when the first holding part is bent can be suppressed, the distortion of the second reflective film provided on the first movable part can also be suppressed, and the resolution of the wavelength variable interference filter can be improved. Can do.

  In the variable wavelength interference filter according to the aspect of the invention, the third substrate includes a second movable portion and a second holding portion provided around the second movable portion in the plan view, and the fourth reflective film. Is preferably provided in the second movable part.

  In the present invention, since the second movable part is configured to be held by the second holding part, the second movable part can be easily moved forward and backward with respect to the first substrate by bending the second holding part. Become. Moreover, since the bending of the second movable part when the second holding part is bent can be suppressed, the distortion of the fourth reflective film provided in the second movable part can also be suppressed, and the resolution of the wavelength variable interference filter can be improved. Can do.

In the wavelength tunable interference filter according to the aspect of the invention, the first actuator may change the gap between the first reflection films by applying a voltage, and the second actuator may change the gap between the second reflection films by applying a voltage. in the plan view, the at least one of the first substrate and the second substrate includes a first protrusion protruding outward from the other of the outer peripheral edge, said first projection, the first the first terminal portion is provided for applying a voltage to the actuator, in the plan view, the first substrate and at least one of the third substrate, the second protrusion protruding outward from the other of the outer peripheral edge provided, wherein the second protruding portion, wherein the second terminal unit for applying a voltage to the second actuator is provided.

In the present invention, at least one of the first substrate and the second substrate protrudes outward from the outer peripheral edge of the other substrate, and a first terminal portion for applying a voltage to the first actuator is provided. Configure the protrusion. Similarly, at least one of the first substrate and the third substrate protrudes outside the outer peripheral edge of the other substrate, and a second protrusion is provided with a second terminal portion for applying a voltage to the second actuator. Parts.
In such a configuration, even when three substrates are bonded, the first terminal portion and the second terminal portion protrude outward, so that it is easy to provide wiring for voltage application, and at the time of wiring Work efficiency can be improved.

  In the wavelength tunable interference filter according to the aspect of the invention, the first actuator may include a first electrode provided on a surface of the first substrate facing the second substrate, a second electrode provided on the second substrate, and the first electrode provided on the first electrode. A second electrode facing the gap through the gap, and the second actuator is provided on a surface of the first substrate facing the third substrate, provided on the third substrate, A fourth electrode opposed to the third electrode via a predetermined gap, and in the plan view, at least one of the first substrate and the second substrate protrudes outward from the outer peripheral edge of the other. The first protrusion is provided with a first terminal connected to the first electrode and a second terminal connected to the second electrode, and in the plan view, Small number of first and third substrates At least one of the two includes a second protrusion that protrudes outward from the outer peripheral edge of the other, and the second protrusion includes a third terminal connected to the third electrode, and a fourth electrode. It is preferable that a fourth terminal to be connected is provided.

In the present invention, at least one of the first substrate and the second substrate protrudes outward from the outer peripheral edge of the other substrate to constitute the first protrusion. The first actuator is an electrostatic actuator composed of a first electrode and a second electrode, and a first terminal connected to the first electrode and a second terminal connected to the second electrode are respectively Provided on the first protrusion. Similarly, at least one of the first substrate and the third substrate protrudes outward from the outer peripheral edge of the other substrate to form a second protrusion. And the 2nd actuator is an electrostatic actuator comprised by the 3rd electrode and the 4th electrode, and the 3rd terminal connected to the 3rd electrode and the 4th terminal connected to the 4th electrode, respectively, Provided on the second protrusion.
In such a configuration, even when three substrates are bonded, the first terminal portion and the second terminal portion protrude outward. The part may be provided with a first terminal, a second terminal, a third terminal, and a fourth terminal connected to the first and second electrostatic actuators. As a result, each terminal is exposed to the outer surface of the wavelength tunable interference filter, and it is easy to provide wiring for applying a voltage to each actuator, and work efficiency during wiring can be improved.
Moreover, in this invention, a 1st terminal and a 2nd terminal will be provided in the same 1st terminal part. Therefore, for example, by connecting an FPC (Flexible printed circuits) having a connection portion for the first terminal and the second terminal to the first projecting portion, it is possible to simultaneously connect to these terminals. Thereby, the work efficiency at the time of wiring can be improved more compared with the structure etc. in which a 1st terminal and a 2nd terminal are provided in a different protrusion part, for example. The same applies to the third terminal and the fourth terminal. By providing both the third terminal and the fourth terminal in the second projecting portion, the work efficiency during wiring can be further improved.

In the wavelength tunable interference filter according to the aspect of the invention, a part of the first substrate protrudes outward from an outer peripheral edge of the second substrate, and a part of the second substrate is a part of the first substrate. A second terminal protruding portion that protrudes outward from the outer peripheral edge, a third terminal protruding portion in which a portion of the first substrate protrudes outward from the outer peripheral edge of the third substrate, and a portion of the third substrate A fourth terminal projecting portion projecting outward from the outer peripheral edge of the first substrate, and the first actuator is a first electrode provided on a surface of the first substrate facing the second substrate; A second electrode provided on the second substrate and facing the first electrode via a predetermined gap, and the second actuator is provided on a surface of the first substrate facing the third substrate. A third electrode provided on the third substrate, and the third electrode A first electrode connected to the first electrode is provided on the first terminal protrusion, and the second electrode is provided on the second terminal protrusion. A third terminal connected to the third electrode is provided on the third terminal protrusion, and a fourth terminal is connected to the fourth electrode on the fourth terminal protrusion. wherein the fourth terminal is provided that is.

In the present invention, the first actuator is composed of a first electrode and a second electrode facing each other, and changes the gap amount of the gap between the first reflective films by applying an electrostatic attractive force between the electrodes by applying a voltage. Similarly, the second actuator is also composed of a third electrode and a fourth electrode facing each other.
In such a configuration, for example, the number of members can be reduced as compared with a configuration using a piezoelectric element or the like, and the gap amount can be adjusted with high accuracy by applying a voltage.
The wavelength tunable interference filter includes a first terminal protruding portion in which a part of the first substrate protrudes from the outer peripheral edge of the second substrate, the first terminal connected to the first electrode, and the second substrate. Is provided so as to protrude from the outer peripheral edge of the first substrate, and includes a second terminal protruding portion provided with a second terminal connected to the second electrode. In such a configuration, the first terminal is drawn out to the first terminal protrusion of the first substrate on which the first electrode is provided, and the second terminal is the second terminal protrusion of the second substrate on which the second electrode is provided. Pulled out. For this reason, for example, compared with the case where the lead wire of the second electrode is pulled out to the terminal provided in the first terminal protrusion of the first substrate through a separate conductive member, each substrate configuration can be simplified, and The work efficiency during wiring can be improved.
The same applies to the third electrode and the fourth electrode constituting the second actuator, and the third electrode and the fourth electrode are respectively provided on the third terminal protruding portion and the third terminal protruding portion. By pulling out to the fourth terminal provided in the circuit board, the configuration of each board can be simplified, and the efficiency of wiring work can be improved.

  In the wavelength tunable interference filter according to the aspect of the invention, in the plan view, the first substrate, the second substrate, and the third substrate have rectangular substrate overlapping portions that overlap each other, and the first terminal protrusions The second terminal protruding portion, the third terminal protruding portion, and the fourth terminal protruding portion protrude from different sides of the substrate overlapping portion in different directions, and the second substrate overlaps the substrate overlapping portion. Projecting from the portion in the same direction as the projecting direction of the third terminal projecting portion and by the same dimension, the third substrate from the substrate overlapping portion in the same direction as the projecting direction of the first terminal projecting portion, and It is preferable to protrude by the same dimension.

As described above, when the first terminal protrusion, the second terminal protrusion, the third terminal protrusion, and the fourth terminal protrusion are provided, for example, the first substrate, the second substrate, and the third substrate are set to the substrate thickness. In the plan view seen from the direction, it is conceivable to provide each terminal portion by arranging these substrates in a staircase pattern along a predetermined direction. However, with such a substrate arrangement, the production efficiency deteriorates.
That is, when manufacturing a wavelength tunable interference filter, each wavelength tunable interference filter is manufactured by cutting a plurality of wavelength tunable interference filters arranged in parallel on one wafer, and finally cutting each chip. It is preferable. However, as described above, when the substrates are arranged in a staircase pattern, it is necessary to cut the first substrate, the second substrate, and the third substrate along different lines, respectively. It becomes difficult to cut the first substrate to be sandwiched.

  On the other hand, in the present invention, the first terminal projecting portion, the second terminal projecting portion, the third terminal projecting portion, and the fourth terminal projecting portion are each provided on each side of the rectangular substrate overlapping portion, Each is provided so as to protrude in a direction away from the substrate overlapping portion (a direction different from each other). The second board protrudes by the same dimension in the same direction as the third terminal protrusion, and the third board has a shape protruding by the same dimension in the same direction as the first terminal protrusion. In such a configuration, the protruding tip line of the third terminal protruding portion of the first substrate and the outer peripheral line of the second substrate are the same, and can be cut along the same cutting line. Similarly, the line at the protruding tip of the third terminal protruding portion of the first substrate and the line at the outer peripheral edge of the third substrate are the same, and can be cut along the same line. Thereby, after joining a 1st board | substrate, a 2nd board | substrate, and a 3rd board | substrate, a 1st board | substrate can be easily cut | disconnected and manufacturing efficiency can be improved.

  The wavelength tunable interference filter of the present invention includes a substrate, a first reflection film, a second reflection film facing the first reflection film via a first reflection film gap, and the first reflection film gap. A first Fabry-Perot variable etalon including a first actuator to be changed, a third reflective film, a fourth reflective film facing the third reflective film via a gap between the second reflective films, and the second reflective film A second Fabry-Perot variable etalon including a second actuator that changes a gap between the first Fabry-Perot variable etalon and the second Fabry-Perot variable etalon, and the second Fabry-Perot variable etalon is disposed on both sides of the substrate. The first reflective film is disposed on one surface of the substrate, the third reflective film is disposed on the other surface of the substrate, and the substrate is viewed from the thickness direction of the substrate. In plan view, the first reflecting film, the second reflecting film, the third reflective layer, and the fourth reflective film is characterized in that at least partially overlap each other.

In the present invention, the first Fabry-Perot variable etalon is provided on one side of the substrate, and the second Fabry-Perot variable etalon is provided on the other side of the substrate. In the wavelength tunable interference filter having such a configuration, the gap amounts in the first reflective film gap and the second reflective film gap are set to different values as in the above invention, and the first reflective film and the second reflective film are set. Each gap amount is set so as to overlap one of the plurality of peak wavelengths extracted by the film with one of the plurality of peak wavelengths extracted by the third reflection film and the fourth reflection film. Thereby, the light corresponding to the peak wavelength which overlapped among the light of a plurality of peak wavelengths can be taken out.
In the present invention, the first reflective film is provided on one surface of the substrate, and the third reflective film is provided on the other surface. In other words, since the substrate is not interposed in the gap between the first reflective films of the first Fabry-Perot variable etalon nor in the gap between the second reflective films of the second Fabry-Perot variable etalon, The changeable range of the gap amount can be increased. Thereby, even when light in a wide wavelength band is incident on the wavelength variable interference filter, light having a desired specific wavelength can be extracted.

An optical filter device according to the present invention includes the above-described variable wavelength interference filter and a housing that houses the variable wavelength interference filter .

