JPH09292520A - Diffraction grating type polarizer, optical parts using the same and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diffraction grating type polarizer which is easy to manufacture control and design and has high aging stability of performance, optical parts using the same, and methods for manufacturing them. SOLUTION: On the first optical material of this polarizer, a double refraction material 1 and a second optical material 2 are alternatively arranged and joined via an adhering layer 5 and the double refraction material 1 and the second optical material 2 have the same thickness dB. In this case, both main surfaces of the double refraction material 1 and the second optical material 2 have the same ground surfaces and refractive index of the second optical material 2 (nE2 ) and refractive indexes of the double refraction material 1 (nB1 , nB2 ) to two proper linearly polarized light beans nearly satisfy the relations: (nB2 -nE2 ) dB=(M+1/2)λ (M is an arbitary integer and λ is a wavelength of light) and nB1 =nE2 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffraction grating type polarizer excellent in mass productivity, which replaces a conventional polarizer or an optical component using the same, an optical component using the same, and a manufacturing method thereof.

[0002]

2. Description of the Related Art
The following various polarizers are known.

(1) Dichroic polarizer known as a so-called polaroid plate: This type of polarizer has a low extinction ratio and a large loss, so that it is difficult to use it for a precision optical component such as an optical isolator. there were.

(2) Polarizing prism using a birefringent crystal:
This type of polarizer uses a birefringent material such as quartz, calcite, magnesium fluoride, etc., and these must be cut out at a predetermined angle with respect to the crystal axis and processed into a prism shape, so the material cost is low. It was expensive and not easy to manufacture.

(3) Birefringent crystal plate: This type of polarizer has a function of selecting one polarization by shifting the beam of one polarization, and is a plate for use in a parallel beam system. It was necessary to increase the thickness and it was difficult to reduce the thickness.

(4) Polarizing glass: This type of polarizer has excellent characteristics and can be made thin, but it is difficult to manufacture and expensive.

On the other hand, as an alternative to the above-mentioned polarizer,
A birefringent diffraction grating type polarizer is known which is small in size and has high mass productivity.

(5) Birefringent Diffraction Grating-Type Polarizer: This type of polarizer separates optical paths by utilizing the difference in diffraction efficiency due to polarized light, and the following are known.

(5-1) According to JP-A-63-55501: A polarizer having a diffraction grating formed by subjecting lithium niobate to proton ion exchange. However, this polarizer has a problem that it cannot be manufactured at low cost because the single crystal substrate of lithium niobate that forms the diffraction grating is expensive, and it is difficult to control the polarization phase difference with high accuracy. There was a problem that it could not be manufactured stably with good performance.

(5-2) According to Japanese Patent Application Laid-Open No. 2-156205: A polarizer in which a dielectric layer is provided at the bottom of periodic grooves provided on the main surface of a crystal plate having optical anisotropy. However, although this polarizer can be manufactured at low cost,
Since it is difficult to precisely control the depth of the groove and the thickness of the dielectric layer, it is not possible to control the polarization phase difference with high accuracy, and as with (5-1), it is stable with good reproducibility. Could not be manufactured.

(5-3) According to Japanese Patent Laid-Open No. 6-308326: It is an improved invention of the polarizer of (5-2) by the present inventor. In this polarizer, as shown in FIG. 9, the birefringent material 1 having a uniform thickness joined to the upper surface of the optical material 10 with an adhesive 11 is grooved to penetrate the optical material 10, After that, since the groove is filled with the adhesive filler 12, the thickness of the birefringent material 1 can be made constant regardless of the depth of the groove. Therefore, the dependence of the polarizer performance on the groove depth accuracy is eliminated.

However, in the case of this polarizer, its performance depends on the refractive index of the adhesive filler filled in the groove, and therefore, in order to stably manufacture a polarizer having a certain performance, the adhesive filler is used. The mixing ratio of the agents (mixing ratio of the mixture which is a component of the adhesive filler), the curing conditions, and the like need to be constantly controlled, which is not easy to control. In addition, this polarizer has the following problems.

(1) In order to obtain a polarizer having desired performance, it is necessary to adjust the refractive index of the adhesive filler with high precision, and the precision of the adjustment is not good. For example, in the method of adjusting the refractive index of the epoxy resin cured product disclosed in JP-B-63-28448, the accuracy with which the refractive index can be adjusted is about 0.001.

