JP2006350125A - Optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device in which light having various wavelengths is surely demultiplexed. <P>SOLUTION: The optical device shown in Fig. 1 passes the light having a specific wavelength band among incident light L1 and comprises: a first structure body U1 which has a pair of reflection films 312a and 312b and a first displacement means which makes the reflection films approach to and separate from each other of the reflection films, and is so composed that the light L2 having a wavelength band corresponding to the distance h1 between the reflection films is passed; a second structure body U2 which has a pair of reflection films 312c and 312d and a second displacement means which makes the reflection films approach to and separate from each other of the reflection films, and is so composed that the light L3 having a wavelength band corresponding to the distance h2 between the reflection films is passed to the outside. The optical device is composed by arranging the first structure body U1 and the second structure body U2 along the optical axis of the incident light L1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical device.

In order to separate (extract) light having a specific wavelength from light having various wavelengths, that is, to perform wavelength separation, a tunable filter (Optical Tunable Filter) is generally used. As this wavelength tunable filter, for example, one described in Patent Document 1 is known.
The wavelength tunable filter of Patent Document 1 includes a plate-like movable part, a first reflective film formed on one surface of the movable part, a drive part that displaces the movable part in the thickness direction by electrostatic force, The substrate includes a substrate fixed to the movable portion, and a second reflective film formed on the surface of the substrate on the movable portion side. In the wavelength tunable filter having such a configuration, the wavelength separation is performed by repeatedly reflecting between the first reflecting film and the second reflecting film (gap) to cause interference, and light corresponding to the gap is emitted. This is done by emitting light to the outside.

  Now, in this wavelength tunable filter, as the first reflective film and the second reflective film come closer due to the operation of the drive unit, that is, the displacement of the movable part, the first reflective film and the second reflective film The electrostatic force (attraction force) increases in magnitude and eventually exceeds the electrostatic force controlled by the drive unit. For this reason, the first reflective film and the second reflective film are in close contact, that is, no gap is formed between the first reflective film and the second reflective film, and wavelength separation cannot be performed. There was a problem of becoming.

Japanese Examined Patent Publication No. 4-46369

  An object of the present invention is to provide an optical device capable of reliably performing wavelength separation on light having various wavelengths.

Such an object is achieved by the present invention described below.
The optical device of the present invention is an optical device that transmits light in a specific wavelength region among incident light,
A pair of first reflecting films and a first displacing means for moving the first reflecting films closer to and away from each other, and setting an interval between the first reflecting films by the first displacing means; Then, in this state, the light is incident, reflection is repeated between the pair of first reflection films, and interference is generated, so that light in a wavelength region corresponding to the interval between the first reflection films is obtained. A first structure configured to be able to pass through;
A pair of second reflecting films and a second displacing means for moving the second reflecting films closer to and away from each other, and setting an interval between the second reflecting films by the second displacing means; In this state, light that has passed through the first structure is incident, and reflection is repeated between the pair of second reflection films to cause interference. A second structure that is configured to transmit light in a wavelength range corresponding to the interval to the outside;
The first structure and the second structure are arranged along the optical axis of the incident light.
Thereby, an optical device capable of reliably performing wavelength separation on light having various wavelengths is obtained.

In the optical device of the present invention, by setting the interval between the first reflective films and the interval between the second reflective films to be different from each other, the wavelength range of light transmitted through the first structure is It is preferable that the wavelength range of light transmitted through the second structure is different.
Accordingly, the light transmission condition of the optical device can be a combination of the light transmission condition of the first structure and the light transmission condition of the second structure.

In the optical device according to the aspect of the invention, it is preferable that the first structure and the second structure share a wavelength range of light to be removed.
Thereby, wavelength separation can be performed in two stages in the first structure body and the second structure body, and wavelength separation with a higher degree of freedom is possible.
In the optical device according to the aspect of the invention, by setting at least one of the pair of first reflection films and the pair of second reflection films to be in a non-parallel state when setting an interval between them, the transmission of the light is performed. It is preferable that it is comprised so that it may prevent.
Thereby, the optical device functions as a switch.

In the optical device according to the aspect of the invention, it is preferable that at least one of the first displacement unit and the second displacement unit is operated by the action of Coulomb force.
Thereby, a board | substrate can be displaced to the thickness direction.
In the optical device according to the aspect of the invention, the first displacing unit supports the pair of first reflection films, and has a pair of first substrates having light transmission properties, and is disposed to face the first substrates. It is preferable to have a pair of first electrode portions.
Thereby, by energizing the electrode portion, each substrate and each reflective film in the first structure can be stably driven (displaced) in the vertical direction, that is, in the thickness direction.

In the optical device according to the aspect of the invention, the second displacing unit supports the pair of second reflective films and has a pair of light-transmitting second substrates, and is disposed opposite to the second substrates. It is preferable to have a pair of second electrode portions.
Thereby, by energizing the electrode portion, each substrate and each reflective film in the second structure pair can be stably driven (displaced) in the vertical direction, that is, in the thickness direction.

In the optical device of the present invention, the first structure includes a pair of housings having a pair of recesses capable of housing the first reflective film and the first displacement means,
It is preferable to have a spacer that joins the housings so that the recesses face each other.
Thereby, it is possible to prevent unintentional contact with the substrate from the outside of the housing body of the first structure.

In the optical device of the present invention, the second structure includes a pair of housings having a pair of recesses capable of accommodating the second reflective film and the second displacement means,
It is preferable to have a spacer that joins the housings so that the recesses face each other.
Thereby, it can prevent contacting the board | substrate from the outer side of the housing main body of a 2nd structure unintentionally.

In the optical device according to the aspect of the invention, it is preferable that the first structure and the second structure are bonded via an intermediate layer.
Thereby, a 1st structure and a 2nd structure can be optically joined, and both joint strength can be improved.
In the optical device of the present invention, the refractive index of the intermediate layer is approximately equal to the refractive index of the portion of the first structure through which the light is transmitted and the refractive index of the portion of the second structure through which the light is transmitted. Preferably equal.
Thereby, when light permeate | transmits an intermediate | middle layer, unintentional reflection of light can be suppressed.

DESCRIPTION OF EMBODIMENTS Hereinafter, an optical device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
1 is a cross-sectional view (side view) showing a first embodiment of the optical device of the present invention, FIG. 2 is a cross-sectional view (plan view) taken along line AA of the optical device shown in FIG. 1, and FIGS. These are the figures (the figure which shows a manufacturing process typically) explaining the manufacturing method of the optical device shown in FIG. 1, respectively. In the following description, the upper side in FIGS. 1 and 4 to 7 is referred to as “upper”, and the lower side is referred to as “lower”.

  The optical device 1 shown in FIG. 1 is, for example, a device that transmits light (interference light) L3 in a specific wavelength region out of the light L1 incident in the optical device 1, that is, a device that functions as a wavelength variable filter. The optical device 1 has a first structure and a second structure. In addition, the first structure includes a pair of structures (structures 10A and 10B) disposed to face each other, and the second structure includes a pair of structures (structures) disposed to face each other. Body 10C, 10D). In other words, in this embodiment, the optical device 1 uses a pair of structures (first structure and second structure) arranged opposite to each other as a structural unit, and the light L1 incident on the structural unit is incident on the optical device 1. It is arranged along the optical axis and laminated (bonded). In the configuration shown in the figure, the structure 10D is positioned on the lowermost side, and the structures 10C, 10B, and 10A are stacked in this order. Hereinafter, the configuration of each unit will be described.

As shown in FIG. 1, the structure 10A in the first structure U1 includes a housing 2a, a substrate 3a that can be accommodated in the housing 2a, and a reflective film 312a provided on the lower surface (one surface) of the substrate 3a. And an electrode part 23a for displacing the substrate 3a.
As shown in FIG. 2, the substrate 3a is substantially circular in plan view. Thereby, the board | substrate 3a can be stabilized and can be displaced efficiently.

The substrate 3a is made of a light-transmitting material, and the material is not particularly limited. For example, silicon (Si) is preferably used. When silicon is used, the disk-shaped substrate 3a can be easily manufactured (formed).
In addition, the thickness (average) of the substrate 3a is appropriately selected depending on the constituent material, application, and the like, and is not particularly limited, but is preferably about 1 to 500 μm, and more preferably about 10 to 100 μm.
The reflective film 312a is paired with a reflective film 312b described later.
The reflection film 312a has a circular shape in plan view, and is provided concentrically (supported) on the substrate 3a. Thereby, the light L1 incident on the optical device 1 can be efficiently reflected.