  In the optical filter device of the present invention, similarly to the above-described invention, in the wavelength variable interference filter, light having a desired peak wavelength can be extracted over a wide wavelength band. In addition, since the wavelength tunable interference filter is housed in the housing, it is possible to suppress the entry of foreign substances such as charged substances and water particles. Thereby, the fluctuation | variation of the gap between 1st reflective films by the adhesion of the charged substance to a reflective film and the gap between 2nd reflective films, and deterioration of each reflective film can be prevented. In addition, the wavelength tunable interference filter can be protected during transportation, and the work efficiency when the wavelength tunable interference filter is incorporated into equipment can be improved.

An optical module of the present invention includes the above-described wavelength variable interference filter and a detection unit that detects light, and the first substrate, the second substrate, and the third substrate are viewed from the substrate thickness direction. in the plan view, the first reflecting film, the second reflecting film, the third reflective layer, and the optical interference region is constituted by the fourth reflecting film are overlapped area, the detection unit, the optical interference region The light extracted by the step is detected.

  In the present invention, it is possible to extract light having a desired peak wavelength by adjusting the gap amounts of the first reflective film gap and the second reflective film gap even for measurement target light having a wide wavelength band. . Therefore, the light of the specific peak wavelength can be detected by the detection unit. Therefore, it is possible to accurately detect the amount of light of a desired specific wavelength from the measurement target light having a wide wavelength band.

An electronic apparatus according to the present invention includes the above-described wavelength variable interference filter, and a control unit that controls the first actuator and the second actuator.

  In the present invention, it is possible to extract light having a desired peak wavelength by adjusting the gap amounts of the first reflective film gap and the second reflective film gap even for measurement target light having a wide wavelength band. . Therefore, even in electronic equipment, for example, when light of a wavelength extracted between these reflective films is detected and various processing is performed based on the detected light, light of a wavelength other than a specific wavelength is mixed. Without being able to perform accurate processing.

  In the electronic device according to the aspect of the invention, the control unit may set the gap between the second reflection films to a value different from the gap between the first reflection films and the first reflection within a predetermined measurement target wavelength range. One of a plurality of peak wavelengths extracted by the film and the second reflective film overlaps one of a plurality of peak wavelengths extracted by the third reflective film and the fourth reflective film. It is preferable to set the gap between one reflective film and the gap between the second reflective films.

In the present invention, the control unit sets the gap amounts of the first reflective film gap and the second reflective film gap to different values. Then, the control unit, in the measurement target wavelength range, one of the peak wavelengths of the light extracted by the first reflective film and the second reflective film, and the peak wavelength of the light extracted by the third reflective film and the fourth reflective film The gap amount is adjusted so that one of the two overlaps.
Thereby, except for a specific peak wavelength, the positions of the peak wavelengths of light extracted by the first reflective film and the second reflective film and the positions of the peak wavelengths of light extracted by the third reflective film and the fourth reflective film are shifted. Thus, only light having a specific peak wavelength can be extracted.

1 is a block diagram showing a schematic configuration of a spectrometer according to a first embodiment of the present invention. The top view which shows schematic structure of the wavelength variable interference filter of 1st embodiment. FIG. 3 is a cross-sectional view of the variable wavelength interference filter of FIG. 2 taken along line III-III. (A) The top view which looked at the 1st board | substrate of 1st embodiment from the 2nd board | substrate side. (B) The top view which looked at the 1st substrate of the first embodiment from the 3rd substrate side. The top view which looked at the 2nd substrate of the first embodiment from the 1st substrate side. The top view which looked at the 3rd board | substrate of 1st embodiment from the 1st board | substrate side. The figure which shows an example of the transmission characteristic of a wavelength variable interference filter. The figure which shows the manufacturing process of the 1st board | substrate of 1st embodiment. The figure which shows the manufacturing process of the 2nd board | substrate of 1st embodiment. The figure which shows the chip | tip manufacturing process in manufacture of the wavelength variable interference filter of 1st embodiment. The top view which shows schematic structure of the wavelength variable interference filter of 2nd embodiment. FIG. 12 is a cross-sectional view of the tunable interference filter of FIG. 11 taken along line AA. FIG. 12 is a cross-sectional view of the wavelength tunable interference filter of FIG. The figure which shows the chip | tip manufacturing process in manufacture of the wavelength tunable filter of 2nd embodiment. Sectional drawing which shows schematic structure of the optical filter device of 3rd embodiment. Schematic which shows the gas detection apparatus (electronic device) provided with the wavelength variable interference filter of this invention. The block diagram which shows the structure of the control system of the gas detection apparatus of FIG. The figure which shows schematic structure of the food-analysis apparatus (electronic device) provided with the wavelength variable interference filter of this invention. The figure which shows schematic structure of the spectroscopic camera (electronic device) provided with the wavelength variable interference filter of this invention.

[First embodiment]
Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings.
[Configuration of Spectrometer]
FIG. 1 is a block diagram showing a schematic configuration of a spectrometer according to the present invention.
The spectroscopic measurement device 1 is a device that analyzes the light intensity of each wavelength in the measurement target light reflected by the measurement target X, for example, and measures the spectral spectrum. In this embodiment, an example of measuring the measurement target light reflected by the measurement target X is shown. However, when a light emitter such as a liquid crystal panel is used as the measurement target X, the light emitted from the light emitter is measured. The target light may be used.
As shown in FIG. 1, the spectroscopic measurement apparatus 1 includes an optical module 10 and a control circuit unit 20 that processes a signal output from the optical module 10.

[Configuration of optical module]
The optical module 10 includes a variable wavelength interference filter 5, a detection unit 11, an IV converter 12, an amplifier 13, an A / D converter 14, and a voltage control unit 15.
The optical module 10 guides the measurement target light reflected by the measurement target X to the wavelength variable interference filter 5 through an incident optical system (not shown), and receives the light transmitted through the wavelength variable interference filter 5 by the detection unit 11. To do. The detection signal output from the detection unit 11 is output to the control circuit unit 20 via the IV converter 12, the amplifier 13, and the A / D converter 14.

[Configuration of wavelength tunable interference filter]
Next, a variable wavelength interference filter incorporated in the optical module will be described.
FIG. 2 is a plan view showing a schematic configuration of the variable wavelength interference filter 5. 3 is a cross-sectional view of FIG. 2 taken along the line III-III.
As shown in FIGS. 2 and 3, the variable wavelength interference filter 5 includes a first substrate 51 (a substrate in the present invention), a second substrate 52, and a third substrate 53. Each of these substrates 51, 52, and 53 is formed of, for example, various glasses such as soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass, crystal, and the like. . The first substrate 51 and the second substrate 52 are bonded by a bonding film 54A (see FIG. 3), and the first substrate and the third substrate 53 are bonded by a bonding film 54B (see FIG. 3). As the bonding films 54A and 54B, for example, a plasma polymerized film mainly containing siloxane can be used.

A first reflective film 551 is provided on the surface of the first substrate 51 facing the second substrate 52, and a second reflective film 552 is provided on the surface of the second substrate 52 facing the first substrate 51. The first reflective film 551 and the second reflective film 552 are disposed to face each other through a first inter-reflective film gap (hereinafter, sometimes abbreviated as a first gap) G1.
Further, the variable wavelength interference filter 5, a first reflective layer 551 and the first gap G1 electrostatic actuator 56A which is used to adjust the gap amount g ₁ between the second reflective film 552 (first actuator) is Is provided. The electrostatic actuator 56A includes a first electrode 561 provided on the first substrate 51 side and a second electrode 562 provided on the second substrate 52 side.
Therefore, the first reflective film 551, the second reflective film 552, and the electrostatic actuator 56A constitute the first Fabry-Perot variable etalon of the present invention.

Further, a third reflective film 553 is provided on the surface of the variable wavelength interference filter 5 that faces the third substrate 53 of the first substrate 51, and the fourth reflection is provided on the surface of the third substrate 53 that faces the first substrate 51. A membrane 554 is provided. The third reflective film 553 and the fourth reflective film 554 are disposed to face each other via a second inter-reflective film gap (hereinafter may be abbreviated as a second gap) G2. Here, the second gap G2, the third reflective layer 553 and the fourth reflective layer 554 is opposed with a gap weight _{g 2.}
Further, the variable wavelength interference filter 5, a third reflective layer 553 and the second gap G2 of the electrostatic actuator 56B used to adjust the gap distance g ₂ between the fourth reflecting film 554 (second actuator) is Is provided. The electrostatic actuator 56B includes a third electrode 563 provided on the first substrate 51 side and a fourth electrode 564 provided on the third substrate 53 side.
Therefore, the second Fabry-Perot variable etalon of the present invention is configured by the third reflective film 553, the fourth reflective film 554, and the electrostatic actuator 56B.

  The first reflective film 551 and the second reflective film 552 are seen in a plan view (filter plan view) when the variable wavelength interference filter 5 is viewed from the thickness direction of the first substrate 51, the second substrate 52, and the third substrate 53. The third reflection film 553 and the fourth reflection film 554 overlap each other, and the overlapping region constitutes a light interference region Ar0.

Further, in the filter plan view, the center points of the reflection films 551, 552, 553, and 554 coincide with each other, and the center point coincides with the center point of the movable portion 521 described later, and the first substrate 51 and the second substrate 51 The substrate 52 and the third substrate 53 coincide with the center point of the substrate overlap portion 555 where the substrate 52 and the third substrate 53 overlap each other (a region surrounded by the vertices C1, C2, C3, and C4 in FIG. 2).
Here, in this embodiment, the first reflective film 551, the second reflective film 552, the third reflective film 553, and the fourth reflective film 554 are provided in the same shape in the filter plan view, so that each reflective film 551 is provided. , 552, 553, and 554 are overlapped with each other, but the present invention is not limited to this. For example, a part of each of the reflective films 551, 552, 553, and 554 may overlap to form a light interference region. In this case, the detection unit 11 is provided in a range corresponding to the light transmitted through the light interference region. It only has to be done.
Here, the first reflection film 551 and the second reflection film 552 constitute a first light interference part 55A, and the third reflection film 553 and the fourth reflection film 554 constitute a second light interference part 55B. .
In this embodiment, the measurement target light incident on the optical module 10 is incident on the third substrate 53 side, and is extracted by the light interference region Ar0 of the first light interference unit 55A and the second light interference unit 55B. Passes through the second substrate 52 and enters the detection unit 11.

[Configuration of the first substrate]
Next, the configuration of the first substrate 51 will be described in detail.
FIG. 4A is a plan view of the first substrate 51 viewed from the second substrate 52 side. FIG. 4B is a plan view of the first substrate 51 viewed from the third substrate 53 side.
The first substrate 51 is a rectangular plate member having vertices C5, C6, C7, and C8. The first substrate 51 has a larger thickness dimension than the second substrate 52 and the third substrate 53, and electrostatic attraction when a voltage is applied between the first electrode 561 and the second electrode 562, There is no bending of the first substrate 51 due to the internal stress of the first electrode 561. On the surface of the first substrate 51 facing the second substrate 52, an electrode arrangement groove 511 and a reflective film installation portion 512 formed by etching are provided. Similarly, on the surface of the first substrate 51 facing the third substrate 53, an electrode arrangement groove 513 and a reflection film installation portion 514 formed by etching are provided.