(2) Since it is difficult to accurately predict the refractive index after curing before curing, the design efficiency of the polarizer was not good (a considerable number of trials were required).

(3) Since the adhesive filler is a resin material, the environment resistance is poor and the refractive index of the adhesive filler changes over time, and the performance of the polarizer deteriorates (the extinction ratio decreases). was there.

(4) If the accuracy of the refractive index of the adhesive filler is poor, the roughness of the bottom surface of the groove portion may cause scattering and the characteristics may be deteriorated.

Therefore, the present invention solves the above-mentioned problems of the polarizer of (5-3), facilitates manufacturing control and design, and has high stability of performance with time. It is an object of the present invention to provide a conventional optical component and a manufacturing method thereof.

[0018]

A diffraction grating type polarizer according to claim 1, wherein a birefringent material and a second optical material are alternately arranged and bonded on a first optical material via an adhesive layer. In the diffraction grating type polarizer in which the birefringent material and the second optical material have the same thickness d _B , both main surfaces of the birefringent material and the second optical material have the same polishing surface. And second
The refractive index n _E2 of the optical material and the refractive indices n _B1 and n _{B2 of} the birefringent material with respect to two unique linearly polarized light are (n _B2 −n _E2 ) d _B = (M + 1/2) λ (where M Is an arbitrary integer, λ is the wavelength of light), and n _B1 = n _E2 is substantially satisfied.

A diffraction grating type polarizer according to a second aspect is the diffraction grating type polarizer according to the first aspect, wherein the second optical material is optical glass and the birefringent material is quartz. It is characterized by being.

A method of manufacturing a diffraction grating type polarizer according to a third aspect of the present invention is such that the refractive indexes n _B1 and n _B2 for two unique linearly polarized lights.
Forming a plurality of first grooves having a constant spacing in the birefringent material having a refractive index n _E2 , and forming a plurality of second grooves having a constant spacing in the second optical material having a refractive index n _E2 And fitting the respective concave and convex portions of the member having the first groove and the member having the second groove with an adhesive interposed therebetween,
Bonding to form a composite, polishing one surface of the composite to a thickness at which both surfaces of the birefringent material and the second optical material appear to form a first polished surface; Bonding the first optical material to the first polishing surface of the body with an adhesive interposed between the first polishing surface and the second polishing surface of the composite. And a step of polishing the surface to a predetermined thickness.

A method of manufacturing a diffraction grating type polarizer according to a fourth aspect is the method of manufacturing a diffraction grating type polarizer according to the third aspect, wherein the second optical material is optical glass, and
The birefringent material is quartz.

In the optical component according to a fifth aspect, the birefringent material and the second optical material are alternately arranged and bonded via an adhesive layer on at least one surface of the magneto-optical element or the electro-optical element. In the optical component in which the birefringent material and the second optical material have the same thickness d _B , both main surfaces of the birefringent material and the second optical material have the same polishing surface, and
The refractive index n _E2 of the second optical material and the refractive indices n _B1 and n _{B2 of} the birefringent material with respect to two unique linearly polarized lights are (n _B2 −n _E2 ) d _B = (M + 1/2) λ ( Here, M is an arbitrary integer, λ is the wavelength of light), and n _B1 = n _E2 is substantially satisfied.

An optical component according to a sixth aspect is the optical component according to the fifth aspect, wherein the second optical material is optical glass and the birefringent material is quartz. It is a thing.

The method of manufacturing an optical component according to claim 7 is 2
Forming a plurality of first grooves having a constant spacing in a birefringent material having refractive indices n _B1 and n _B2 for two unique linearly polarized lights; and having a constant spacing in a second optical material having a refractive index n _E2. Forming a plurality of second grooves having a groove, and fitting and joining the concave and convex portions of the member having the first groove and the member having the second groove with an adhesive agent interposed therebetween. Forming a composite body, polishing one surface of the composite body to a thickness at which both surfaces of the birefringent material and the second optical material appear to form a first polished surface, and the composite body First of
A step of bonding a magneto-optical element or an electro-optical element to the polishing surface of the composite with an adhesive interposed, and a surface opposite to the first polishing surface of the composite is coated with both surfaces of the birefringent material and the second optical material. And a step of polishing to a predetermined thickness that appears.