The reflective film 312a is formed (configured) with a multilayer film.
As a constituent material of the multilayer film, for example, SiO ₂ (silicon oxide film), Ta ₂ O ₅ , SiN (silicon nitride film) and the like are preferable. By appropriately using these, the reflection film 312a having a very high reflectance can be obtained. By laminating these layers alternately, a multilayer film (reflection film 312a) having a predetermined thickness can be provided.

  By setting (adjusting) the thickness, the number of layers, and the material of each layer of the multilayer film, a multilayer film capable of reflecting light of a predetermined wavelength can be formed (characteristics can be changed). For example, the reflectance can be adjusted by setting the thickness of each layer, and the wavelength of the reflected light can be adjusted by setting the number of layers. Thereby, the reflective film 312a having desired characteristics can be easily formed.

The housing 2a is paired with a housing 2b described later. The housing 2a includes a block-shaped housing main body 20a, a silicon layer (silicon film) 33 provided on the lower surface of the housing main body 20a, and a support portion 32 that supports the substrate 3a so that it can be displaced (moved). Yes.
The housing body 20a is provided with a recess 21a. The recess 21a is paired with a recess 21b provided in the housing main body 20b described later, and the shape thereof is substantially cylindrical. The substrate 3a is concentrically accommodated (installed) in the recess 21a. By providing such a recess 21a, it is possible to prevent inadvertent contact with the substrate 3a from the outside of the housing body 20a.

In addition, it is preferable to form the recessed part 21a by performing an etching process from the surface (lower surface) of the housing main body 20a so that it may mention later. The depth of the recess 21a is appropriately selected depending on the use of the optical device 1 and the like and is not particularly limited, but is preferably about 1 to 100 μm.
The housing body 20a is made of a light transmissive material. Examples of this material include soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, sodium borosilicate glass, and non-alkali glass, and silicon. A glass containing mobile ions that can be moved by application is preferred. Thereby, it becomes possible to join an object to be joined to the housing body 20a by anodic bonding.

Examples of the movable ions include alkali ions such as sodium ions, potassium ions, and lithium ions, as well as aluminum ions, and alkali metal ions are particularly preferable. Thereby, anodic bonding can be performed more firmly.
From such a viewpoint, it is preferable to use soda glass, potassium glass, sodium borosilicate glass, or the like.
Further, the thickness (average) of the housing body 20a is appropriately selected depending on the constituent material, application, etc., and is not particularly limited, but is preferably about 10 to 2000 μm, more preferably about 100 to 1000 μm. .

The silicon layer 33 is provided on the entire lower surface of the housing body 20a.
Four support portions 32 having a strip shape and having elasticity (flexibility) are formed on the inner peripheral portion 331 of the silicon layer 33 so as to protrude (see FIG. 2). These support portions 32 are provided at equal intervals along the circumferential direction of the inner peripheral portion of the silicon layer 33.
In addition, it is preferable that the constituent material of each support part 32 is comprised with the silicon | silicone similarly to the board | substrate 3a and the silicon layer 33. Thereby, as will be described later, each support portion 32, the substrate 3a, and the silicon layer 33 can be integrally formed. In other words, it is possible to omit forming the support portions 32, the substrate 3a, and the silicon layer 33 individually. For this reason, the number of parts which comprise the optical device 1 can be reduced, and the man-hour for manufacturing the optical device 1 can be reduced.

Further, the lower surface of the silicon layer 33 (the surface in contact with the spacer 11 described later) preferably has high smoothness (small surface roughness).
Specifically, the surface roughness Ra of the bonding surface is preferably 50 nm or less, and preferably 20 nm or less. As a result, the spacer 11 can be bonded even at a relatively low temperature. In addition, it is possible to more reliably prevent the occurrence of variations in bonding strength, voids, and the like at the bonding interface.
The number of support portions 32 formed is not limited to four, and may be two, three, five, or more, for example. Further, the shape of the support portion 32 is not limited to the illustrated shape.

As shown in FIG. 1, the electrode part 23a is provided in the bottom part (upper part) 211 of the recessed part 21a. Thereby, it can prevent contacting the electrode part 23a unintentionally from the outer side of the housing main body 20a (housing 2a).
Further, by energizing the electrode portion 23a, a potential difference is generated between the electrode portion 23a and the substrate 3a, and a Coulomb force (electrostatic force) is generated. Thereby, the board | substrate 3a can be displaced to the thickness direction. As a result, the substrate 3a and a later-described substrate 3b can be displaced so as to approach and separate from each other, and thereby the reflective film 312a and a later-described reflective film 312b can be displaced so as to approach and separate from each other.

The electrode portion 23a is composed of an electrode plate 233 having an annular shape (ring shape) (see FIG. 2).
The electrode portion 23a (electrode plate 233) faces the edge portion 31 of the substrate 3a. As shown in FIG. 2, the edge 31 of the substrate 3 a is included in the electrode plate 233 in plan view.
By providing such an electrode portion 23a, when the electrode portion 23a is energized, the substrate 3a can be stably driven (displaced) in the vertical direction, that is, in the thickness direction of the substrate 3a.

The electrode part 23a is made of a conductive material. The material is not particularly limited. For example, metals such as Cr, Al, Al alloys, Ni, Zn, and Ti, resins in which carbon or titanium is dispersed, silicon such as polycrystalline silicon (polysilicon), amorphous silicon, and the like. , Silicon nitride, transparent conductive material such as ITO, Au and the like.
In addition, the thickness (average) of the electrode part 23a is appropriately selected depending on the constituent material, application, etc., and is not particularly limited, but is preferably about 0.01 to 20 μm, more preferably 1 to 3 μm. preferable.
Further, as shown in FIG. 1, it is preferable that antireflection films 311a and 210a are formed in the recess 21a.

The antireflection film 311a has substantially the same shape as the reflection film 312a. The antireflection film 311a is provided concentrically with the substrate 3a (reflective film 312a) on the surface opposite to the lower surface on which the reflective film 312a of the substrate 3a is formed, that is, the upper surface.
The antireflection film 210a has substantially the same shape as the antireflection film 311a. The antireflection film 210a is provided on the bottom 211 of the recess 21a so as to face the antireflection film 311a, that is, to overlap the antireflection film 311a in plan view.

By forming such antireflection films 311a and 210a, reflection of the light L1 incident on the optical device 1 and interference light interfering between the reflection film 312a and the reflection film 312b is suppressed, and the light is transmitted. It can be transmitted efficiently.
Further, each of the antireflection films 311a and 210a is formed of a multilayer film.
As a constituent material of this multilayer film, for example, SiO ₂ (silicon oxide film), Ta ₂ O ₅ , SiN (silicon nitride film) and the like are preferable. By appropriately using these, antireflection films 311a and 210a having very low reflectance (very high transmittance) can be obtained. By laminating these layers alternately, a multilayer film having a predetermined thickness can be provided.

By setting (adjusting) the thickness, number of layers, and material of each layer of the multilayer film, a multilayer film capable of transmitting or reflecting light of a predetermined wavelength can be formed (characteristics can be changed). ). In addition, the antireflection rate (transmittance) can be adjusted by setting the thickness of each layer, and the wavelength of transmitted light can be adjusted by setting the number of layers in each layer.
In addition, it is preferable that at least one of the antireflection films 311a and 210a has an insulating property. Thereby, the short circuit (short circuit) with the electrode part 23a and the board | substrate 3a can be prevented.

As shown in FIG. 1, an antireflection film 100a is preferably provided on the upper surface of the housing body 20a. Thereby, reflection of the light L1 incident on the optical device 1 can be suppressed, and the light L1 can be transmitted efficiently.
In addition, it is preferable that the antireflection film 100a is formed of a multilayer film, similarly to the antireflection films 311a and 210a.

As shown in FIG. 1, the structure 10B in the first structure U1 includes a housing 2b, a substrate 3b that can be accommodated in the housing 2b, and a reflection provided on the upper surface of the substrate 3b (surface on the substrate 3a side). A film 312b and an electrode part 23b for displacing the substrate 3b are provided.
Similar to the substrate 3a, the substrate 3b has a substantially circular shape in plan view. As a result, the substrate 3b can be stably and efficiently displaced.

The substrate 3b is disposed so as to face the substrate 3a through the gap 25, that is, to substantially overlap the substrate 3a in plan view.
The substrate 3b is made of a light-transmitting material, and the material is not particularly limited. For example, it is preferable to use silicon (Si). When silicon is used, the disk-shaped substrate 3b can be easily manufactured (formed).
In addition, the thickness (average) of the substrate 3b is appropriately selected depending on the constituent material, application, and the like, and is not particularly limited, but is preferably about 1 to 500 μm, and more preferably about 10 to 100 μm.