As shown in FIGS. 2 and 3, the rectangular one end C <b> 5-C <b> 6 of the first substrate 51 protrudes from the one side C <b> 1-C <b> 2 of the substrate overlap portion 555 to the −X side. Part). In addition, the other rectangular ends C7 to C8 of the first substrate 51 protrude from the one side C3 to C4 of the substrate overlapping portion 555 to the + X side, and constitute a third terminal protruding portion 516 (second protruding portion).
Further, the first substrate 51 is formed with electrode extraction grooves 511 </ b> B extending from the two electrode arrangement grooves 511 on the surface facing the second substrate 52, and two electrode arrangement grooves on the surface facing the third substrate 53. An electrode lead groove 513 </ b> B extending from 513 is formed.
One of the two electrode extraction grooves 511 </ b> B extends to the −X side and is connected to the surface of the first terminal protruding portion 515 on the second substrate 52 side, and the other extends to the + X side end of the first substrate 51. Extend. One of the two electrode lead-out grooves 513B extends to the + X side and is connected to the surface of the third terminal protrusion 516 on the third substrate 53 side, and the other extends to the −X side end of the first substrate 51. Extend.
The first terminal protrusion 515 and the electrode extraction groove 511 </ b> B are formed at the same time when the electrode arrangement groove 511 is formed, and are formed to have the same depth as the electrode arrangement groove 511. Similarly, the third terminal protruding portion 516 and the electrode extraction groove 513B are formed at the same time as the electrode arrangement groove 513 is formed, and are formed to have the same depth as the electrode arrangement groove 513.

The electrode arrangement grooves 511 and 513 are formed in an annular shape centering on the center point O of the substrate overlapping portion 555 in the filter plan view. The reflection film installation portions 512 and 514 are formed so as to protrude in the out-of-plane direction from the center portions of the electrode arrangement grooves 511 and 513 in the filter plan view.
A first electrode 561 is provided on the groove bottom surface (electrode installation surface 511A) of the electrode arrangement groove 511, and a first reflection film 551 is provided on the protruding front end surface (reflection film installation surface 512A) of the reflection film installation part 512. It is done. A third electrode 563 is provided on the groove bottom surface (electrode installation surface 513A) of the electrode arrangement groove 513 facing the third substrate 53, and on the protruding front end surface (reflection film installation surface 514A) of the reflection film installation portion 514. The third reflective film 553 is provided.

The first electrode 561 and the third electrode 563 provided on the electrode installation surface 511A and the electrode installation surface 513A are formed in an annular shape centering on the center point O, preferably in an annular shape. The ring shape includes a structure in which a part of the ring shape is divided, for example, a substantially C-shaped structure.
And the 4th electrode 564 extended from the outer periphery of the 1st electrode 561 to the 1st terminal protrusion part 515 is formed in the 1st board | substrate 51, The front-end | tip part of this 1st extraction electrode 565 is a 1st terminal protrusion. The part 515 constitutes a first terminal 565A (first terminal part). The first terminal 565A is exposed on the surface of the variable wavelength interference filter 5 when the variable wavelength interference filter 5 is viewed from the second substrate 52 side, and the first terminal 565A is wired to the exposed portion of the first terminal 565A. Is connected, the voltage control unit 15 can apply a voltage signal to the first electrode 561.
Similarly, a third extraction electrode 567 extending from the outer peripheral edge of the third electrode 563 to the third terminal protruding portion 516 is formed on the first substrate 51, and the distal end portion of the third extraction electrode 567 is the third extraction electrode 567. The terminal protrusion 516 constitutes a third terminal 567A (second terminal portion). The third terminal 567A is exposed on the surface of the tunable interference filter 5 when the tunable interference filter 5 is viewed from the third substrate 53 side, and wiring is connected to the exposed portion of the third terminal 567A. Thus, a voltage signal can be applied from the voltage control unit 15 to the first electrode 561.
As the first electrode 561, the third electrode 563, the first extraction electrode 565, and the third extraction electrode 567, any electrode material may be used as long as it is a conductive film. For example, ITO, Cr / Cr / An Au laminated electrode or the like can be used.
Note that an insulating film may be stacked over the first electrode 561 and the third electrode 563 in order to ensure withstand voltage.

A first reflective film 551 is provided on the reflective film installation surface 512 </ b> A of the reflective film installation unit 512. Similarly, a third reflective film 553 is provided on the reflective film installation surface 514A of the reflective film installation unit 514. As the first reflective film 551 and the third reflective film 553, for example, a metal film such as Ag or an alloy film such as an Ag alloy can be used. Further, as the first reflective film 551 and the third reflective film 553, for example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ may be used. You may use the reflecting film which laminated | stacked, the reflecting film which laminated | stacked the dielectric single layer film | membrane, and the alloy film.
Further, different types of reflective films may be used as the first reflective film 551 and the third reflective film 553. For example, an alloy film may be used as the first reflective film 551, and a dielectric multilayer film may be used as the third reflective film 553.

[Configuration of second substrate]
Next, the configuration of the second substrate 52 will be described in detail. FIG. 5 is a plan view of the second substrate 52 as viewed from the first substrate 51 side.
As shown in FIG. 2, the second substrate 52 is a rectangular plate member having vertices C <b> 1, C <b> 2, C <b> 9, and C <b> 10, and is bonded to the first substrate 51 at the substrate overlap portion 555. As shown in FIGS. 2, 3, and 5, the second substrate 52 has a circular movable portion 521 (first movable portion) centered on the center point O, and is coaxial with the movable portion 521, and is movable. And a holding unit 522 (first holding unit) that holds 521.
As shown in FIGS. 2 and 3, the second substrate 52 has an edge C <b> 7-C <b> 8 of the third terminal protruding portion 516 of the first substrate 51 on the rectangular one end side (+ X side) of the second substrate 52. 2nd terminal protrusion part 523 (1st protrusion part) which protrudes to the + X side rather than is provided. Further, the −X side edge C <b> 1-C <b> 2 of the second substrate 52 coincides with the edge C <b> 1-C <b> 2 of the substrate overlapping portion 555. Thereby, as described above, when the wavelength tunable interference filter 5 is viewed from the second substrate 52 side, the first terminal protruding portion 515 and the first terminal 565A of the first substrate 51 are exposed to the second substrate 52 side. It becomes composition.

  The movable part 521 is formed to have a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 is formed to have the same dimension as the thickness dimension of the second substrate 52. In addition, the movable portion 521 is formed to have a diameter larger than at least the diameter of the outer peripheral edge of the first electrode 561 in the filter plan view. The surface of the movable portion 521 facing the first substrate 51 is a movable surface 521A parallel to the reflective film installation surface 512A, and the second reflective film 552 and the second electrode 562 are provided.

The second reflective film 552 is a reflective film having the same configuration as the first reflective film 551 described above.
The second electrode 562 is formed in an annular shape similar to the first electrode 561 in the filter plan view, and is provided in a region overlapping the first electrode 561. The second substrate 52 is provided with a second extraction electrode 566 extending from the outer peripheral edge of the second electrode 562 to the outer periphery of the second substrate 52. The second extraction electrode 566 extends along one side of the two electrode extraction grooves 511B extending toward the + X side, that is, along the electrode extraction groove 511B in which the first extraction electrode 565 is not provided. The distal end portion of the second extraction electrode 566 constitutes a second terminal 566A (first terminal portion) in the second terminal protruding portion 523. The second terminal 566A is exposed on the surface of the wavelength tunable interference filter 5 when the wavelength tunable interference filter 5 is viewed from the third substrate 53 side, and wiring is connected to the exposed portion of the second terminal 566A. By being connected, a voltage signal can be applied from the voltage control unit 15 to the second electrode 562.
As the second electrode 562 and the second extraction electrode 566, any electrode material may be used as long as it is a conductive film, like the first electrode 561, for example, ITO or Cr / Au laminated layer. An electrode or the like can be used. Further, similarly to the first electrode 561 and the third electrode 563, an insulating film for securing a withstand voltage may be stacked on the second electrode 562.

  Further, an antireflection film may be formed on the movable portion 521 on the surface opposite to the first substrate 51. This antireflection film can be formed by alternately laminating a low refractive index film and a high refractive index film.

The holding part 522 is a diaphragm that surrounds the periphery of the movable part 521, and is formed with less rigidity in the thickness direction than the movable part 521.
For this reason, the holding part 522 is more easily bent than the movable part 521 and can be bent toward the first substrate 51 by a slight electrostatic attraction. At this time, since the movable portion 521 has a thickness dimension larger than that of the holding portion 522 and becomes rigid, even when a force that bends the second substrate 52 due to electrostatic attraction acts, the movable portion 521 is hardly bent. Further, it is possible to prevent the second reflective film 552 formed on the movable portion 521 from being bent.
In the present embodiment, the diaphragm-like holding portion 522 is exemplified, but the present invention is not limited thereto. For example, a configuration in which beam-like holding portions arranged at equiangular intervals around the center point O are provided. It is good.

[Configuration of third substrate]
Next, the configuration of the third substrate 53 will be described in detail. FIG. 6 is a plan view of the third substrate 53 as viewed from the first substrate 51 side.
As shown in FIG. 2, the third substrate 53 is a rectangular plate member having vertices C <b> 3, C <b> 4, C <b> 11, and C <b> 12, and is bonded to the first substrate 51 at the substrate overlap portion 555. As shown in FIGS. 2, 3, and 6, the third substrate 53 has a circular movable portion 531 (second movable portion) centered on the center point O, and is coaxial with the movable portion 531. A holding portion 532 (second holding portion) for holding 531. Since the configuration of the movable portion 531 and the holding portion 532 is the same as that of the movable portion 521 and the holding portion 522 of the second substrate 52, description thereof is omitted here.
Further, as shown in FIGS. 2 and 3, the third substrate 53 has an end C <b> 5-1 of the first terminal protrusion 515 of the first substrate 51 on the rectangular one end side (−X side) of the third substrate 53. A fourth terminal protruding portion 533 (second protruding portion) that protrudes to the −X side from C6 is provided. Also, the + X side edge C3-C4 of the third substrate 53 coincides with the edge C3-C4 of the substrate overlapping portion 555. Thereby, as described above, when the wavelength tunable interference filter 5 is viewed from the third substrate 53 side, the third terminal protruding portion 516 and the third terminal 567A of the first substrate 51 are exposed to the third substrate 53 side. It becomes composition.

A fourth reflective film 554 and a fourth electrode 564 are provided on the movable surface 531A, which is the surface facing the first substrate 51 of the movable portion 531.
As the fourth reflective film 554, a reflective film having the same configuration as that of the third reflective film 553 described above is used.
The fourth electrode 564 is formed in an annular shape similar to the third electrode 563 in the filter plan view, and is provided in a region overlapping the third electrode 563. The third substrate 53 is provided with a fourth extraction electrode 568 extending from the outer peripheral edge of the fourth electrode 564 to the outer peripheral portion of the third substrate 53. The fourth extraction electrode 568 extends along one of the two electrode extraction grooves 513B extending toward the −X side, that is, along the electrode extraction groove 513B in which the third extraction electrode 567 is not provided. . The distal end portion of the fourth extraction electrode 568 constitutes a fourth terminal 568A (second terminal portion) in the fourth terminal protruding portion 533. The fourth terminal 568A is exposed on the surface of the wavelength tunable interference filter 5 when the wavelength tunable interference filter 5 is viewed from the second substrate 52 side, and the fourth terminal 568A is wired to the exposed portion of the fourth terminal 568A. Is connected, the voltage control unit 15 can apply a voltage signal to the fourth electrode 564.
As the fourth electrode 564 and the fourth extraction electrode 568, any electrode material may be used as long as it is a conductive film, like the other electrodes 561, 562, 563, etc., for example, ITO, Cr / Au laminated electrode or the like can be used. Further, an insulating film for ensuring a withstand voltage may be stacked on the fourth electrode 564.

  Further, an antireflection film may be formed on the movable portion 531 on the surface opposite to the first substrate 51. This antireflection film can be formed by alternately laminating a low refractive index film and a high refractive index film.

[Configuration of detector]
Next, returning to FIG. 1, the detection unit 11 of the optical module 10 will be described.
The detection unit 11 receives (detects) light transmitted through the optical interference region Ar0 of the wavelength variable interference filter 5, and outputs a detection signal based on the amount of received light.