An optical component manufacturing method according to claim 8 is the optical component manufacturing method according to claim 7, wherein the second optical material is optical glass and the birefringent material is quartz. It is characterized by being.

[0026]

The diffraction grating type polarizer according to claim 1 will be described together with the operation principle of the diffraction grating type polarizer.

As shown in FIG. 1, a first area 8 and a second area 9
If the phase difference between the light passing through the first region 8 and the light passing through the second region 9 is φ, the intensity of the 0th-order diffracted light, that is, the transmittance T of the light traveling straight ahead is Is sufficiently thin, it is given by the following approximate expression.

T = cos ² (φ / 2) (1) Here, the phase difference between one of the two linearly polarized light beams orthogonal to each other is φ1, the transmittance is T1, and the phase difference between the other linearly polarized light is Is φ2 and the transmittance is T2, it operates as a polarizer when T1 is approximately 1 (φ1 is approximately 0 deg) and T2 is approximately 0 (φ2 is approximately 180 deg). That is, when the extinction ratio T2 / T1 is small, it operates as a polarizer.

Since the control of T1 is relatively easy,
In order to obtain a polarizer having a small extinction ratio value, the accuracy of controlling T2 becomes a problem. Here, the control of T1 means φ so that the value of T (T1) in Expression (1) approaches 1.
It is to control the value of (φ1), and the control of T2 is
Φ so that the value of T (T2) in equation (1) approaches 0
It is to control the value of (φ2).

For example, when T1 is almost 1, in order to keep the extinction ratio below 0.0005, φ2 is 180 ± 2.
It is necessary to control so as to be within the range of 6 deg.

By the way, in the diffraction grating type polarizer according to the present invention, the above-mentioned phase difference φ is caused by the difference between the refractive indices n _B1 and n _B2 of the birefringent material and the refractive index n _E2 of the second optical material. .Phi.1 and .phi.2 are given by the following equations.

Φ1 = {360 deg × (n _B1 −n _E2 ) d} / λ (2) φ2 = {360 deg × (n _B2 −n _E2 ) d} / λ ... (3) where For φ1, if n _B1 = n _E2 is substantially satisfied, then φ1 in equation (2) becomes approximately 0 deg. Further, for φ2, (n _B2 −n _E2 ) d _B = (M + 1/2) λ ·· If (4) (where M is an arbitrary integer and λ is the wavelength of light) is substantially satisfied, φ2 in equation (3) becomes an odd multiple of approximately 180 deg, and the diffraction grating polarizer operates.

In the diffraction grating type polarizer according to the present invention, since the refractive index n _B1 of the birefringent material and the refractive index n _E2 of the second optical material are substantially the same, φ1 is particularly controlled. Does not need Further, since the refractive index n _B2 of the birefringent material and the refractive index n _E2 of the second optical material are determined by the materials thereof, in order to control φ2 with high accuracy, it is sufficient to increase the accuracy of the thickness d. In the present invention, by making the both surfaces of the portion in which the birefringent material and the second optical material are alternately arranged as the polishing surface, the accuracy of the thickness d of the portion sandwiched between both polishing surfaces can be improved. I am trying to

Further, in the diffraction grating type polarizer according to the present invention, the refractive index n _E2 of the second optical material and the refractive index n _B2 of one of the birefringent materials should be precisely measured before production. Therefore, the design of the polarizer (setting of the thickness d, etc.) is facilitated, and the product yield is improved.

If optical glass is used as the second optical material, the refractive index can be controlled more precisely (accuracy of ± 0.0002 at a practical level). Further, since the refractive index of optical glass is easily matched with that of quartz, φ1 is 0
It becomes easier to control the refractive index of the optical glass so that it becomes deg.

Further, since the optical glass and the crystal are excellent in environmental resistance, the refractive index does not change with time and the performance of the polarizer is hardly deteriorated (the extinction ratio is decreased).

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION [Structure of Diffraction Grating Polarizer] The structure of the diffraction grating polarizer according to the present invention will be described according to the manufacturing process thereof.

Step 1: Prepare a birefringent material 1 having refractive indexes n _B1 and n _B2 for two unique linearly polarized lights, and as shown in FIG. 2, space the birefringent material 1 with a dicing saw or a peripheral cutting machine. A plurality of first grooves 6 having a width w2 and having a width w1 are formed. Here, it is preferable that w1 be slightly narrower than w2. Also, the depth of the first groove 6 is determined by the final birefringent material 1.
The thickness is determined to be deeper than the thickness d.