The reflective film 312b is paired with the above-described reflective film 312a.
The reflection film 312b has a circular shape in plan view, and is provided concentrically (supported) on the substrate 3b. Thereby, the light L1 incident on the optical device 1 can be efficiently reflected.
The reflective film 312b is formed (configured) with a multilayer film. As a constituent material of the multilayer film, for example, the materials mentioned in the description of the reflective film 312a can be used.

The housing 2b makes a pair with the housing 2a. The housing 2b includes a block-shaped housing main body 20b, a silicon layer 33 provided on the upper surface of the housing main body 20b, and a support portion 32 that supports the substrate 3b so that it can be displaced (moved).
In addition, it is preferable that the constituent material of each support part 32 is comprised with the silicon | silicone similarly to the board | substrate 3b and the silicon layer 33. FIG. Thereby, as will be described later, the support portions 32, the substrate 3b, and the silicon layer 33 can be integrally formed. As a result, it is possible to obtain effects such as the reduction in the number of parts and the number of man-hours during manufacturing as described above. In addition, since the description about the silicon layer 33 and the support part 32 has been mentioned above, description about these is abbreviate | omitted here.

  The housing body 20b is provided with a recess 21b that faces the recess 21a. The concave portion 21b is paired with the concave portion 21a provided in the housing main body 20a, and the shape thereof is substantially cylindrical. The substrate 3b is concentrically accommodated (installed) in the recess 21b. By providing such a recess 21b, it is possible to prevent inadvertent contact with the substrate 3b from the outside of the housing body 20b (optical device 1).

In addition, it is preferable to form the recessed part 21b by performing an etching process from the surface (upper surface) of the housing main body 20b. Moreover, the depth of the recessed part 21b is suitably selected by the use etc. of the optical device 1, and although it does not specifically limit, It is preferable that it is about 1-100 micrometers.
The housing body 20b is made of a light transmissive material. As this material, for example, the materials mentioned in the description of the housing main body 20a can be used.
Further, the thickness (average) of the housing body 20b is appropriately selected depending on the constituent material, application, etc., and is not particularly limited, but is preferably about 10 to 2000 μm, more preferably about 100 to 1000 μm. .

As shown in FIG. 1, the electrode part 23b is provided in the bottom part (lower part) 211 of the recessed part 21b. Thereby, it can prevent contacting the electrode part 23b from the outside of the housing main body 20b (housing 2b) unintentionally.
Further, by energizing the electrode portion 23b, a potential difference is generated between the electrode portion 23b and the substrate 3b, and a Coulomb force is generated. Thereby, the board | substrate 3b can be displaced to the thickness direction. As a result, the above-described substrate 3a and substrate 3b can be displaced so as to approach and separate from each other, and thereby the above-described reflective film 312a and reflective film 312b can be displaced so as to approach and separate from each other.

In other words, the first and second substrates 3a and 3b (a pair of first substrates) and the electrode part 23a and the electrode part 23b (a pair of first electrode parts) displace the reflecting film 312a and the reflecting film 312b. Displacement means is configured.
In other words, the reflective film 312a, the substrate 3a, and the electrode part 23a accommodated in the recess 21a, and the reflective film 312b, the substrate 3b, and the electrode part 23b accommodated in the recess 21b constitute first displacement means.

In the present embodiment, the first displacing means displaces the reflective film 312a and the reflective film 312b by the action of the Coulomb force as described above, but is not limited to this in the optical device of the present invention. That is, the first displacing means may be displaced by a force other than the Coulomb force, for example, an action such as a reverse piezoelectric effect.
Similar to the electrode portion 23a, the electrode portion 23b includes an electrode plate 233 having an annular shape (ring shape).

The electrode part 23b (electrode plate 233) faces the edge part 31 of the substrate 3b (see FIG. 1). Moreover, although illustration is abbreviate | omitted, the edge part 31 of the board | substrate 3b is included in the electrode plate 233 by planar view.
By providing such an electrode portion 23b, when the electrode portion 23b is energized, the substrate 3b can be stably driven (displaced) in the vertical direction, that is, in the thickness direction of the substrate 3b.

The electrode part 23b is made of a conductive material. Although it does not specifically limit as this material, For example, the material which was mentioned by description of the electrode part 23a can be used.
The thickness (average) of the electrode part 23b is appropriately selected depending on the constituent material, application, etc., and is not particularly limited, but is preferably about 0.01 to 20 μm, more preferably 1 to 3 μm. preferable.

Further, as shown in FIG. 1, it is preferable that antireflection films 311b and 210b are formed in the recess 21b.
The antireflection film 311b has substantially the same shape as the reflection film 312b. The antireflection film 311b is provided concentrically with the substrate 3b (reflection film 312b), on the surface opposite to the upper surface of the substrate 3b on which the reflection film 312b is formed, that is, on the lower surface.

The antireflection film 210b has substantially the same shape as the antireflection film 311b. The antireflection film 210b is provided on the bottom 211 of the recess 21b so as to face the antireflection film 311b, that is, to overlap the antireflection film 311b in a plan view.
By forming such antireflection films 311b and 210b, reflection of external light incident on the optical device 1 and interference light interfering between the reflection film 312b and the reflection film 312b is suppressed, and light is transmitted. It can be transmitted efficiently.

Further, each of the antireflection films 311b and 210b is formed of a multilayer film. As a constituent material of the multilayer film, for example, materials described in the description of the antireflection films 311a and 210a can be used.
In addition, it is preferable that at least one of the antireflection films 311b and 210b has an insulating property. Thereby, the short circuit (short circuit) with the electrode part 23b and the board | substrate 3b can be prevented.

The structure 10 </ b> A (housing 2 a) and the structure 10 </ b> B (housing 2 b) configured as described above are joined via the spacer 11.
The spacer 11 is preferably made of the same material as that of the housing body 20a (20b) or silicon. Furthermore, the spacer 11 is interposed between the silicon layer 33 of the housing 2b and the silicon layer 33 of the housing 2b, and is preferably in direct contact with and bonded to both the silicon layers 33. When such a spacer 11 is comprised with the above materials, these can be firmly and directly joined by performing various processes, making the spacer 11 and structure 10A, 10B contact directly. .

As such a spacer 11, one having a high smoothness of the surface contributing to the joining (surface roughness is small) is preferable.
Specifically, the surface roughness Ra of the bonding surface is preferably 50 nm or less, and preferably 20 nm or less. Thereby, although it depends on the smoothness of the silicon layer 33, bonding can be performed even at a relatively low temperature. In addition, it is possible to more reliably prevent the occurrence of variations in bonding strength, voids, and the like at the bonding interface.

  For example, when the spacer 11 and the structures 10A and 10B are bonded (adhered) using an adhesive, the reflective film 312a (substrate 3a) and the reflective film are reflected due to a change in volume of the adhesive accompanying a temperature change. The distance h1 between the film 312b (substrate 3b) changes. For this reason, there is a possibility of affecting the wavelength separation. Furthermore, when the adhesive is not supplied uniformly, the thickness of the adhesive after curing becomes non-uniform, and the parallelism between the reflective film 312a and the reflective film 312b may be reduced.

From this point of view, in the optical device 1 of the present invention, it is preferable to join the spacer 11 and the structures 10A and 10B directly, that is, without using an adhesive, as described above. Thereby, the space | interval h1 can be maintained constant and the fall of the parallelism of the reflecting film 312a and the reflecting film 312b can be prevented. As a result, wavelength separation can be reliably performed.
The spacer 11 has a frame shape, and the height of the space defined by the structures 10A and 10B and the spacer 11 is adjusted by changing the thickness thereof, so that the substrate 3a and the substrate 3b are structured respectively. The range (displacement width) that can be displaced without contacting the body 10A and the structure 10B can be easily adjusted.
The thickness of the spacer 11 is appropriately selected depending on the constituent material of the spacer 11, the use of the optical device 1, etc., and is not particularly limited, but is preferably about 0.1 to 100 μm.

On the other hand, the structure 10C in the second structure U2 includes a housing 2c, a substrate 3c that can be accommodated in the housing 2c, a reflective film 312c provided on the lower surface (one surface) of the substrate 3c, and the substrate 3c. And an electrode portion 23c to be displaced.
As shown in FIG. 1, the structure 10D in the second structure U2 is provided on the housing 2d, the substrate 3d that can be accommodated in the housing 2d, and the upper surface of the substrate 3d (surface on the substrate 3c side). The reflective film 312d and the electrode part 23d for displacing the substrate 3d are provided.

That is, the substrate 3c and the substrate 3d (a pair of second substrates), and the electrode unit 23c and the electrode unit 23d (a pair of second electrode units) are used to displace the reflective film 312c and the reflective film 312d. Displacement means is configured.
In other words, the reflective film 312c, the substrate 3c, and the electrode part 23c accommodated in the recess 21c, and the reflective film 312d, the substrate 3d, and the electrode part 23d accommodated in the recess 21d constitute second displacement means.