[Configuration of I-V Converter, Amplifier, A / D Converter, and Voltage Control Unit]
The IV converter 12 converts the detection signal input from the detection unit 11 into a voltage value and outputs the voltage value to the amplifier 13.
The amplifier 13 amplifies a voltage (detection voltage) corresponding to the detection signal input from the IV converter 12.
The A / D converter 14 converts the detection voltage (analog signal) input from the amplifier 13 into a digital signal and outputs the digital signal to the control circuit unit 20.
The voltage control unit 15 applies a voltage to the electrostatic actuators 56 </ b> A and 56 </ b> B of the wavelength variable interference filter 5 based on the control of the control circuit unit 20. Thus, the electrostatic electrostatic attraction is generated between the first electrode 561 and second electrode 562 of the actuator 56A, the movable portion 521 is displaced to the side first substrate 51, the gap amount g ₁ of the first gap G1 is Set to a predetermined value. Further, the electrostatic electrostatic attraction between the third electrode 563 and fourth electrode 564 is generated in the actuator 56B, a second gap G2 of the gap amount g ₂ is predetermined value movable portion 531 is displaced to the side first substrate 51 Set to

[Configuration of control circuit section]
Next, the control circuit unit 20 of the spectrometer 1 will be described.
The control circuit unit 20 is configured by combining a CPU, a memory, and the like, for example, and controls the overall operation of the spectroscopic measurement apparatus 1. As shown in FIG. 1, the control circuit unit 20 includes a filter driving unit 21, a light amount acquisition unit 22, and a spectral analysis unit 23.
In addition, the control circuit unit 20 includes a storage unit (not shown) that stores various data, and the storage unit stores V-λ data for controlling the electrostatic actuators 56A and 56B.
The V-λ data is set for each of the first optical interference unit 55A and the second optical interference unit 55B. In the V-λ data, a plurality of peak wavelengths of light transmitted through the first light interference unit 55A and the second light interference unit 55B with respect to the voltages applied to the electrostatic actuator 56A and the electrostatic actuator 56B are recorded. ing.
The initial value of the first gap G1 (the gap amount when no voltage is applied to the electrostatic actuator 56A) and the initial value of the second gap G2 (the gap amount when no voltage is applied to the electrostatic actuator 56B) ) Are equal, and the second substrate 52 and the third substrate 53 have the same rigidity in the substrate thickness direction, the same V-λ data may be used.

FIG. 7 is a diagram illustrating an example of transmission characteristics of the variable wavelength interference filter.
The filter drive unit 21 refers to the V-λ data stored in the storage unit, sequentially switches the voltage applied to the electrostatic actuators 56A and 56B of the wavelength variable interference filter 5, and transmits light that passes through the wavelength variable interference filter 5. The wavelengths of are sequentially switched.
Then, the filter driver 21, to the electrostatic actuator 56A and the electrostatic actuator 56B, so that the gap amount g ₂ of the gap amount g ₁ and the second gap G2 of the first gap G1 is different gap amount, Apply voltage. At this time, the filter driving unit 21 refers to the V-λ data and, as shown in FIG. 7, one of the peak wavelengths (broken line in FIG. 7) in the optical characteristics of the first optical interference unit 55A and the second optical interference. The voltage applied to each of the electrostatic actuators 56A and 56B is controlled so that one of the peak wavelengths (the one-dot chain line in FIG. 7) in the optical characteristics of the portion 55B overlaps. As a result, the light having the overlapping peak wavelength (solid line in FIG. 7) is transmitted from the wavelength variable interference filter 5.

For example, when the light that can be detected by the detection unit 11 is visible light and near-infrared light (for example, from 360 nm to 1200 nm) and it is desired to extract light at 550 nm from the measurement target light, the filter driving unit 21 includes the first gap gap distance _{g 1} is 550nm next G1, the gap distance _{g 2} of the second gap G2 such that 275 nm, setting the voltage applied electrostatic actuator 56A, the 56B. In this case, the light that can be transmitted through the first optical interference unit 55A is 1100 nm light having a primary peak wavelength, 550 nm light having a secondary peak wavelength, and 366 nm light having a tertiary peak wavelength (fourth peak wavelength ( After 275 nm), it is not detected by the detection unit 11). On the other hand, the light that can be transmitted through the second optical interference unit 55B is light having a primary peak wavelength of 550 nm (after the secondary peak wavelength (275 nm) is not detected by the detection unit 11). Thereby, the light which permeate | transmits the wavelength variable interference filter 5 turns into 550 nm light with which the peak wavelength of 55 A of 1st optical interference parts and the 2nd optical interference part 55B overlap.

The light quantity acquisition unit 22 acquires the light quantity detected by the detection unit 11 and stores it in the storage unit.
The spectroscopic analysis unit 23 analyzes the spectral spectrum of the measurement target light based on the light amount for each wavelength acquired by the light amount acquisition unit 22 and stored in the storage unit.

[Manufacturing method of tunable interference filter]
Next, a manufacturing method for the wavelength variable interference filter as described above will be described with reference to the drawings.
FIG. 8 is a diagram illustrating a manufacturing process of the first substrate 51. FIG. 9 is a diagram illustrating a manufacturing process of the second substrate 52. FIG. 10 is a diagram showing a chip manufacturing process.

[Manufacture of the first substrate]
In order to manufacture the first substrate 51, first, as shown in FIG. 8A, a first glass substrate M1 which is a manufacturing material of the first substrate 51 is prepared, and the surface roughness Ra of the quartz glass substrate is prepared. Polish both surfaces until the thickness becomes 1 nm or less.
Next, as shown in FIG. 8B, the substrate surface of the first glass substrate M1 is processed by etching.
Specifically, a resist is applied to the substrate surface of the first glass substrate M1, and the applied resist is exposed and developed by a photolithography method, whereby the reflection film installation surface 512A and the reflection film installation surface 514A are formed. Is patterned so as to open. Here, in the present embodiment, a plurality of first substrates 51 are formed from one first glass substrate M1. Therefore, in this step, a resist pattern is formed on the first glass substrate M1 so that the plurality of first substrates 51 are manufactured in a state of being arranged in parallel in an array.
Then, wet etching using, for example, hydrofluoric acid is performed on both surfaces of the first glass substrate M1. At this time, the etching is performed to the depth of the reflection film installation surface 512A and the reflection film installation surface 514A. Thereafter, a resist is formed so that the electrode placement groove 511, the electrode lead groove 511B, the electrode placement groove 513, the electrode lead groove 513B, the first terminal protrusion 515, and the third terminal protrusion 516 are opened. Further, wet etching is performed.
Thereby, as shown in FIG. 8B, the first glass substrate M1 in which the substrate shape of the first substrate 51 is determined is formed.

Thereafter, an electrode material for forming the first electrode 561, the third electrode 563, the first extraction electrode 565, and the third extraction electrode 567 is formed on both surfaces of the first glass substrate M1, and a photolithography method or the like is used. Pattern.
Further, when forming an insulating layer on the first electrode 561 and the third electrode 563, after the electrode formation, for example, a SiO ₂ film having a thickness of about 100 nm is formed on the entire first glass substrate M1, for example, by plasma CVD or the like. . The SiO ₂ on the first terminal 565A and the third terminal 567A is removed by, for example, dry etching.

Next, a first reflective film 551 and a third reflective film 553 are formed on the reflective film installation part 512 and the reflective film installation part 514, respectively.
Here, in this embodiment, an Ag alloy is used as the first reflective film 551 and the third reflective film 553. When a metal film such as an Ag alloy or an alloy film such as an Ag alloy is used as the reflective film, a photolithography method or the like is used after a reflective film (metal film or alloy film) is formed on the surface of the first glass substrate M1. Pattern.
In the case of forming a dielectric multilayer film as the reflective film, patterning can be performed by, for example, a lift-off process. In this case, a resist (lift-off pattern) is formed on a portion other than the reflective film formation portion on the first glass substrate M1 by a photolithography method or the like. Thereafter, a material for forming the first reflective film 551 and the second reflective film 552 (for example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ ) is sputtered or vapor deposited. The film is formed by Then, after the first reflective film 551 and the second reflective film 552 are formed, unnecessary portions of the film are removed by lift-off.
In addition, when using a different kind of reflective film as the 1st reflective film 551 and the 3rd reflective film 553, respectively, the above-mentioned process is implemented separately and a reflective film is formed.
Thus, the first glass substrate M1 in which the first substrates 51 as shown in FIG. 8C are arranged in a plurality of arrays is manufactured.

[Second substrate and third substrate manufacturing process]
Next, a process for manufacturing the second substrate 52 will be described.
In order to manufacture the second substrate 52, first, as shown in FIG. 9A, a second glass substrate M2 which is a forming material of the second substrate 52 is prepared, and the surface roughness of the second glass substrate M2 is prepared. Both surfaces are precisely polished until Ra is 1 nm or less. And a resist is apply | coated to the whole surface of the 2nd glass substrate M2, and the apply | coated resist is exposed and developed by the photolithographic method, and the location in which the holding part 522 is formed is patterned.
Next, the holding part 522 and the movable part 521 are formed as shown in FIG. 9B by performing wet etching on the second glass substrate M2. Thereby, the 2nd glass substrate M2 in which the board | substrate shape of the 2nd board | substrate 52 was determined is manufactured.

Next, the second electrode 562 and the second extraction electrode 566 are formed on one surface (the surface facing the first substrate 51) of the second glass substrate M2.
Specifically, in the same manner as the first electrode 561, an electrode material is formed on the second glass substrate M2, and is patterned using a photolithography method or the like, whereby the second electrode 562 and the second extraction electrode 566 are used. Form.
Thereafter, the second reflective film 552 is formed on the movable surface 521A. The second reflective film 552 can be formed by the same method as the first reflective film 551.
As described above, the second glass substrate M2 in which the second substrates 52 as shown in FIG. 9C are arranged in a plurality of arrays is manufactured.

The third substrate 53 can be manufactured by the same method as the second substrate 52.
That is, a third glass substrate M3 (see FIG. 10), which is a material for forming the third substrate 53, is prepared, and both surfaces of the third glass substrate M3 are precisely polished, and then the movable portion 531 and the holding portion 532 are etched to form the third substrate 53. Form. Then, the fourth electrode 564 and the fourth extraction electrode 568 are formed on the surface of the third glass substrate M3 facing the first substrate 51, and the fourth reflection film 554 is formed on the movable surface 531A.
Thereby, the 3rd glass substrate M3 by which the 3rd board | substrate 53 is arrange | positioned at multiple array form is manufactured.

[Chip forming process]
Next, a chip forming process for manufacturing the wavelength variable interference filter 5 by bonding the first glass substrate M1, the second glass substrate M2, and the third glass substrate M3 will be described.
In this chip formation step, first, plasma mainly composed of polyorganosiloxane is formed in a region corresponding to the substrate overlap portion 555 of the first glass substrate M1 and a region corresponding to the substrate overlap portion 555 of the second glass substrate M2. A polymerized film is formed by, for example, a plasma CVD method. The thickness of the plasma polymerization film may be, for example, 10 nm to 1000 nm.

Then, in order to providing the activation energy to the plasma-polymerized film of the first glass substrate M1 and the second glass substrate M2, performing the O ₂ plasma treatment or UV treatment. In the case of the O ₂ plasma treatment, the O ₂ flow rate is 30 cc / min, the pressure is 27 Pa, and the RF power is 200 W for 30 seconds. In the case of UV treatment, the treatment is performed for 3 minutes using excimer UV (wavelength 172 nm) as a UV light source.
After applying activation energy to the plasma polymerized film, the alignment of the first glass substrate M1 and the second glass substrate M2 is adjusted, and the first glass substrate M1 and the second glass substrate M2 are stacked via the plasma polymerized film. In addition, a load of, for example, 10 kgf is applied to the joint portion for 10 minutes. Thereby, the 1st glass substrate M1 and the 2nd glass substrate M2 are joined.