Step 2: Prepare a second optical material 2 having a refractive index n _E2 which is almost the same as n _B1 and, as shown in FIG. 3, use a dicing saw or an outer peripheral cutting machine to space the second optical material 2. A plurality of second grooves 7 having a width w4 are formed with a width w3. here,
w3 and w4 are almost equal to w1, w3 is w4
It is preferable to make it slightly narrower. Also, the second groove 7
Is set to be deeper than the final thickness d of the second optical material 2.

Step 3: As shown in FIG. 4, the birefringent material 1 (FIG. 2) produced in step 1 and the second birefringent material produced in step 2
The concavo-convex portions provided on the portion made of the optical material 2 (FIG. 3) are fitted and joined with the adhesive layer 4 interposed therebetween to produce the composite body 8. Here, as the adhesive, it is possible to use a transparent organic adhesive, a low melting point glass, or the like at the wavelength used.

Step 4: As shown in FIG. 5, one surface of the composite 8 is polished and polished to a thickness at which a surface in which the birefringent material 1 and the second optical material 2 are alternately arranged appears to form a polished surface 9. To do.
In FIG. 5, polishing is performed from the birefringent material 1 side, but polishing may be performed from the second optical material side 2.

Step 5: As shown in FIG. 6, the polishing surface 9 of the composite body produced in Step 4 and the first optical material 3 are bonded with the adhesive layer 5 interposed. Here, as the adhesive, it is possible to use a transparent organic adhesive, a low melting point glass, or the like at the wavelength used. Since the adhesive layer 5 is uniformly provided in both the first region 13 and the second region 14 (FIG. 1), the performance of the polarizer is improved even if the refractive index of the adhesive filler changes. Does not decrease (the extinction ratio decreases).

Step 6: As shown in FIG. 7, the surface opposite to the surface polished in Step 4 is (n _B2 -n _E2 ) d _B = (M + 1/2) λ (4) (where M is Polish to a thickness d that substantially satisfies an arbitrary integer, λ is the wavelength of light. Here, the thickness d _B of the portion where the birefringent material 1 and the second optical material 2 are alternately arranged is smaller than that of the first groove 6 (FIG. 2) and the second groove 7 (FIG. 3). Since it is set as follows, when polishing to thickness d,
Both surfaces of the birefringent material 1 and the second optical material 2 appear.

In the manufacturing method according to the present invention, even if there is roughness on the bottom surface of the grooved recess, since this portion is finally removed by polishing, the scattering loss due to the surface roughness will not occur. It doesn't matter. However, it is desirable to process the side surface of the recess, that is, the boundary surface between the birefringent material and the second optical material, to a surface that is as rough as possible.

Although not shown in FIGS. 4 to 7,
An adhesive may be present on the boundary surface, and in this case, it is preferable that the refractive index of the adhesive be close to the refractive index of the second optical material.

Although it is theoretically possible to omit the step 5 of joining the first optical material and use only the birefringent material and the second optical material as the polarizer, the thickness d _B is usually used. Is so thin that it breaks and is not practical.

[Operation of Diffraction Grating Polarizer] The polarizer thus obtained operates as follows for two unique linearly polarized lights.

(1) Linearly polarized light with respect to n _{B1 Since} the refractive index n _B1 of one of the birefringent materials 1 and the refractive index n _E2 of the second optical material 2 are almost the same, the first region 13 and the second region 14 are The phase difference φ1 of the light passing through is 0 deg, and the light does not diffract and travels straight without loss.

(2) Linearly polarized light with respect to n _B2 The thickness d _B of the portion in which the birefringent material 1 and the second optical material 2 shown in FIG. For n _B2 and the refractive index n _{E2 of} the second optical material 4,
Since it is manufactured so as to substantially satisfy the expression (4), the phase difference φ2 of the light passing through the first region and the second region becomes approximately 180 deg, and the light is diffracted.

[Optical Material Constituting Diffraction Grating Polarizer] As the birefringent material constituting the diffraction grating polarizer, any transparent birefringent material can be used. Typical materials include quartz, calcite, sapphire, ADP, KDP, rutile, and the like. Particularly, quartz that is inexpensive and easy to process is suitable as the birefringent material of the present invention.