Further, as shown in FIG. 1, it is preferable that an antireflection film 100d is provided on the lower surface of the housing body 20d. Thereby, reflection of external light incident on the optical device 1 can be suppressed.
Note that the antireflection film 100d is preferably formed of a multilayer film, similarly to the antireflection films 311b and 210b.

In the present embodiment, the second displacing means displaces the reflective film 312c and the reflective film 312d by the action of the Coulomb force as described above, but the present invention is not limited to this. That is, the second displacing means may be displaced by a force other than the Coulomb force, for example, an action such as a reverse piezoelectric effect.
Note that the structure 10C and the structure 10D have the same configurations as the structure 10A and the structure 10B described above, respectively, and thus detailed description thereof is omitted.

The optical device 1 of the present embodiment includes a first structure U1 having such structures 10A and 10B and the spacer 11, and a second structure U2 having the structures 10C and 10D and the spacer 11. It is formed by bonding through the intermediate layer 4.
The intermediate layer 4 is interposed between the first structural body U1 and the second structural body U2, and has a function of optically bonding the two or improving the bonding strength between the two. .

Such an intermediate layer 4 is preferably composed of various adhesives, for example. Thereby, the 1st structure U1 and the 2nd structure U2 can be adhered more firmly.
As this adhesive, various adhesives having curability such as a hot melt type, a thermosetting type, and a photocurable type can be used.
Further, as the intermediate layer 4, in addition to the above-described antireflection film, the refractive index of the intermediate layer 4 is such that the refractive index of the portion through which the light of the first structure U1 transmits and the light of the second structure U2 It is preferable that the refractive index of the transmitted portion is substantially equal. Thereby, when light permeate | transmits the interface of 1st structure U1 and intermediate | middle layer 4, and the interface of intermediate | middle layer 4 and 2nd structure U2, unintentional reflection of light can be suppressed. . As a result, the first structural body U1 and the second structural body U2 can be optically bonded, and the light loss of the optical device 1 can be reduced.

As described above, as the intermediate layer 4 having a refractive index substantially equal to each of the structures U1 and U2, for example, various index matching materials and the like are preferably used.
Moreover, although the average thickness of the intermediate | middle layer 4 is not specifically limited, It is preferable that it is about 0.1-300 micrometers, and it is more preferable that it is about 1-200 micrometers.
In the optical device 1 having such a configuration, the distance h1 between the reflective film 312a and the reflective film 312b in the first structure U1 and the distance h2 between the reflective film 312a and the reflective film 312b in the second structure U2. Both can be changed as appropriate. In the state where the changed intervals h1 and h2 are maintained, the incident light L1 is repeatedly reflected between the reflection film 312a and the reflection film 312b of the first structure U1 to cause interference, and the interval h1 is set. The light L2 having the corresponding wavelength is emitted toward the adjacent second structural body U2. The light L2 incident on the second structural body U2 is repeatedly reflected between the reflective film 312a and the reflective film 312b of the second structural body U2, causing interference, and the light L3 having a wavelength corresponding to the interval h2. Can be emitted to the outside. At this time, in order to change the intervals h1 and h2, there are the following three cases (patterns) in the first structures U1 and U2, respectively. Since the first structure U1 and the second structure U2 have the same configuration, the first structure U1 will be described below as a representative, and the second structure U2 will be described. Is omitted.

(1) The case where the substrate 3a is displaced preferentially without the substrate 3b being displaced in principle.
(2) When the substrate 3b is displaced preferentially without the substrate 3a being displaced in principle. That is, the pattern is the reverse of pattern (1).
(3) When both substrate 3a and substrate 3b are displaced. That is, the substrate 3a and the substrate 3b are displaced in a mirror image manner. For example, when the substrate 3a is displaced by 1 toward the substrate 3b, the substrate 3b is similarly displaced by 1 toward the substrate 3a.

  For example, in a conventional optical device (wavelength variable filter) having a movable reflective film that is movable (displaced) by the operation of the drive unit (electrode part) and a fixed reflective film that is fixedly installed, the movable reflective film and the fixed reflective film As the distance from the film decreases, the Coulomb force (suction force) between the movable reflective film and the fixed reflective film increases, and eventually exceeds the Coulomb force controlled by the drive unit. As a result, the movable reflective film and the fixed reflective film are in close contact with each other, that is, no gap is formed between the movable reflective film and the fixed reflective film, and wavelength separation cannot be performed.

  However, in the optical device 1 of the present invention, even when the interval h1 is set small, for example, in the case of the pattern (3) (the same applies to the patterns (1) and (2)), the reflective film 312a and the reflective film 312b The Coulomb force does not reach the Coulomb force controlled by the electrode part 23a and the electrode part 23b, so that the reflective film 312a and the reflective film 312b are reliably prevented from coming into close contact with each other. Thus, wavelength separation can be reliably performed not only when the interval h1 is set large, but also when the interval h1 is set small.

In the conventional optical device, for example, when the movable reflective film is moved by 10 μm, in the optical device 1 of the present invention, when the pattern (3), the reflective film 312a and the reflective film 312b are each moved by 5 μm. Good.
As described above, in the optical device 1 of the present invention, the movable range (movement distance) of the substrate 3a is reduced, so that the Coulomb force between the electrode portion 23a and the substrate 3a can be reliably maintained. The same applies to the substrate 3b.

Further, in the optical device 1, since the movable range of the substrate 3a is small, the magnitude of the voltage applied to the electrode portion 23a can be set smaller than the magnitude of the voltage applied to the electrode portion of the conventional optical device. it can. Therefore, it contributes to energy saving. The same applies to the electrode portion 23b.
Moreover, in the optical device 1, since the movable range of the board | substrate 3a becomes small, the responsiveness which changes the space | interval h1 can be improved, ie, the time (response time) for changing the space | interval h1 can be shortened. it can. In the above example, the response time of the optical device 1 is half of the response time of the conventional optical device.

  Further, as shown in the patterns (1) and (2), in the optical device 1, the substrate 3a and the substrate 3b can be displaced independently of each other by the energization pattern of the electrode portion 23a and the electrode portion 23b. Thereby, the movable range of the board | substrate 3a and the board | substrate 3b can be set largely, Therefore Wavelength separation can be more reliably performed with respect to the light which has various wavelengths.

Next, an operation when the optical device 1 performs wavelength separation will be described.
As shown in FIG. 1, the light L <b> 1 emitted from the light source 400 is incident on the first structure U <b> 1 of the optical device 1. That is, the light L1 sequentially passes through the antireflection film 100a, the housing body 20a, the antireflection film 210a, the antireflection film 311a, the substrate 3a, and the reflection film 312a and enters the gap 25.

The light L1 incident on the gap 25 is repeatedly reflected between the reflective film 312a and the reflective film 312b whose interval h1 is set to a predetermined size, and causes interference. At this time, the loss of the light L1 can be suppressed by the reflective film 312a and the reflective film 312b.
As a result of the interference of the light L1, light (interference light) L2 having a wavelength corresponding to the interval h1 is sequentially transmitted through the substrate 3b, the antireflection film 311b, the antireflection film 210b, and the housing body 20b, and the first structure U1. Is emitted toward the intermediate layer 4.

Thereafter, the light L2 transmitted through the intermediate layer 4 is incident on the adjacent second structural body U2. That is, the light L2 sequentially passes through the housing body 20c, the antireflection film 210c, the antireflection film 311c, the substrate 3c, and the reflection film 312c, and enters the gap 25.
The light L2 that has entered the gap 25 is repeatedly reflected between the reflective film 312c and the reflective film 312d whose interval h2 is set to a predetermined size, thereby causing interference. At this time, the loss of the light L2 can be suppressed by the reflective film 312c and the reflective film 312d.

As a result of the interference of the light L2, light (interference light) L3 having a wavelength corresponding to the interval h2 sequentially passes through the substrate 3d, the antireflection film 311d, the antireflection film 210d, the housing body 20d, and the antireflection film 100d. The light is emitted from the second structural body U2 (optical device 1).
As described above, according to the optical device 1, both the interval h1 and the interval h2 can be appropriately changed to a desired size, thereby ensuring wavelength separation for light having various wavelengths. Can be done.

Here, the wavelength separation will be described more specifically.
FIG. 3 is a diagram illustrating the wavelength distribution of each of the lights L1, L2, and L3. 3A to 3C, the horizontal axis represents wavelength, and the vertical axis represents transmittance.
First, it is assumed that the light L1 has a substantially flat wavelength distribution as shown in FIG.
Here, the interval h1 in the first structure U1 is set so that the light incident on the first structure U1 is separated into a specific wavelength region of the transmittance peak interval FSR1.