In the present embodiment, the positions of the substrate edges of the first substrate 51, the second substrate 52, and the third substrate 53 along the X direction are different. Therefore, when the cutting process of taking out each wavelength variable interference filter 5 in units of chips is performed after joining the first glass substrate M1, the second glass substrate M2, and the third glass substrate M3, the edge of the first substrate 51 It becomes difficult to cut appropriately.
For this reason, in this embodiment, after joining the 1st glass substrate M1 and the 2nd glass substrate M2, first, only the 1st glass substrate M1 is cut | disconnected along the cutting line L1 as shown by the broken line of FIG. To do. For this cutting, for example, laser cutting or the like can be used.

Then, the 1st glass substrate M1 and the 3rd glass substrate M3 are joined by a plasma polymerization film | membrane using the method similar to joining of the 1st glass substrate M1 and the 2nd glass substrate M2. Then, the second glass substrate M2 and the third glass substrate M3 are cut along cutting lines L2 and L3 as indicated by broken lines in FIG.
Thereby, the variable wavelength interference filter 5 of a chip unit is manufactured from the joined body of the first glass substrate M1, the second glass substrate M2, and the third glass substrate M3.

[Operational effects of the first embodiment]
In the spectroscopic measurement apparatus 1 according to the first embodiment as described above, in the wavelength tunable interference filter 5, the second substrate 52 is bonded to one surface of the first substrate 51, and the third substrate 53 is bonded to the other surface. It is joined. And the 1st reflective film 551 provided in the 1st board | substrate 51 and the 2nd reflective film 552 provided in the 2nd board | substrate 52 mutually oppose via the 1st gap G1, and comprise 55 A of 1st optical interference parts. The first light interference section 55A, by changing the voltage applied to the electrostatic actuator 56A, it is possible to change the gap distance g ₁ of the first gap G1 as appropriate. In addition, the third reflective film 553 provided on the first substrate 51 and the 54 provided on the third substrate 53 are opposed to each other via the second gap G2 to constitute the second light interference portion 55B. the electrostatic actuator 56B, it is possible to change the gap distance g ₂ of the second gap G2 as appropriate.
Then, in the spectroscopic measurement device 1, by the filter driving section 21, the gap distance g ₂ of the gap amount g ₁ and the second gap G2 of the first gap G1 set to different gap size, and the first light interference section 55A The first gap G1 and the second gap G2 so that one of the plurality of order peak wavelengths that pass through and the one of the plurality of order peak wavelengths that pass through the second optical interference unit 55B overlap each other. Set the gap amount. Thereby, even if measurement object light having a wide wavelength band is incident, light having a specific peak wavelength can be transmitted. Therefore, light having a desired peak wavelength can be received and detected by the detection unit 11, and an accurate amount of light having the peak wavelength can be detected. Therefore, the spectroscopic measurement device 1 can accurately analyze the accurate spectral spectrum of the measurement target light.

In the present embodiment, the first substrate 51, the second substrate 52, and the third substrate 53 are each formed of glass substrates M1, M2, and M3 that are transparent to visible light.
For this reason, it is possible to cover a wide band from the visible light range to the near infrared range as the wavelength range of light that can be extracted by the tunable interference filter 5. Spectroscopic measurements can be performed on this.
Further, the glass substrate can be easily processed by wet etching, and the manufacturing efficiency can be improved.

Furthermore, in this embodiment, the second substrate 52 is provided on the outer side of the movable portion 521 provided with the second reflective film 552 and the movable portion 521, and holds the movable portion 521 so as to be able to advance and retreat with respect to the first substrate 51. Holding part 522. Similarly, the third substrate 53 is provided with a movable portion 531 on which the fourth reflective film 554 is provided, and a holding portion 532 that is provided outside the movable portion 531 and holds the movable portion 531 with respect to the first substrate 51 so as to advance and retreat. With.
In such a configuration, the movable parts 521 and 531 can be easily displaced by bending the holding parts 522 and 532 having a smaller thickness than the movable parts 521 and 531. Therefore, the voltage when changing the first gap G1 and the second gap G2 can be reduced, and power saving can be achieved. Further, since the movable parts 521 and 531 have a thickness dimension larger than that of the holding parts 522 and 532, even when the movable parts 521 and 531 are displaced toward the first substrate 51, the bending of the movable parts 521 and 531 is suppressed. Therefore, the bending of the second reflective film 552 provided on the movable part 521 and the fourth reflective film 554 provided on the movable part 531 can be suppressed, and a decrease in resolution in the wavelength variable interference filter 5 can be suppressed.

Moreover, in this embodiment, the other wavelength board | substrate etc. do not intervene in the 1st gap G1 or the 2nd gap G2, and the transmissive wavelength range can be expanded.
For example, if the first reflecting film 551 and the fourth reflective layer 554 so as to constitute a second light interference section 55B, the gap amount g ₂ of the second gap G2 is (thickness of the first substrate 51 S) <g ₂ <(thickness dimension S of the first substrate 51 + distance between the fourth reflective film 554 and the first substrate 51 in the initial state). Therefore, in such a case, the gap amount g ₂ of the second gap G ₂ cannot be set to be equal to or smaller than the thickness dimension of the first substrate 51. In general, the initial gap amount of the second gap G2 needs to be formed to be about 1 μm in the visible light range although it depends on the wavelength range to be measured. Therefore, in such a configuration, it is necessary to reduce the thickness of the first substrate 51, and there is a possibility that the resolution is lowered due to the bending of the first substrate 51, the bending of the first reflective film 551, and the like.
On the other hand, in the present embodiment, the second light interference portion 55B is formed by the third reflective film 553 and the fourth reflective film 554, and between the third reflective film 553 and the fourth reflective film 554, there is another since member is not interposed, the gap amount _{g 2} of the second gap G2 is, 0 _<g 2 becomes <(initial gap amount of the second gap G2). Therefore, it is possible to widen the setting range of the gap distance g ₂ of the second gap G2, it is possible to widen the wavelength range of light to be transmitted by the wavelength-tunable interference filter 5. In addition, since the first substrate 51 can be formed to have a thickness dimension that can resist the electrostatic attractive force by the electrostatic actuator 56A and the electrostatic actuator 56B, the first reflective film 551 as described above (the first reflective film 551) There is no reduction in resolution due to bending of the three reflecting films 553), and high-resolution light can be transmitted.

In the wavelength tunable interference filter 5 of the present embodiment, the first substrate 51 includes a first terminal 565A provided in the first terminal protruding portion 515 protruding from the substrate overlapping portion 555 to the −X side, and the first substrate 565A protruding to the + X side. A third terminal 567 </ b> A is provided on the three-terminal protrusion 516.
In such a configuration, since the first terminal 565A and the third terminal 567A are exposed on the surface of the wavelength variable interference filter 5, wiring is easily connected to the first terminal 565A and the third terminal 567A. can do.
The second substrate 52 is provided with a second terminal protruding portion 523 that protrudes from the substrate overlapping portion 555 to the + X side with respect to the third terminal protruding portion 516. 566A is provided. Similarly, the third substrate 53 is provided with a fourth terminal protruding portion 533 that protrudes from the substrate overlapping portion 555 to the −X side with respect to the first terminal protruding portion 515, and the fourth terminal protruding portion 533 includes a fourth terminal protruding portion 533. A terminal 568A is provided. Accordingly, since the second terminal 566A and the third terminal 567A are exposed on the surface of the variable wavelength interference filter 5, wiring can be easily connected to the second terminal 566A and the fourth terminal 568A. .

[Second Embodiment]
Next, a second embodiment of the present invention will be described based on the drawings.
The second embodiment is a modification of the tunable interference filter 5 in the first embodiment, and the other configurations are the same as those in the first embodiment.
That is, in the first embodiment, the first terminal protruding portion 515, the third terminal protruding portion 516, the second terminal protruding portion 523, and the fourth terminal protruding portion 533 are protruded along the X direction, that is, X In the cross-sectional view of the wavelength tunable interference filter 5 along the direction, a configuration in which a stepped step is formed by the first substrate 51, the second substrate 52, and the third substrate 53 is illustrated. In such a wavelength variable interference filter 5, after the first glass substrate M1 and the second glass substrate M2 are joined at the time of manufacture, only the first glass substrate M1 is once cut, and then the third glass substrate M3 is attached. After joining, it was necessary to cut | disconnect the 2nd glass substrate M2 and the 3rd glass substrate M3, and there existed a subject that a complicated operation | work accompanied with cutting out the wavelength variable interference filter 5 of a chip unit.
On the other hand, in 2nd embodiment, in order to reduce the complicated operation | work in such a manufacturing process, the 1st terminal protrusion part 515, the 3rd terminal protrusion part 516, the 2nd terminal protrusion part 523, the 4th terminal A configuration in which the protruding direction of the protruding portion 533 is different from that of the first embodiment is adopted.
Hereinafter, the variable wavelength interference filter 5A according to the second embodiment will be described with reference to the drawings. In the following description of the embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted or simplified.

[Configuration of wavelength tunable interference filter]
FIG. 11 is a plan view showing a schematic configuration of a variable wavelength interference filter 5A of the second embodiment. 12 is a cross-sectional view of the variable wavelength interference filter 5A of FIG. 11 taken along line AA. 13 is a cross-sectional view of the variable wavelength interference filter 5A of FIG. 11 taken along line BB.
As shown in FIG. 11, in the variable wavelength interference filter 5A of the present embodiment, the first substrate 51 is formed in a rectangular plate shape having vertices C1, C5, C6, and C7. The second substrate 52 is formed in a rectangular plate shape having vertices C8, C9, C10, and C4. The third substrate 53 is formed in a rectangular plate shape having vertices C2, C11, C12, and C13. Accordingly, the substrate overlapping portion 555 where these substrates 51, 52, 53 all overlap is a rectangular region surrounded by the vertices C1, C2, C3, C4 as shown in FIG.

In such a configuration, the first terminal protrusion 515 (first protrusion) of the first substrate 51 is an area surrounded by points C4, C10, C6, and C7 in FIG. It protrudes in the + X direction from C3-C4.
Further, the third terminal protruding portion 516 (second protruding portion) of the first substrate 51 is a region surrounded by the points C2, C5, C6, C11 in FIG. 11, and from the end C2-C3 of the substrate overlapping portion 555. It is provided to protrude in the + Y direction on the Y axis orthogonal to the X axis.
The second terminal protrusion 523 (first protrusion) of the second substrate 52 is an area surrounded by the points C1, C5, C9, and C8, and protrudes in the −X direction from the end C1-C2 of the substrate overlap portion 555. Is provided. The fourth terminal protrusion 533 (second protrusion) of the third substrate 53 is an area surrounded by the points C1, C7, C12, and C13, and protrudes from the end C1-C4 of the substrate overlap portion 555 in the −Y direction. Is provided.
In other words, in the present embodiment, the terminal projecting portions 515, 516, 523, and 533 are provided so as to project in different directions from different sides of the substrate overlapping portion 555.
As in the first embodiment, the first terminal protrusion 515 is provided with a first terminal 565A connected to the first electrode 561, and the third terminal protrusion 516 is connected to the third electrode 563. A third terminal 567A is provided, a second terminal protrusion 523 is provided with a second terminal 566A connected to the second electrode 562, and a fourth terminal protrusion 533 is connected to the fourth electrode 564. A fourth terminal 568A is provided.