Although any transparent isotropic material can be used as the second optical material, it is preferable to use optical glass capable of controlling the refractive index with high accuracy.

It should be noted that quartz is used as the birefringent material, and the second
If optical glass is used as the optical material of (3), the refractive index n _E2 of the optical glass can be easily matched with the refractive index n _B1 of one of the crystals, so that it is easier to set the phase difference φ to 0 deg.

Any optical material can be used as the first optical material.

For example, if a magneto-optical element (Faraday rotator) is used as the first optical material, an optical isolator,
Magneto-optical components such as optical circulators, optical switches, and optical magnetic field sensors can be manufactured.

If an electro-optical element is used as the first optical material, electro-optical parts such as an optical modulator, an optical switch and an optical electric field sensor can be manufactured.

[0056]

【Example】

[Example 1] An x-cut quartz plate was used as a birefringent material.
The case where the optical glass of the material FEL1 is used as the optical material will be described by showing specific numerical values. Where wavelength 1
At 550 nm, the refractive index of ordinary light of quartz is n _B1 = 1.5
2781, the refractive index of extraordinary light is n _B2 = 1.53630, F
The refractive index of EL1 was n _E2 = 1.52854. The thickness of the crystal and the second optical material before processing was 600 μm. Further, as the first optical material, the optical glass of the material FEL1 was used.

Steps 1, 2: w1, w2, w3, w4 were set to about 100 μm and the depth of the groove was set to about 300 μm, and grooves were formed in the quartz plate (birefringent material) and the second optical material (optical glass). .

Step 3: A quartz plate (birefringent material) and a second optical material (optical glass) were bonded together using an optical adhesive to form a composite.

Step 4: From the side of the quartz plate,
Crystal plate (birefringent material) and second optical material (optical glass)
About 400 μm was polished so that both surfaces were exposed.

Step 5: The first optical material (optical glass) was bonded to the polished surface of this composite using an optical adhesive.

Step 6: Finally, the composite in which the first optical material (optical glass) is bonded is polished from the second optical material side, and the quartz plate (birefringent material) and the second optical material (optical) are polished. The thickness of the glass) was set to 100 μm.

When the optical characteristics of the diffraction grating type polarizer produced in this way were evaluated, excellent characteristics with an extinction ratio of 0.0001 were obtained.

Since the refractive index of the optical glass varies somewhat depending on the lot, it is desirable to measure the refractive index for each lot and determine the thickness d according to the measured refractive index of the optical glass. Further, in the first embodiment, the formula (4)
The value of M in M was set to M = 0, but normally n _B2 > n _E2
In this case, it is preferable to set M = 0, and in the case of n _B2 <n _E2 , set M = −1. By setting in this way, the wavelength band that operates as a polarizer becomes the widest.

[Embodiment 2] An x-cut quartz plate as a birefringent material, an optical glass of material FEL1 as a second optical material, and a Faraday having a rotation angle of 45 ° at a wavelength of 1.3 μm used as a first optical material. -With a rotor.
The manufacturing method was the same as in Example 1.

A polarizing glass is arranged on the opposite side of the diffraction grating type polarizer using a Faraday rotator as the first optical material as shown in FIG. 8 to form an optical isolator. Here, the polarizing glass has a transmission polarization plane of 45 ° with respect to the polarization plane of light that passes through a quartz plate (birefringent material) as ordinary light.
It is arranged in a rotated state (rotated in the rotation direction of the Faraday rotator).

When the characteristics of this optical isolator were measured, the insertion loss was 0.15 dB and the isolation was 43 d.
A good characteristic of B was obtained.

Even if the diffraction grating type polarizer of the present invention is arranged on both sides of the Faraday rotator without using the polarizing glass, it operates as an optical isolator. In this case, the optical isolation
Can be very thin.

[0068]

Since the present invention is configured as described above, it has the following effects.

(1) Since the thickness d _B of the birefringent material and the second optical material can be accurately manufactured, an ideal diffraction grating type polarizer having good characteristics can be manufactured with good reproducibility and stability. be able to.

If a magneto-optical element or an electro-optical element is used as the first optical material, a thin magneto-optical element or electro-optical element can be stably manufactured with good reproducibility.