Next, the interval h2 in the second structure U2 is set so that the light incident on the second structure U2 is separated into a specific wavelength range of the transmittance peak interval FSR2. At this time, for example, the setting is performed by setting the interval h2 larger than the interval h1 so that the FSR2 becomes smaller than the FSR1.
When the light L1 is incident on the first structure U1, the light L1 is wavelength-separated according to the interval h1, and light L2 having a wavelength distribution with a peak interval FSR1 indicated by a solid line in FIG. 3B can be obtained. . At this time, the light other than the light L2 is attenuated in the first structure U1 because its wavelength does not match the transmission condition determined by the interval h1 of the first structure U1.

Next, when the light L2 is incident on the second structure U2, the light L2 is wavelength-separated according to the interval h2, and light L3 having a wavelength distribution with a peak interval FSR2 indicated by a solid line in FIG. 3C can be obtained. . In this case, for example, when the first structure U1 is the peak wavelength of light that can penetrate the peak wavelength of the second light structure U2 may be transmitted to the match at the wavelength lambda _0, the wavelength lambda ₀ Since the wavelength of the light other than the peak does not match the transmission condition determined by the interval h2 of the second structure U2, the light is attenuated and removed in the second structure U2.

  That is, in the optical device 1, by setting the interval h1 and the interval h2 to be different, the wavelength range of the light transmitted by the first structure U1 and the wavelength range of the light transmitted by the second structure U2 Can be different. Accordingly, the light transmission condition of the optical device 1 can be a combination of the light transmission condition of the first structure U1 and the light transmission condition of the second structure U2.

In other words, the first structure U1 and the second structure U2 may transmit only light in a specific wavelength region set in both the interval h1 and the interval h2 out of the incident light L1. it can. At this time, the first structural body U1 and the second structural body U2 can share and attenuate the wavelength range of the attenuated / removed light.
Thereby, wavelength separation can be performed in two stages in the first structure body U1 and the second structure body U2, and wavelength separation with a higher degree of freedom is possible.

  Next, a method for manufacturing the optical device 1 will be described with reference to FIGS. In the following, the structural members such as the housing main bodies 20a, 20b, 20c, 20d, the substrates 3a, 3b, 3c, 3d, and the spacer 11 are formed in a state where a plurality of them are connected in the horizontal direction. It is explained by using an aggregate. Here, the aggregate refers to, for example, a glass wafer, a silicon wafer, or the like formed by a plurality of the above-described constituent members. However, FIGS. 4 to 7 show only one optical device.

  [1] First, prior to the manufacture of the optical device 1, a transparent substrate (a substrate having optical transparency) 5 is prepared. For the transparent substrate 5, a glass wafer having a uniform thickness and free from deflection and scratches is preferably used. The material of the transparent substrate 5 is as described in the description of the housing body. In particular, since the transparent substrate 5 may be heated at the time of bonding, a material having a thermal expansion coefficient substantially equal to the upper Si layer 73 described later is preferably selected from the viewpoint of preventing the transparent substrate 5 from being distorted by thermal stress. Is done.

[2] Next, as shown in FIG. 4A, a mask layer 6 is formed (masked) on the upper surface of the transparent substrate 5.
Examples of the material constituting the mask layer 6 include metals such as Au / Cr, Au / Ti, Pt / Cr, and Pt / Ti, silicon such as polycrystalline silicon (polysilicon) and amorphous silicon, and silicon nitride. It is done. When silicon is used for the mask layer 6, adhesion between the mask layer 6 and the transparent substrate 5 is improved. When a metal is used for the mask layer 6, the visibility of the formed mask layer 6 is improved.

The thickness of the mask layer 6 is not particularly limited, but is preferably about 0.01 to 1 μm, and more preferably about 0.09 to 0.11 μm. If the mask layer 6 is too thin, the transparent substrate 5 may not be sufficiently protected. If the mask layer 6 is too thick, the mask layer 6 may be easily peeled off due to internal stress of the mask layer 6.
The mask layer 6 can be formed by, for example, a chemical vapor deposition method (CVD method), a sputtering method, a vapor deposition method such as a vapor deposition method, a plating method, or the like.

[3] Next, as shown in FIG. 4B, an opening 61 is formed in the mask layer 6.
The opening 61 is provided, for example, at a position where the recess 21b is formed. The shape (planar shape) of the opening 61 corresponds to the shape (planar shape) of the recess 21b to be formed.
The opening 61 can be formed by, for example, a photolithography method. Specifically, first, a resist layer (not shown) having a pattern corresponding to the opening 61 is formed on the mask layer 6. Next, a part of the mask layer 6 is removed using the resist layer as a mask. Next, the resist layer is removed. Thereby, the opening 61 is formed. The mask layer 6 can be partially removed by, for example, dry etching using CF gas, chlorine-based gas, or the like, or immersion in a stripping solution such as hydrofluoric acid + nitric acid aqueous solution or alkaline aqueous solution (wet etching).

[4] Next, as shown in FIG. 4C, a recess 21 d is formed in the transparent substrate 5.
Examples of the method for forming the recess 21d include an etching method such as a dry etching method and a wet etching method. For example, by performing etching, the transparent substrate 5 is etched isotropically from the opening 61 to form a cylindrical concave portion 21d.
In particular, according to the wet etching method, it is possible to form the concave portion 21d close to an ideal cylindrical shape. For example, a hydrofluoric acid-based etchant is preferably used as an etchant for wet etching. At this time, when an alcohol (particularly a polyhydric alcohol) such as glycerin is added to the etching solution, the surface of the recess 21d becomes extremely smooth.

[5] Next, the mask layer 6 is removed.
For example, this can be performed by immersion (wet etching) in a stripping solution (removal solution) such as an alkaline aqueous solution (eg, tetramethylammonium hydroxide aqueous solution), hydrochloric acid + nitric acid aqueous solution, hydrofluoric acid + nitric acid aqueous solution, CF gas, chlorine-based gas It can be performed by dry etching or the like.
In particular, when the mask layer 6 is removed by immersing the transparent substrate 5 in a removing solution, the mask layer 6 can be efficiently removed by a simple operation.
As described above, as shown in FIG. 4D, the concave portion 21d is formed in the transparent substrate 5 at a predetermined position.

[6] Next, as shown in FIG. 5E, an electrode portion 23d is formed on the bottom 211 of the recess 21d.
Examples of the material constituting the electrode portion 23d include metals such as Cr, Al, Al alloys, Ni, Zn, and Ti, resins in which carbon and titanium are dispersed, silicon such as polycrystalline silicon (polysilicon) and amorphous silicon, Examples thereof include transparent conductive materials such as silicon nitride and ITO.

The thickness of the electrode portion 23d is preferably 0.1 to 0.2 μm, for example.
The electrode portion 23d can be formed of a transparent conductive material layer formed by vapor deposition, sputtering, ion plating, or the like. Further, unnecessary portions may be removed by combining the photolithography method with such a method. Specifically, first, a resist layer (not shown) having a pattern corresponding to the electrode portion 23d is formed. Examples of the material constituting the resist layer include Cr / Au / Cr.
Next, a part of the transparent conductive material layer is removed using the resist layer as a mask. Thereby, the electrode part 23d is formed.

[7] Next, as shown in FIG. 5 (f), an antireflection film 210 d is provided on the bottom 211 of the recess 21 d, and an antireflection film 100 d is provided on the lower surface of the transparent substrate 5.
In this manufacturing process, the antireflection films 210d and 100d are formed of multilayer films.
Examples of the material constituting the multilayer film include SiO ₂ , Ta ₂ O ₅ , SiN, and the like.

By laminating these layers alternately, a multilayer film having a predetermined thickness can be provided.
The thickness of each of the antireflection films 210d and 100d is preferably, for example, 0.1 to 12 μm.
Thus, the housing 2d ′ for the optical device 1 in which the concave portion 21d, the electrode portion 23d, and the antireflection films 210d and 100d are formed at predetermined positions on the transparent substrate 5 is obtained. The housing 2d ′ has a configuration in which the silicon layer 33 and the support portion 22 are omitted from the housing 2b.

Hereinafter, using the wafer, the method for manufacturing the substrate 3d, the support portion 32, and the silicon layer 33, the manufactured substrate 3d (including the support portion 32 and the silicon layer 33), and the housing 2d for the optical device 1 are used. A method for manufacturing the optical device 1 will be described.
When the substrate 3d is manufactured, a silicon wafer (hereinafter simply referred to as “wafer”) 7 is first prepared. The wafer 7 can be manufactured and prepared as follows, for example.
The wafer 7 preferably has a characteristic that the surface can be mirror-finished from the viewpoint of the surface roughness described above.
For this reason, as the wafer 7, for example, an SOI (Silicon on Insulator) substrate, an SOS (Silicon on Sapphire) substrate, a silicon substrate, or the like can be used.