Further, in the present embodiment, as shown in FIGS. 11 and 12, the −X side edge C <b> 1-C <b> 5 of the first substrate 51 is the X coordinate of the −X side edge C <b> 2-C <b> 13 of the third substrate 53. Matches. Further, the + X side edge of the first substrate 51 (the protruding side edge of the first terminal protruding portion 515) C6-C7 coincides with the X coordinate of the + X side edge C11-C12 of the third substrate 53.
Furthermore, as illustrated in FIGS. 11 and 13, the −Y side edge C <b> 1-C <b> 7 of the first substrate 51 coincides with the Y coordinate of the −Y side edge C <b> 4-C <b> 8 of the second substrate 52. Further, the + Y side edge of the first substrate 51 (the protruding side edge of the third terminal protruding portion 516) C5-C6 coincides with the Y coordinate of the + Y side edge C9-C10 of the second substrate 52.

[Manufacture of tunable interference filter]
In the method of manufacturing the wavelength tunable interference filter 5A of the present embodiment, the manufacturing steps of the substrates 51, 52, and 53 are the same as those of the first embodiment. In the present embodiment, a plurality of first substrates 51 are arrayed. A first glass substrate M1 arranged in a shape, a second glass substrate M2 arranged in a plurality of second substrates 52 in an array, and a third glass substrate M3 arranged in a plurality of third substrates 53 are manufactured.
FIG. 14 is a diagram showing a chip manufacturing process in the present embodiment.
As described above, after manufacturing the glass substrates M1, M2, and M3, in the present embodiment, as shown in FIG. 14, these glass substrates M1, M2, and M3 are bonded. As a bonding method, the same method as in the first embodiment, that is, siloxane bonding using a plasma polymerized film can be used.

And after joining each glass substrate M1, M2, M3, a cutting process is implemented along the cutting lines L4, L5, and L6 shown with the broken line in FIG. Here, in this embodiment, as shown in FIGS. 11 to 13, the first substrate 51 and the third substrate 53 have the same end on the −X side. Further, since the + X side edges of the first substrate 51 and the third substrate 53 are the −X side edges of the first substrate 51 and the third substrate 53 of the adjacent chips, the first substrate 51 and the third substrate. The ends on the + X side of 53 also coincide with each other. Therefore, in the cutting step, as shown in FIG. 14, the first substrate 51 and the third substrate 53 can be cut simultaneously along the cutting line L4.
On the other hand, the −X side end of the second substrate 52 is a part of the second terminal protrusion 523 and is not joined to the first substrate 51, so only the second substrate 52 is cut along the cutting line L 5. Just cut it. The + X side edge of the second substrate 52 is also the −X side edge of the second substrate 52 of the adjacent chip, and is not joined to the first substrate 51 in the same manner. Only the two substrates 52 need be cut.

  Similarly, since the first substrate 51 and the second substrate 52 have the −Y side end and the + Y side end aligned with each other, the first substrate 51 and the second substrate 52 are simultaneously aligned along the cutting line L6. The substrate 52 can be cut. Further, the end on the −Y side of the third substrate 53 is a part of the fourth terminal protruding portion 533 and is not joined to the first substrate 51, so that a cutting line (not shown) along the vertex C 12 -C 13 is shown. ), Only the third substrate 53 may be cut.

  As described above, in this embodiment, the cutting process can be performed after the first glass substrate M1, the second glass substrate M2, and the third glass substrate M3 are joined, and the manufacturing efficiency is higher than that in the first embodiment. Can be improved.

[Third embodiment]
Next, a third embodiment of the present invention will be described based on the drawings.
In the spectroscopic measurement device 1 of the first embodiment, the wavelength variable interference filter 5 is directly provided to the optical module 10. However, some optical modules have a complicated configuration, and it may be difficult to directly provide the variable wavelength interference filter 5 particularly for a miniaturized optical module. In the present embodiment, an optical filter device that allows the wavelength variable interference filter 5 and the wavelength variable interference filter 5A of the second embodiment to be easily installed even for such an optical module will be described below.
FIG. 15 is a cross-sectional view showing a schematic configuration of an optical filter device according to the third embodiment of the present invention.

As shown in FIG. 15, the optical filter device 600 includes a wavelength tunable interference filter 5 and a housing 601 that houses the wavelength tunable interference filter 5. In the present embodiment, the wavelength variable interference filter 5 is illustrated as an example, but the wavelength variable interference filter 5A of the second embodiment may be used.
The housing 601 includes a base substrate 610, a lid 620, a base side glass substrate 630, and a lid side glass substrate 640.

  The base substrate 610 is configured by, for example, a single layer ceramic substrate. On the base substrate 610, the second substrate 52 of the variable wavelength interference filter 5 is installed. The second substrate 52 may be disposed on the base substrate 610 by, for example, being disposed via an adhesive layer or the like, and disposed by being fitted to another fixing member or the like. May be. In addition, a light passage hole 611 is formed in the base substrate 610 in a region facing the light interference region Ar0. And the base side glass substrate 630 is joined so that this light passage hole 611 may be covered. As a method for joining the base side glass substrate 630, for example, glass frit joining using a glass frit that is a piece of glass that has been melted at a high temperature and rapidly cooled, adhesion by an epoxy resin, or the like can be used.

Inner terminal portions 615 corresponding to the respective terminal portions 565A, 566A, 567A, and 568A of the wavelength variable interference filter 5 are provided on the base inner side surface 612 of the base substrate 610 facing the lid 620. For example, FPC (Flexible Printed Circuits) 615A can be used for connection between the terminal portions 565A, 566A, 567A, and 568A and the inner terminal portion 615, for example, Ag paste, ACF (Anisotropic Conductive Film), ACP (Anisotropic). Join with Conductive Paste etc. In addition, when maintaining the internal space 650 in a vacuum state, it is preferable to use Ag paste with little outgas. Further, the connection is not limited to the connection by the FPC 615A, and wiring connection by wire bonding or the like may be performed, for example.
In addition, the base substrate 610 has through holes 614 corresponding to positions where the respective inner terminal portions 615 are provided, and the respective inner terminal portions 615 are interposed via conductive members filled in the through holes 614. The base substrate 610 is connected to an outer terminal portion 616 provided on the base outer surface 613 opposite to the base inner surface 612.
A base joint 617 that is joined to the lid 620 is provided on the outer periphery of the base substrate 610.

As shown in FIG. 15, the lid 620 includes a lid joint 624 that is joined to the base joint 617 of the base substrate 610, a side wall 625 that continues from the lid joint 624 and rises away from the base substrate 610, A top surface portion 626 that is continuous from the side wall portion 625 and covers the first substrate 51 side of the wavelength variable interference filter 5 is provided. The lid 620 can be formed of an alloy such as Kovar or a metal, for example.
The lid 620 is tightly bonded to the base substrate 610 by bonding the lid bonding portion 624 and the base bonding portion 617 of the base substrate 610.
As this joining method, for example, in addition to laser welding, soldering using silver brazing, sealing using a eutectic alloy layer, welding using low melting glass, glass adhesion, glass frit bonding, epoxy resin Adhesion etc. are mentioned. These bonding methods can be appropriately selected depending on the materials of the base substrate 610 and the lid 620, the bonding environment, and the like.

  The top surface portion 626 of the lid 620 is parallel to the base substrate 610. In the top surface portion 626, a light passage hole 621 is formed in a region facing the light interference region Ar0 of the wavelength variable interference filter 5. And the lid side glass substrate 640 is joined so that this light passage hole 621 may be covered. As a method for bonding the lid-side glass substrate 640, for example, glass frit bonding, adhesion using an epoxy resin, or the like can be used as in the case of bonding the base-side glass substrate 630.

[Operational effects of the third embodiment]
In the optical filter device 600 of the present embodiment, since the wavelength tunable interference filter 5 is protected by the housing 601, it is possible to prevent changes in the characteristics of the wavelength tunable interference filter 5 due to foreign matters, gases contained in the atmosphere, and the like. It is possible to prevent the wavelength tunable interference filter 5 from being damaged due to mechanical factors. In addition, since intrusion of charged particles can be prevented, charging of the first electrode 561 and the second electrode 562 can be prevented. Therefore, the generation of Coulomb force due to charging can be suppressed, and the parallelism of the reflective films 551 and 552 can be more reliably maintained.

For example, when the wavelength tunable interference filter 5 manufactured in a factory is transported to an assembly line for assembling an optical module or an electronic device, the wavelength tunable interference filter 5 protected by the optical filter device 600 is transported safely. It becomes possible.
In addition, since the optical filter device 600 is provided with the outer terminal portion 616 exposed on the outer peripheral surface of the housing 601, wiring can be easily performed even when the optical filter device 600 is incorporated into an optical module or an electronic device. Become.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

In the first embodiment and the second embodiment, the first terminal 565A is provided in the first terminal protrusion 515 and the second terminal 566A is provided in the second terminal protrusion 523. However, the present invention is not limited to this. For example, only one of the first substrate 51 and the second substrate 52 is provided with a first protrusion that protrudes from the substrate overlap portion 555, and both the first terminal 565A and the second terminal 566A are provided in the first protrusion. May be provided. That is, a first terminal portion (first terminal 565A) for applying a voltage to the electrostatic actuator 56A, which is the first actuator, on the first protrusion provided on either the first substrate 51 or the second substrate 52. The second terminal 566A) may be provided.
Similarly, the third terminal 567A is provided in the third terminal protruding portion 516 and the fourth terminal 568A is provided in the fourth terminal protruding portion 533. However, the present invention is not limited to this.
For example, only one of the first substrate 51 and the third substrate 53 is provided with a second protrusion that protrudes from the substrate overlap portion 555, and both the third terminal 567A and the fourth terminal 568A are provided on the second protrusion. May be provided. That is, a second terminal portion (third terminal 567A) for applying a voltage to the electrostatic actuator 56B, which is the second actuator, is applied to the second protrusion provided on either the first substrate 51 or the third substrate 53. The fourth terminal 568A) may be provided.

  Furthermore, each terminal protrusion part 515,516,523,533 is not provided, but each terminal part 565A, 566A, 567A, 568A is exposed by notching a part of each board | substrate 51,52,53, etc. It is good.

In each of the above embodiments, the resist in which the electrode placement groove 511, the electrode lead groove 511B, the electrode placement groove 513, the electrode lead groove 513B, the first terminal protrusion 515, and the third terminal protrusion 516 are formed is opened. The configuration in which the first gap G1 and the second gap G2 have the same initial gap amount by forming and performing wet etching is exemplified, but the present invention is not limited thereto.
For example, the first gap G1 and the second gap G2 may have different initial gap amounts.
In this case, for example, when the fixed substrate 51 is manufactured, the formation process of the reflection film installation surface 512A and the reflection film installation surface 514A is performed as a separate process, or the reflection film installation surface 512A and the reflection film installation surface 514A are formed. Only on the other hand, the groove depth may be changed by further etching.
Moreover, the thickness dimension of the bonding film at the time of bonding of the first glass substrate M1 and the second glass substrate M2 is different from the thickness dimension of the bonding film at the time of bonding of the first glass substrate M1 and the third glass substrate M3. Thus, the first gap G1 and the second gap G2 may be set to different initial gap amounts.
In such a configuration, for example, when the secondary peak wavelength extracted between the first gaps G1 matches the primary peak wavelength extracted between the second gaps G2, the initial gap of the second gap G2 is set to the first gap. By setting the gap G1 smaller than the initial gap, the voltage value at the time of voltage control can be reduced, and power saving can be achieved.
For example, if the target light to be extracted light of 550nm, a filter drive unit 21, as the gap amount _{g 1} of the first gap G1 is 550nm, and the gap amount _{g 2} of the second gap G2 and 275 nm, electrostatic A voltage to be applied to the electric actuators 56A and 56B is set. Here, when the initial gaps of the first gap G1 and the second gap G2 are each 1 μm, the filter driving unit needs to displace the movable unit 521 by 450 nm and the movable unit 531 by 725 nm. On the other hand, when the initial gap amount of the first gap G1 is 1 μm and the initial gap of the second gap G2 is 600 nm, the filter driving unit only has to displace the movable unit 531 by 325 nm. The electric power for driving can be made small.