In this manufacturing process, an SOI substrate is used as the wafer 7.
The wafer 7 is composed of a three-layered structure including an Si base layer 71, an SiO ₂ layer 72, and an upper Si layer (active layer) 73.
The thickness of the wafer 7 is not particularly limited, but the upper Si layer 73 is particularly preferably about 10 to 100 μm.

[8] First, as shown in FIG. 5G, an antireflection film 311d is provided on the lower surface of the upper Si layer 73 so as to face the recess 21d after the bonding step described later.
[9] Next, as shown in FIG. 5H, the upper Si layer 73 of the wafer 7 and the surface of the housing 2d ′ on which the recess 21d is formed face each other so that the wafer 7 is in direct contact with the housing. Place on 2d '. And a contact part is joined.

This bonding can be performed by a bonding method such as anodic bonding or fusion welding, but is preferably performed by anodic bonding. In anodic bonding, since it is not necessary to melt the object to be bonded, bonding can be performed at a relatively low temperature. Thereby, deterioration and deformation of the member due to heat can be prevented.
Such anodic bonding is performed as follows, for example.

[9-1] First, a negative terminal of a DC power source (not shown) is connected to the housing 2 d ′, and a positive terminal of a DC power source (not shown) is connected to the upper Si layer 73.
[9-2] Next, a voltage is applied while heating the housing 2d ′. This heating facilitates movement of movable ions such as Na ⁺ (sodium ions) in the housing 2d ′. Due to the movement of Na ⁺ , the bonding surface of the housing 2d ′ is negatively charged, and the bonding surface of the wafer 7 is positively charged. As a result, the housing 2d ′ and the wafer 7 are firmly bonded.

At this time, the applied voltage is preferably about 200 to 2000V, and more preferably about 500 to 1000V. When the voltage is within the above range, the anodic bonding between the housing 2d ′ and the wafer 7 is performed more reliably and more firmly.
The heating temperature is not particularly limited as long as the anodic bonding between the housing 2d ′ and the wafer 7 is performed, but is preferably about 200 to 500 ° C., more preferably about 300 to 400 ° C. As a result, the anodic bonding between the housing 2d ′ and the wafer 7 is more reliably and firmly performed. Even at such a relatively low temperature, the bonding can be performed while preventing deterioration or deformation of the housing 2d ′ and the wafer 7 due to heat.

[10] Next, as shown in FIG. 6 (i), the Si base layer 71 is removed by etching and polishing.
As the etching method, for example, wet etching or dry etching is used, but dry etching is preferably used. In any case, when the Si base layer 71 is removed, the SiO ₂ layer 72 serves as a stopper. However, since the dry etching does not use an etchant, the upper Si layer 73 facing the electrode portion 23b is damaged. It can prevent suitably. Thereby, the optical device 1 can be manufactured with a high yield.

[11] Next, as shown in FIG. 6J, etching is performed to remove the SiO ₂ layer 72. When etching is performed, an etchant containing hydrofluoric acid is preferably used. Thereby, the SiO ₂ layer 72 can be suitably removed, and the upper Si layer 73 can be suitably formed.
In the case where the wafer 7 is formed of Si alone and has an optimum thickness for performing the subsequent steps, the steps [10] and [11] may not be performed. Thereby, the process at the time of manufacturing the optical device 1 can be simplified.

[12] Next, as shown in FIG. 6 (k), a reflective film 312 d is provided at a location corresponding to the antireflection film 311 d on the upper surface of the upper Si layer 73.
[13] Next, a resist layer (not shown) having a pattern corresponding to the shape (planar shape) of the substrate 3d and the support portion 32 is formed. Next, as shown in FIG. 6L, the upper Si layer 73 is etched by a dry etching method, particularly ICP etching, to form a through hole 8. Thus, the substrate 3d, the support portion 32, and the silicon layer 33 are integrally formed.

In this step, ICP etching is performed. That is, the substrate 3d is formed by alternately repeating the etching with the etching gas and the formation of the protective film with the deposition gas.
Examples of the etching gas include SF _{6 and the} like, and examples of the deposition gas include C ₄ F _{8 and the} like.

As a result, only the upper Si layer 73 is etched, and since it is dry etching, the substrate 3d, the support portion 32, and the silicon layer 33 are accurately and reliably formed without affecting other portions. Can do.
As described above, since the dry etching method, particularly ICP etching is used in forming the substrate 3d, the support portion 32, and the silicon layer 33, the substrate 3d can be formed easily, reliably, and accurately.
In the present invention, in this step, the substrate 3d, the support portion 32, and the silicon layer 33 may be formed by using a dry etching method different from the above, or by using a method other than the dry etching method. The substrate 3d, the support portion 32, and the silicon layer 33 may be formed.

As described above, the structure 10D for the optical device 1 is obtained.
Moreover, the structural bodies 10C, 10B, and 10A for the optical device 1 can be manufactured through substantially the same steps as the steps [1] to [13].
In the structures 10C and 10B, an antireflection film similar to the antireflection film 100d of the structure 10D may be provided as necessary and may be omitted.

[14] Next, as shown in FIG. 6M, the frame-shaped spacer 11 is bonded to the silicon layer 33 on the structure 10D. This bonding can be performed by, for example, anodic bonding or direct bonding.
Among these, anodic bonding is suitably used when the constituent material of the spacer 11 is glass containing movable ions such as alkali metal.
On the other hand, the direct bonding is suitably used when the constituent material of the spacer 11 is silicon.
Hereinafter, anodic bonding and direct bonding will be sequentially described.

<< Anodic bonding >>
[14-1A] First, the structure 10D and the spacer 11 are arranged so that the spacer 11 directly contacts the silicon layer 33.
[14-2A] Next, a negative terminal of a DC power source (not shown) is connected to the upper portion of the spacer 11, and a positive terminal of a DC power source (not shown) is connected to the lower portion of the silicon layer 33. Then, a voltage is applied while heating the spacer 11. Thereby, movable ions such as Na ^{+ in} the spacer 11 are easily moved according to the electric field. By this movement of Na ⁺ , the upper surface and the lower surface of the spacer 11 are negatively charged. On the other hand, the bonding surface of the silicon layer 33 is positively charged. As a result, a strong electrostatic attractive force is generated and adsorbed between the spacer 11 and the silicon layer 33, and a strong bond due to a chemical bond such as a covalent bond is formed.
At this time, the voltage to be applied and the heating temperature are the same as in step [9-2].

Further, as described above, by using anodic bonding, the spacer 11 and the silicon layer 33 can be firmly bonded even at a relatively low temperature. Thereby, deterioration or deformation | transformation by the heat | fever of the spacer 11 and the silicon layer 33 grade can be prevented.
Furthermore, according to anodic bonding, the spacer 11 and the silicon layer 33 can be hermetically bonded. As a result, the optical device 1 of the present embodiment is hermetically sealed, and can prevent (improve weather resistance) deterioration or contamination due to the external environment of optical components such as a reflection film and an antireflection film inside the optical device 1. .

  Conventionally, in order to protect such an optical device from the external environment, the entire optical device has been sealed in an airtight package. However, in the optical device 1 of the present invention, as described above, since the optical device 1 itself has resistance to the external environment, an airtight package can be omitted. Thereby, reduction of the manufacturing cost of the optical device 1, simplification of a manufacturing process, etc. are achieved.

<< Direct bonding >>
[14-1B] First, surface oxidation treatment is performed on at least one of the bonding surface of the spacer 11 and the bonding surface of the silicon layer 33. Thereby, the bonding surface of the silicon spacer 11 and the bonding surface of the silicon layer 33 are oxidized, and silicon oxide (SiO ₂ ) is generated on each bonding surface. As a result, a large number of hydroxyl groups are generated on each bonding surface, and bonding due to hydrogen bonding occurs between the bonding surfaces.

Examples of the surface oxidation treatment include oxygen plasma treatment, ultraviolet irradiation treatment, dry process treatment such as ion irradiation treatment, wet process treatment such as acid treatment, and the like.
Among these, at least one of oxygen plasma treatment and acid treatment is preferable. Thereby, the silicon | silicone of the said joint surface can be oxidized more efficiently.
The oxygen plasma treatment is a treatment for generating a hydroxyl group on the joint surface by bringing the joint surface into contact with active oxygen generated by plasma.
As an example of the conditions for the oxygen plasma treatment, the plasma output is about 50 to 1000 W, the oxygen gas flow rate is about 50 to 100 mL / min, and the treatment temperature is about 30 to 90 ° C.