In the embodiments described above, as the first actuator and the second actuator of the variable wavelength interference filter 5, 5A, the gap distance g ₂ of the gap amount g ₁ and the second gap G2 of the first gap G1 by electrostatic attraction by applying a voltage Although the electrostatic actuators 56 </ b> A and 56 </ b> B to be varied are exemplified, the present invention is not limited to this.
For example, instead of the electrodes 561, 562, 563, and 564, an electromagnetic actuator having a coil may be used.
Further, a piezoelectric actuator may be used instead of the electrostatic actuators 56A and 56B. In this case, for example, the lower electrode layer, the piezoelectric film, and the upper electrode layer are stacked on the holding portions 522 and 532, and the voltage applied between the lower electrode layer and the upper electrode layer is varied as an input value, thereby the piezoelectric film The holding portions 522 and 532 can be bent by expanding and contracting.
Further, different actuators may be used for the first actuator and the second actuator. For example, the first actuator may be an electrostatic actuator 56A and the second actuator may be an electromagnetic actuator.

  Moreover, although the electrostatic actuator 56A comprised by the annular | circular shaped 1st electrode 561 and the 2nd electrode 562 was illustrated as a 1st actuator, it is not limited to this. For example, it is good also as a structure which forms the electrode (an inner side electrode, an outer side electrode) on two circular rings from which diameter size differs centering on the center point O in both 51 and 52. FIG. In this case, the gap amount of the first gap G1 can be controlled with high accuracy by the two electrostatic actuators. The same applies to the second actuator, and the gap amount of the second gap G2 may be adjusted using a plurality of actuators.

Further, each substrate 51, 52, 53, charging and antistatic electrodes for preventing the reflection film 551,552,553,554, and the gap amount _{g 1} of the first gap G1, gap of the second gap G2 the amount g ₂ for measuring on the basis of the electrostatic capacitance may be such structure further comprising a capacitance measuring electrodes or the like.

  In each said embodiment, although the 1st terminal protrusion part 515 was formed simultaneously with the electrode arrangement | positioning groove | channel 511 and the electrode extraction groove | channel 511B, the surface by which the 2nd board | substrate side becomes the same plane as 511A of electrode installation surfaces was illustrated. However, the present invention is not limited to this. For example, the first terminal protrusion 515 may be configured such that the first terminal 565 </ b> A is provided on the same plane as the surface bonded to the second substrate 52 without being subjected to the etching process when the first substrate 51 is manufactured. . The same applies to the third terminal protruding portion 516, and the third terminal 567 </ b> A is formed on the same plane as the surface to be joined to the third substrate 53 without being subjected to the etching process on the formation position of the third terminal protruding portion 516. May be provided.

Moreover, although the spectroscopic measurement apparatus 1 has been exemplified in the first embodiment as the electronic apparatus of the present invention, the wavelength variable interference filter, the optical filter device, the optical module, and the electronic apparatus of the present invention may be used in various other fields. it can.
For example, it can be used as a light-based system for detecting the presence of a specific substance. As such a system, for example, an in-vehicle gas leak detector that detects a specific gas with high sensitivity by adopting a spectroscopic measurement method using the variable wavelength interference filter of the present invention, or a photoacoustic rare gas detection for a breath test. A gas detection device such as a vessel can be exemplified.
An example of such a gas detection device will be described below with reference to the drawings.

FIG. 16 is a schematic diagram illustrating an example of a gas detection device including a wavelength variable interference filter.
FIG. 17 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As shown in FIG. 16, the gas detection device 100 includes a sensor chip 110, a flow path 120 including a suction port 120A, a suction flow path 120B, a discharge flow path 120C, and a discharge port 120D, a main body 130, It is configured with.
The main body unit 130 includes a sensor unit cover 131 having an opening through which the flow channel 120 can be attached, a discharge unit 133, a housing 134, an optical unit 135, a filter 136, a wavelength variable interference filter 5, a light receiving element 137 (detection unit), and the like And a control unit 138 that processes the detected signal and controls the detection unit, a power supply unit 139 that supplies power, and the like. The optical unit 135 emits light, and a beam splitter 135B that reflects light incident from the light source 135A toward the sensor chip 110 and transmits light incident from the sensor chip toward the light receiving element 137. And lenses 135C, 135D, and 135E. Instead of the variable wavelength interference filter 5, a variable wavelength interference filter 5A or an optical filter device 600 may be disposed.
As shown in FIG. 17, an operation panel 140, a display unit 141, a connection unit 142 for interfacing with the outside, and a power supply unit 139 are provided on the surface of the gas detection device 100. When the power supply unit 139 is a secondary battery, a connection unit 143 for charging may be provided.
Further, as shown in FIG. 17, the control unit 138 of the gas detection apparatus 100 controls a signal processing unit 144 configured by a CPU or the like, a light source driver circuit 145 for controlling the light source 135A, and the variable wavelength interference filter 5. Voltage control unit 146, a light receiving circuit 147 that receives a signal from the light receiving element 137, a sensor chip detection that reads a code of the sensor chip 110 and receives a signal from a sensor chip detector 148 that detects the presence or absence of the sensor chip 110 A circuit 149, a discharge driver circuit 150 for controlling the discharge means 133, and the like are provided.

Next, operation | movement of the above gas detection apparatuses 100 is demonstrated below.
A sensor chip detector 148 is provided inside the sensor unit cover 131 at the upper part of the main body unit 130, and the sensor chip detector 148 detects the presence or absence of the sensor chip 110. When the signal processing unit 144 detects the detection signal from the sensor chip detector 148, the signal processing unit 144 determines that the sensor chip 110 is attached, and displays a display signal for displaying on the display unit 141 that the detection operation can be performed. put out.

  For example, when the operation panel 140 is operated by the user and an instruction signal to start the detection process is output from the operation panel 140 to the signal processing unit 144, the signal processing unit 144 first sends the signal processing unit 144 to the light source driver circuit 145. A light source activation signal is output to activate the light source 135A. When the light source 135A is driven, laser light having a single wavelength and stable linear polarization is emitted from the light source 135A. The light source 135A includes a temperature sensor and a light amount sensor, and the information is output to the signal processing unit 144. When the signal processing unit 144 determines that the light source 135A is stably operating based on the temperature and light quantity input from the light source 135A, the signal processing unit 144 controls the discharge driver circuit 150 to operate the discharge unit 133. Thereby, the gas sample containing the target substance (gas molecule) to be detected is guided from the suction port 120A to the suction channel 120B, the sensor chip 110, the discharge channel 120C, and the discharge port 120D. The suction port 120A is provided with a dust removal filter 120A1 to remove relatively large dust, some water vapor, and the like.

The sensor chip 110 is a sensor that incorporates a plurality of metal nanostructures and uses localized surface plasmon resonance. In such a sensor chip 110, an enhanced electric field is formed between the metal nanostructures by the laser light, and when gas molecules enter the enhanced electric field, Raman scattered light and Rayleigh scattered light including information on molecular vibrations are generated. Occur.
These Rayleigh scattered light and Raman scattered light enter the filter 136 through the optical unit 135, and the Rayleigh scattered light is separated by the filter 136, and the Raman scattered light enters the wavelength variable interference filter 5. Then, the signal processing unit 144 controls the voltage control unit 146 to adjust the voltage applied to the wavelength variable interference filter 5, and causes the wavelength variable interference filter 5 to split the Raman scattered light corresponding to the gas molecule to be detected. . Thereafter, when the dispersed light is received by the light receiving element 137, a light reception signal corresponding to the amount of received light is output to the signal processing unit 144 via the light receiving circuit 147.
The signal processing unit 144 compares the spectrum data of the Raman scattered light corresponding to the gas molecule to be detected obtained as described above and the data stored in the ROM, and determines whether or not the target gas molecule is the target gas molecule. To determine the substance. Further, the signal processing unit 144 displays the result information on the display unit 141 or outputs the result information from the connection unit 142 to the outside.

  16 and 17 exemplify the gas detection device 100 that performs gas detection from the Raman scattered light obtained by spectrally dividing the Raman scattered light by the wavelength variable interference filter 5. You may use as a gas detection apparatus which specifies gas classification by detecting the light absorbency of. In this case, a gas sensor that allows gas to flow into the sensor and detects light absorbed by the gas in the incident light is used as the optical module of the present invention. A gas detection device that analyzes and discriminates the gas flowing into the sensor by such a gas sensor is an electronic apparatus of the present invention. Even in such a configuration, it is possible to detect a gas component using the wavelength variable interference filter.

In addition, the system for detecting the presence of a specific substance is not limited to the detection of the gas as described above, but a non-invasive measuring device for saccharides by near-infrared spectroscopy, and non-invasive information on food, living body, minerals, etc. A substance component analyzer such as a measuring device can be exemplified.
Hereinafter, a food analyzer will be described as an example of the substance component analyzer.

FIG. 18 is a diagram illustrating a schematic configuration of a food analysis apparatus which is an example of an electronic apparatus using the variable wavelength interference filter 5.
As shown in FIG. 18, the food analysis apparatus 200 includes a detector 210 (optical module), a control unit 220, and a display unit 230. The detector 210 includes a light source 211 that emits light, an imaging lens 212 into which light from the measurement target is introduced, a wavelength variable interference filter 5 that splits the light introduced from the imaging lens 212, and the dispersed light. And an imaging unit 213 (detection unit) for detecting. Instead of the variable wavelength interference filter 5, a variable wavelength interference filter 5A or an optical filter device 600 may be disposed.
In addition, the control unit 220 controls the light source control unit 221 that controls the turning on / off of the light source 211 and the brightness control at the time of lighting, the voltage control unit 222 that controls the wavelength variable interference filter 5, and the imaging unit 213. , A detection control unit 223 that acquires a spectral image captured by the imaging unit 213, a signal processing unit 224, and a storage unit 225.

  In the food analyzer 200, when the system is driven, the light source 211 is controlled by the light source control unit 221, and light is irradiated from the light source 211 to the measurement object. Then, the light reflected by the measurement object enters the wavelength variable interference filter 5 through the imaging lens 212. The variable wavelength interference filter 5 is applied with a voltage capable of dispersing a desired wavelength under the control of the voltage control unit 222, and the dispersed light is imaged by an imaging unit 213 configured by, for example, a CCD camera or the like. The captured light is accumulated in the storage unit 225 as a spectral image. In addition, the signal processing unit 224 controls the voltage control unit 222 to change the voltage value applied to the wavelength tunable interference filter 5, and acquires a spectral image for each wavelength.

Then, the signal processing unit 224 performs arithmetic processing on the data of each pixel in each image accumulated in the storage unit 225, and obtains a spectrum at each pixel. In addition, the storage unit 225 stores, for example, information related to food components with respect to the spectrum, and the signal processing unit 224 analyzes the obtained spectrum data based on the information related to food stored in the storage unit 225. The food component contained in the detection target and its content are obtained. Moreover, a food calorie, a freshness, etc. are computable from the obtained food component and content. Furthermore, by analyzing the spectral distribution in the image, it is possible to extract a portion of the food to be inspected that has reduced freshness, and to detect foreign substances contained in the food. Can also be implemented.
Then, the signal processing unit 224 performs processing for causing the display unit 230 to display information such as the components and contents of the food to be examined, the calories, and the freshness obtained as described above.