On the other hand, the acid treatment is a treatment for oxidizing the joint surface by bringing a chemical solution containing an acid into contact with the joint surface.
Examples of the acid include sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl), and the like.
In addition to the acid, the chemical solution includes, for example, various kinds of water such as hydrogen peroxide (H ₂ O ₂ ), distilled water, pure water, ultrapure water, ion exchange water, RO water, and the like. Also good.
Furthermore, when the chemical solution is brought into contact with the bonding surface, the chemical solution may be heated to a boiling level or may be performed while irradiating the chemical solution with ultrasonic waves. Thereby, surface oxidation treatment can be performed more efficiently.

[14-2B] Next, the structure 10D and the spacer 11 are arranged so that the joint surface on which the surface oxidation treatment is performed on the silicon layer 33 is in direct contact with the joint surface on which the spacer 11 is subjected to the surface oxidation treatment. .
[14-3B] Next, the arranged structure 10D and the spacer 11 are heated. Thereby, the bond by the hydrogen bond changes to a Si—O—Si bond, and the silicon layer 33 and the spacer 11 are directly bonded (silicon fusion bonding). As a result, the silicon layer and the spacer 11 are firmly bonded.

At this time, the heating temperature is preferably about 30 to 500 ° C, more preferably about 300 to 400 ° C. Thereby, it can join more firmly, minimizing the influence of the heat | fever to a joining target object.
Further, during heating, a compressive force may be applied in a direction in which the spacer 11 and the silicon layer 33 are brought close to each other. Thereby, it can join more firmly and evenly.

In addition, according to the direct bonding, since the spacer 11 and the silicon layer 33 can be hermetically bonded as in the case of the anodic bonding, the weather resistance of the optical device 1 can be improved, the manufacturing cost can be reduced, and the manufacturing process can be performed. Can be simplified.
Further, when direct bonding is used, the spacer 11 is made of silicon. For this reason, the difference in thermal expansion coefficient between the spacer 11 and the silicon layer 33 is almost eliminated, and generation of thermal stress due to the difference in thermal expansion between the spacer 11 and the silicon layer 33 can be prevented. As a result, it is possible to reliably prevent damage to the joint due to thermal stress, deformation of the optical device 1, deterioration of device characteristics due to them, and the like, and obtain a high-quality optical device 1.
Further, even when the optical device 1 is downsized and the allowable range of deformation is inevitably reduced, the deformation of the optical device 1 is prevented by using direct bonding, so that the characteristics of the optical device 1 are deteriorated. The size can be reduced while preventing.

[15] Next, as shown in FIG. 7 (n), a frame-shaped spacer 11 is bonded onto the silicon layer 33 of the structure 10 </ b> D so that the substrate 3 c and the substrate 3 d face each other. This joining can be performed, for example, by the same method as in the step [14].
Further, this bonding is preferably performed in a reduced pressure atmosphere. Thereby, the optical device 1 in a state where the space defined by the structures 10C and 10D and the spacer 11 is decompressed can be obtained. As a result, it is possible to reduce the air resistance when the substrate 3c and the substrate 3d disposed in the optical device 1 are displaced, and to suppress deterioration with time of optical components such as a reflection film and an antireflection film. That is, the optical device 1 with high reliability can be obtained.

In addition, although this embodiment demonstrated the case where the said process [14] and the said process [15] were performed separately, these can also be performed simultaneously. That is, the spacer 11 is disposed on the silicon layer 33 of the structure 10D so as to be in direct contact, and further, the silicon layer 33 of the structure 10C is disposed so as to be in direct contact with the spacer 11. These are bonded together by anodic bonding or direct bonding. According to such a method, the manufacturing process can be simplified.
Thus, the second structure U2 for the optical device 1 is obtained.
Moreover, the 1st structure U1 for optical devices 1 can be manufactured by passing through the process substantially the same as said process [14]-[15].

[16] Next, as shown in FIG. 7 (o), the first structure U1 is stacked (joined) on the second structure U2. At this time, the first structure body U1 and the second structure body U2 are stacked via the intermediate layer 4 along the optical axis of the incident light. Hereinafter, a method of laminating the first structure body U1 and the second structure body U2 via a sheet-like intermediate layer will be described as a representative.
[16-1] First, a sheet-like intermediate layer is overlaid on the housing 2c of the second structure U2.
[16-2] Next, the first structure U1 and the second structure U2 are arranged so that the lower surface of the housing 2b of the first structure U1 is in contact with the intermediate layer. Thereby, the gap between the upper surface of the housing 2c and the lower surface of the housing 2b can be filled with the intermediate layer.
The assembly of the optical device 1 is obtained through the above steps.

[17] Next, a plurality of optical devices 1 are taken out by dividing the aggregate of the optical devices 1. As a result, it is possible to improve the yield while preventing an increase in time required for manufacturing the optical device 1. As a result, the manufacturing cost of the optical device 1 can be reduced.
Moreover, since a plurality are manufactured in a lump, variation in characteristics between the optical devices 1 can be suppressed.

The method for dividing the assembly of the optical device 1 is not particularly limited, and examples thereof include various methods such as machining such as dicing saw and wire saw, laser processing, water jet processing, cleaving due to impact, and etching.
Further, as in the present embodiment, when the space defined by the structures 10A and 10B and the spacer 11 of the optical device 1 and the space defined by the structures 10C and 10D and the spacer 11 are sealed In the above-described division processing, it is possible to prevent deterioration of the characteristics of the optical device 1 due to the entry of unnecessary materials such as water and chips into the space.

By adding the steps as described above, one optical device 1 is obtained.
In addition, although this embodiment demonstrated the case where the some optical device 1 was manufactured collectively, the manufacturing method of the optical device of this invention is not limited to such a case. That is, when manufacturing one optical device 1, it goes without saying that the method for manufacturing an optical device of the present invention is applicable.

Second Embodiment
8 is a cross-sectional view (side view) showing a second embodiment of the optical device of the present invention, and FIG. 9 is a cross-sectional view (plan view) taken along the line BB of the optical device shown in FIG. In the following description, the upper side in FIG. 8 is referred to as “upper” and the lower side is referred to as “lower”.
Hereinafter, the second embodiment of the optical device of the present invention will be described with reference to these drawings. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

The optical device 1 of the present embodiment is the same as the optical device 1 of the first embodiment except that the configurations of the electrode portions 23e, 23f, 23g, and 23h are different.
As shown in FIGS. 8 and 9, the electrode portion 23 e of the optical device 1 </ b> A includes two (a pair of) electrode plates 231 and 232. The electrode plates 231 and 232 can be energized independently.

The electrode plates 231 and 232 are provided to face the edge 31 of the substrate 3a.
Such electrode plates 231 and 232 change the shape of the resist layer serving as a mask when the second electrode portion 23d is formed on the bottom 211 of the recess 21d in the manufacturing process [6] of the first embodiment. Can be formed.
Similarly to the above method, the electrode portions 23f, 23g, and 23h constituted by the two electrode plates 231 and 232 can be formed.

Thus, in the electrode part 23e comprised by the two electrode plates 231 and 232, by supplying with electricity to the electrode plate 231, the board | substrate 3a will incline to the electrode plate 231 side (refer FIG. 8). On the other hand, when the electrode plate 232 is energized, the substrate 3a is inclined toward the electrode plate 232 side.
In addition, by energizing both the electrode plates 231 and 232 of the electrode portion 23e, the substrate 3a can be displaced in the vertical direction as in the first embodiment.
Thus, by changing the energization pattern of the electrode part 23e, the posture of the substrate 3a can be easily and reliably changed.

As shown in FIG. 8, the electrode part 23f of the optical device 1A is composed of two electrode plates 231 and 232 in substantially the same manner as the electrode part 23e. The electrode plates 231 and 232 can be energized independently. The electrode plates 231 and 232 are provided to face the edge 31 of the substrate 3b.
In the electrode part 23f having such a configuration, when the electrode plate 231 is energized, the substrate 3b is inclined toward the electrode plate 231 side. On the other hand, when the electrode plate 232 is energized, the substrate 3b is inclined toward the electrode plate 232 side.
In addition, by energizing both the electrode plates 231 and 232 of the electrode portion 23f, the substrate 3b can be displaced in the vertical direction as in the first embodiment.

Thus, by changing the energization pattern of the electrode portion 23f, the posture of the substrate 3b can be easily and reliably changed.
Further, the electrode part 23g shown in FIG. 8 has the same action and effect as the electrode part 23e, and the electrode part 23h has the same effect as the electrode part 23f.
In the optical device 1A having such a configuration, by changing (selecting) the energization pattern between the electrode part 23e and the electrode part 23f, the parallel state in which the substrate 3a and the substrate 3b are substantially parallel, and the substrate 3a and the substrate 3b are obtained. Can be in a non-parallel state where they are non-parallel.

Similarly, by changing (selecting) the energization pattern between the electrode portion 23g and the electrode portion 23h, the parallel state in which the substrate 3c and the substrate 3d are substantially parallel to each other and the non-parallel state in which the substrate 3c and the substrate 3d are not parallel to each other. Parallel state can be taken.
In the parallel state, as described in the first embodiment, the incident light L1 is repeatedly reflected between the reflective film 312a and the reflective film 312b, causing interference, and light having a wavelength corresponding to the interval h1. L2 is emitted toward the adjacent second structural body U2. The light L2 incident on the second structure U2 is repeatedly reflected between the reflection film 312c and the reflection film 312d of the second structure U2, causing interference, and the light L3 having a wavelength corresponding to the interval h2. Can be emitted (transmitted) to the outside. That is, wavelength separation is performed.
In the non-parallel state, there are the following three patterns (states).
In addition, since the structure is the same in the 1st structure U1 and the 2nd structure U2, below, the 1st structure U1 is demonstrated as a representative, and about the 2nd structure U2, The description is omitted.

(1) A state in which the substrate 3a is inclined with respect to the horizontal substrate 3b.
(2) A state in which the substrate 3b is inclined with respect to the horizontal substrate 3a. That is, the pattern is the reverse of pattern (1).
(3) The substrate 3a and the substrate 3b are inclined with respect to the vertical direction (vertical direction) in the drawing.

In such a non-parallel state, the reflection of the light L1 is prevented from being repeated, and the emission (transmission) of the light L3 is prevented. Therefore, the optical device 1A has a function as a switch.
In the non-parallel state, the degree of attenuation of the light L1 between the reflective film 312a and the reflective film 312b can be controlled by controlling the parallelism between the substrate 3a and the substrate 3b. Further, the degree of attenuation of the light L2 between the reflective film 312c and the reflective film 312d can be controlled by controlling the parallelism between the substrate 3c and the substrate 3d. The degree of attenuation of the finally transmitted light L3 can be strictly controlled. Therefore, the optical device 1A has a function as an attenuator.

In the optical device 1A having the above configuration, a parallel state and a non-parallel state can be taken. Thereby, in a parallel state, it will be in the state in which wavelength separation is performed with respect to the light which has various wavelengths, and in a non-parallel state, it will be in the state in which wavelength separation is stopped or suppressed. Therefore, it can switch to each state easily and reliably.
The optical device of the present invention has been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each part constituting the optical device is an arbitrary configuration having the same function. Can be substituted. Moreover, other arbitrary components may be added.

Moreover, the optical device of the present invention may be a combination of any two or more configurations (features) of the above embodiments.
In addition, each of the substrates 3a, 3b, 3c, and 3d is not limited to a circular shape in plan view, and one of the substrates may have a circular shape in plan view.
Further, the shape of each substrate in plan view is not limited to a substantially circular shape, and may be, for example, a square, a rectangle, a rhombus, an ellipse, or the like.

Further, the present invention is not limited to the formation of antireflection films on the top surfaces of the substrates 3a and 3c and the bottom portions of the recesses 21a and 21c. For example, either one of the top surface of the substrate 3a and the bottom portion of the recess 21a, or The upper surface of the substrate 3c and the bottom of the recess 21c may be provided.
Similarly, the present invention is not limited to the formation of antireflection films on the bottom surfaces of the substrates 3b and 3d and the bottom portions of the recesses 21b and 21d. For example, one of the bottom surface of the substrate 3b and the bottom portion of the recess 21b, Alternatively, it may be provided on either the lower surface of the substrate 3d or the bottom of the recess 21d.

Each reflective film and each antireflective film is preferably composed of a multilayer film, but is not limited thereto, and may be composed of a single layer film.
In addition, each antireflection film itself preferably has an insulating property, but is not limited thereto, and for example, an insulating film may be separately provided. In that case, a SiO ₂ layer formed by thermal oxidation may be provided, or a SiO ₂ layer formed by TEOS-CVD may be provided.

It is sectional drawing (side view) which shows 1st Embodiment of the optical device of this invention. FIG. 2 is a cross-sectional view (plan view) taken along line AA of the optical device shown in FIG. 1. It is a figure which shows each wavelength distribution of each light L1, L2, and L3. It is a figure explaining the manufacturing method of the optical device shown in FIG. 1 (the figure which shows a manufacturing process typically). It is a figure explaining the manufacturing method of the optical device shown in FIG. 1 (the figure which shows a manufacturing process typically). It is a figure explaining the manufacturing method of the optical device shown in FIG. 1 (the figure which shows a manufacturing process typically). It is a figure explaining the manufacturing method of the optical device shown in FIG. 1 (the figure which shows a manufacturing process typically). It is sectional drawing (side view) which shows 2nd Embodiment of the optical device of this invention. It is a BB sectional view (plan view) of the optical device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A ... Optical device 2a, 2b, 2c, 2d, 2d '... Housing 20a, 20b, 20c, 20d ... Housing main body 21a, 21b, 21c, 21d ... Recessed part 211 ... Bottom part 23a, 23b, 23c , 23d, 23e, 23f, 23g, 23h... Electrode portion 231, 232, 233... Electrode plate 25... Gap 3a, 3b, 3c, 3d. ... Reflective film 32 ... Supporting part 33 ... Silicon layer (silicon film) 331 ... Inner peripheral part 4 ... Intermediate layer 5 ... Transparent substrate 6 ... Mask layer 61 ... Opening 7 ... Wafer 71 ... Si base layer 72 ...... SiO ₂ layer 73 ...... upper Si layer 8 ...... through holes 10A, 10B, 10C, 10D ...... structure 11 ...... spacers 100a, 100d, 10a, 210b, 210c, 210d, 311a, 311b, 311c, 311d ... Antireflection film 400 ... Light source L1, L2, L3 ... Light h1, h2 ... Spacing, U1 ... First structure, U2 ... ... second structure, FSR1, FSR2 ... peak interval

Claims (11)

Of the incident light, an optical device that transmits light in a specific wavelength range,
A pair of first reflecting films and a first displacing means for moving the first reflecting films closer to and away from each other, and setting an interval between the first reflecting films by the first displacing means; Then, in this state, the light is incident, reflection is repeated between the pair of first reflection films, and interference is generated, so that light in a wavelength region corresponding to the interval between the first reflection films is obtained. A first structure configured to be able to pass through;
A pair of second reflecting films and a second displacing means for moving the second reflecting films closer to and away from each other, and setting an interval between the second reflecting films by the second displacing means; In this state, light that has passed through the first structure is incident, and reflection is repeated between the pair of second reflection films to cause interference. A second structure that is configured to transmit light in a wavelength range corresponding to the interval to the outside;
An optical device comprising the first structure and the second structure arranged along an optical axis of the incident light.   By setting the distance between the first reflective films to be different from the distance between the second reflective films, the wavelength range of light transmitted through the first structure and the second structure are determined. The optical device according to claim 1, wherein a wavelength range of transmitted light is different.   The optical device according to claim 2, wherein the first structural body and the second structural body share a wavelength range of light to be removed.   At least one of the pair of first reflective films and the pair of second reflective films is configured to prevent transmission of the light by setting a non-parallel state when setting the interval between them. The optical device according to claim 1.   5. The optical device according to claim 1, wherein at least one of the first displacement means and the second displacement means is operated by an action of a Coulomb force.   The first displacing means supports the pair of first reflective films, and has a pair of first substrates having light transmittance, and a pair of first substrates disposed to face the first substrates. The optical device according to claim 5, further comprising an electrode portion.   The second displacing means supports the pair of second reflective films, and has a pair of second substrates having optical transparency, and a pair of second substrates disposed to face the second substrates. The optical device according to claim 5, further comprising an electrode portion. The first structure includes a pair of housings having a pair of recesses capable of accommodating the first reflective film and the first displacement means;
The optical device according to claim 1, further comprising a spacer that joins the housings so that the recesses face each other. The second structure includes a pair of housings having a pair of recesses capable of accommodating the second reflective film and the second displacement means;
The optical device according to claim 1, further comprising a spacer that joins the housings so that the recesses face each other.   The optical device according to claim 1, wherein the first structure body and the second structure body are bonded via an intermediate layer. The refractive index of the intermediate layer is substantially equal to a refractive index of a portion of the first structure through which the light is transmitted and a refractive index of a portion of the second structure through which the light is transmitted. Optical device.

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