FIG. 18 shows an example of the food analysis apparatus 200, but it can also be used as a non-invasive measurement apparatus for other information as described above with a substantially similar configuration. For example, it can be used as a biological analyzer for analyzing biological components such as measurement and analysis of body fluid components such as blood. As such a bioanalytical device, for example, a device that detects ethyl alcohol as a device that measures a body fluid component such as blood, it can be used as a drunk driving prevention device that detects the drunk state of the driver. Further, it can also be used as an electronic endoscope system provided with such a biological analyzer.
Furthermore, it can also be used as a mineral analyzer for performing component analysis of minerals.

Furthermore, the variable wavelength interference filter, optical module, and electronic apparatus of the present invention can be applied to the following devices.
For example, it is possible to transmit data using light of each wavelength by changing the intensity of light of each wavelength over time. In this case, light of a specific wavelength is transmitted by a wavelength variable interference filter provided in the optical module. The data transmitted by the light of the specific wavelength can be extracted by separating the light and receiving the light at the light receiving unit, and the electronic data having such a data extraction optical module can be used to extract the light data of each wavelength. By processing, optical communication can be performed.

Further, the electronic apparatus can be applied to a spectroscopic camera, a spectroscopic analyzer, or the like that captures a spectroscopic image by dispersing light with the variable wavelength interference filter of the present invention. An example of such a spectroscopic camera is an infrared camera incorporating a wavelength variable interference filter.
FIG. 19 is a schematic diagram showing a schematic configuration of the spectroscopic camera. As shown in FIG. 19, the spectroscopic camera 300 includes a camera body 310, an imaging lens unit 320, and an imaging unit 330 (detection unit).
The camera body 310 is a part that is gripped and operated by a user.
The imaging lens unit 320 is provided in the camera body 310 and guides incident image light to the imaging unit 330. Further, as shown in FIG. 19, the imaging lens unit 320 includes an objective lens 321, an imaging lens 322, and a variable wavelength interference filter 5 provided between these lenses.
The imaging unit 330 includes a light receiving element, and images the image light guided by the imaging lens unit 320.
In such a spectroscopic camera 300, a spectral image of light having a desired wavelength can be captured by transmitting light having a wavelength to be imaged by the variable wavelength interference filter 5.

Furthermore, the wavelength tunable interference filter of the present invention may be used as a bandpass filter. For example, only light in a narrow band centered on a predetermined wavelength is tunable out of light in a predetermined wavelength range emitted from a light emitting element. It can also be used as an optical laser device that spectrally transmits through an interference filter.
In addition, the tunable interference filter of the present invention may be used as a biometric authentication device, and can be applied to authentication devices such as blood vessels, fingerprints, retinas, and irises using light in the near infrared region and visible region.

  Furthermore, an optical module and an electronic device can be used as a concentration detection device. In this case, the infrared energy (infrared light) emitted from the substance is spectrally analyzed by the variable wavelength interference filter, and the analyte concentration in the sample is measured.

  As described above, the tunable interference filter, the optical module, and the electronic device of the present invention can be applied to any device that splits predetermined light from incident light. Since the wavelength tunable interference filter according to the present invention can split a plurality of wavelengths with one device as described above, it is possible to accurately measure a spectrum of a plurality of wavelengths and detect a plurality of components. it can. Therefore, compared with the conventional apparatus which takes out a desired wavelength with a plurality of devices, it is possible to promote downsizing of the optical module and the electronic apparatus, and for example, it can be suitably used as a portable or in-vehicle optical device.

  In addition, the specific structure for carrying out the present invention can be appropriately changed to other structures and the like within a range in which the object of the present invention can be achieved.

  DESCRIPTION OF SYMBOLS 1 ... Spectrometer (electronic device) 5,5A ... Wavelength variable interference filter, 10 ... Optical module, 11 ... Detection part, 20 Control circuit part, 21 ... Filter drive part, 51 ... First board | substrate (board | substrate), 52 ... 2nd board | substrate, 53 ... 3rd board | substrate, 55A ... 1st light interference part, 55B ... 2nd light interference part, 56A ... Electrostatic actuator (1st actuator), 56B ... Electrostatic actuator (2nd actuator), 100 ... gas detection device (electronic device), 200 ... food analysis device (electronic device), 300 ... spectroscopic camera (electronic device), 515 ... first terminal protrusion (first protrusion), 516 ... third terminal protrusion ( Second projecting part), 521... Movable part (first movable part), 522... Holding part (second retaining part), 523... Second terminal projecting part (first projecting part), 531. Part), 532 ... holding part ( Second holding portion), 533... Fourth terminal protruding portion (second protruding portion), 551... First reflecting film, 552. Second reflecting film, 553. Third reflecting film, 554. Fourth reflecting film, 561. 1st electrode, 562 ... 2nd electrode, 563 ... 3rd electrode, 564 ... 4th electrode, 565A ... 1st terminal part, 566A ... 2nd terminal part, 567A ... 3rd terminal part, 568A ... 4th terminal part, 600: optical filter device, 601: housing, G1: first gap, G2: second gap.

Claims (12)

A first substrate;
A second substrate disposed opposite the first substrate;
A first reflective film provided on a surface of the first substrate facing the second substrate;
A second reflective film provided on a surface of the second substrate facing the first substrate and facing the first reflective film via a gap between the first reflective films;
A first actuator for changing the gap between the first reflective films;
A third substrate disposed opposite to a surface opposite to the surface facing the second substrate of the first substrate;
A third reflective film provided on a surface of the first substrate facing the third substrate;
A fourth reflective film provided on a surface of the third substrate facing the first substrate and facing the third reflective film via a gap between the second reflective films;
A second actuator for changing the gap between the second reflective films;
Comprising
The first reflection film, the second reflection film, the third reflection film, and the fourth reflection film in a plan view of the first substrate, the second substrate, and the third substrate viewed from the substrate thickness direction. is, Ri at least some heavy Do each other,
The first actuator changes the gap between the first reflective films by applying a voltage,
The second actuator changes the gap between the second reflective films by applying a voltage,
In the plan view, at least one of the first substrate and the second substrate includes a first protruding portion that protrudes outward from the outer peripheral edge of the other,
The first projecting portion is provided with a first terminal portion for applying a voltage to the first actuator,
In the plan view, at least one of the first substrate and the third substrate includes a second protruding portion that protrudes outward from the outer peripheral edge of the other,
The wavelength variable interference filter according to claim 2, wherein a second terminal portion for applying a voltage to the second actuator is provided at the second protrusion .   The tunable interference filter according to claim 1,
  The first actuator includes a first electrode provided on a surface of the first substrate facing the second substrate, and a second electrode provided on the second substrate and facing the first electrode via a predetermined gap. With electrodes,
  The second actuator includes a third electrode provided on a surface of the first substrate facing the third substrate, and a fourth electrode provided on the third substrate and facing the third electrode via a predetermined gap. With electrodes,
  The first terminal portion provided in the first protrusion includes a first terminal connected to the first electrode and a second terminal connected to the second electrode,
  The second terminal portion provided on the second protrusion includes a third terminal connected to the third electrode and a fourth terminal connected to the fourth electrode.
  A tunable interference filter characterized by that. A first substrate;
A second substrate disposed opposite the first substrate;
A first reflective film provided on a surface of the first substrate facing the second substrate;
A second reflective film provided on a surface of the second substrate facing the first substrate and facing the first reflective film via a gap between the first reflective films;
A first actuator for changing the gap between the first reflective films;
A third substrate disposed opposite to a surface opposite to the surface facing the second substrate of the first substrate;
A third reflective film provided on a surface of the first substrate facing the third substrate;
A fourth reflective film provided on a surface of the third substrate facing the first substrate and facing the third reflective film via a gap between the second reflective films;
A second actuator for changing the gap between the second reflective films;
Comprising
The first reflection film, the second reflection film, the third reflection film, and the fourth reflection film in a plan view of the first substrate, the second substrate, and the third substrate viewed from the substrate thickness direction. is, Ri at least some heavy Do each other,
A first terminal protruding portion in which a part of the first substrate protrudes outside the outer peripheral edge of the second substrate;
A second terminal projecting portion in which a part of the second substrate projects outside the outer peripheral edge of the first substrate;
A third terminal protruding portion in which a part of the first substrate protrudes outside the outer peripheral edge of the third substrate;
A fourth terminal protruding portion in which a part of the third substrate protrudes outside the outer peripheral edge of the first substrate;
With
The first actuator includes a first electrode provided on a surface of the first substrate facing the second substrate, and a second electrode provided on the second substrate and facing the first electrode via a predetermined gap. With electrodes,
The second actuator includes a third electrode provided on a surface of the first substrate facing the third substrate, and a fourth electrode provided on the third substrate and facing the third electrode via a predetermined gap. With electrodes,
The first terminal protrusion is provided with a first terminal connected to the first electrode,
The second terminal protrusion is provided with a second terminal connected to the second electrode,
The third terminal protrusion is provided with a third terminal connected to the third electrode,
The fourth terminal protrusion is provided with a fourth terminal connected to the fourth electrode.
A tunable interference filter characterized by that.   The tunable interference filter according to claim 3,
  In the plan view,
  The first substrate, the second substrate, and the third substrate have rectangular overlapping portions that overlap each other, and the first terminal protrusion, the second terminal protrusion, and the third terminal protrusion Part and the fourth terminal projecting part project from different sides of the board overlapping part in different directions,
  The second substrate protrudes from the substrate overlapping portion in the same direction as the protruding direction of the third terminal protruding portion and by the same dimension,
  The third substrate protrudes from the substrate overlapping portion in the same direction as the protruding direction of the first terminal protruding portion and by the same dimension.
  A tunable interference filter characterized by that. In the wavelength variable interference filter according to any one of claims 1 to 4 ,
The variable wavelength interference filter, wherein the first substrate, the second substrate, and the third substrate have translucency with respect to visible light. The tunable interference filter according to claim 5 ,
The wavelength variable interference filter, wherein the first substrate, the second substrate, and the third substrate are a quartz substrate or a glass substrate. The variable wavelength interference filter according to any one of claims 1 to 6,
The second substrate has a first movable part and a first holding part provided around the first movable part in the plan view,
The second reflective film is provided on the first movable part. A wavelength tunable interference filter, wherein: The variable wavelength interference filter according to any one of claims 1 to 7,
The third substrate has a second movable part and a second holding part provided around the second movable part in the plan view,
The fourth reflective film is provided on the second movable part. A wavelength tunable interference filter, wherein: The wavelength variable interference filter according to any one of claims 1 to 8,
An optical filter device, characterized in that it comprises a a housing for housing the variable wavelength interference filter. The wavelength variable interference filter according to any one of claims 1 to 8,
A detector for detecting light;
Comprising
The first reflective film, the second reflective film, the third reflective film, and the fourth reflective film in a plan view of the first substrate, the second substrate, and the third substrate viewed from the substrate thickness direction. The light interference area is composed of the overlapping areas,
The optical module, wherein the detection unit detects light extracted by the optical interference region. The wavelength variable interference filter according to any one of claims 1 to 8,
A control unit for controlling the first actuator and the second actuator;
An electronic apparatus comprising: The electronic apparatus according to claim 1 1,
The control unit sets the second inter-reflective film gap to a value different from the first inter-reflective film gap, and within the predetermined wavelength range to be measured, the first reflective film and the second reflective film In the state where one of the plurality of peak wavelengths extracted by the above and one of the plurality of peak wavelengths extracted by the third reflection film and the fourth reflection film overlap, the gap between the first reflection films and the An electronic device characterized by setting a gap between the second reflecting films.

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