(2) Since the refractive indexes of the optical material and the birefringent material, which are the main constituent members, can be precisely measured before fabrication, it is easy to design the diffraction grating type polarizer and control the phase difference. .

(3) Since the optical material and the birefringent material having excellent environment resistance are used as the main constituent members, the performance of the diffraction grating type polarizer hardly deteriorates due to changes with time.

(4) If optical glass is used as the optical material and quartz is used as the birefringent material, it becomes easier to design the diffraction grating type polarizer and control the phase difference. Also, the environmental resistance is further improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the operating principle of a diffraction grating type polarizer.

FIG. 2 is a cross-sectional view showing step 1 of a production example of a polarizer of the present invention.

FIG. 3 is a cross-sectional view showing step 2 of the production example of the polarizer of the present invention.

FIG. 4 is a cross-sectional view showing step 3 of a production example of a polarizer of the present invention.

FIG. 5 is a cross-sectional view showing step 4 of the production example of the polarizer of the present invention.

FIG. 6 is a cross-sectional view showing step 5 of a production example of a polarizer of the present invention.

FIG. 7 is a cross-sectional view showing step 6 of a production example of a polarizer of the present invention.

FIG. 8 is a configuration diagram of an optical isolator according to a second embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a conventional polarizer.

[Description of Reference Signs] 1 birefringent material 2 second optical material 3 first optical material 4 adhesive layer 5 adhesive layer 6 first groove 7 second groove 8 complex 9 polishing surface 13 first region 14th Region 2 15 Faraday rotator 16 Polarizing glass

Claims (8)

[Claims] 1. A birefringent material and a second optical material on the first optical material.
The optical materials of and are alternately arranged and bonded through the adhesive layer,
In a diffraction grating type polarizer in which the birefringent material and the second optical material have the same thickness d _B , both main surfaces of the birefringent material and the second optical material have the same polishing surface. Further, the refractive index n _E2 of the second optical material and the refractive indexes n _B1 and n _{B2 of} the birefringent material for two unique linearly polarized lights are (n _B2 −n _E2 ) d _B = (M + 1/2) ) Λ (where M is an arbitrary integer, λ is the wavelength of light) and n _B1 = n _E2 is substantially satisfied. 2. The diffraction grating type polarizer according to claim 1, wherein the second optical material is optical glass, and the birefringent material is quartz. Diffraction grating type polarizer. 3. Refractive index n for two unique linearly polarized lights
Forming a plurality of first grooves at regular intervals in a birefringent material having _B1 and n _B2, and a second having a refractive index n _E2
And a step of forming a plurality of second grooves having a constant interval in the optical material, and an adhesive agent intervenes between the uneven portions of the member having the first groove and the member having the second groove. And fitting and joining to form a composite body, and one surface of the composite body is polished to a thickness at which both surfaces of the birefringent material and the second optical material appear to form a first polished surface. Process,
A step of bonding a first optical material to the first polishing surface of the composite body with an adhesive interposed; and a step of forming a surface opposite to the first polishing surface of the composite body with a birefringent material and a second optical material. A method of manufacturing a diffraction grating type polarizer, comprising a step of polishing to a predetermined thickness where both surfaces appear. 4. The method for manufacturing a diffraction grating type polarizer according to claim 3, wherein the second optical material is optical glass, and the birefringent material is quartz. Item 4. A method of manufacturing a diffraction grating type polarizer according to item 3. 5. The birefringent material and the second optical material are alternately arranged and bonded on at least one surface of the magneto-optical element or the electro-optical element via an adhesive layer, and the birefringent material and the second optical material are bonded together. In the optical component having the same thickness d _B , the both major surfaces of the birefringent material and the second optical material have the same polishing surface, and the optical material of the second optical material The index of refraction n _E2 and the indices of refraction n _B1 and n _B2 for the two unique linearly polarized lights of the birefringent material are (n _B2 −n _E2 ) d _B = (M + 1/2) λ (where M is any integer) , Λ is the wavelength of light) and n _B1 = n _E2 . 6. The optical component according to claim 5, wherein the second optical material is optical glass, and the birefringent material is quartz. . 7. A refractive index n for two unique linearly polarized lights.
Forming a plurality of first grooves at regular intervals in a birefringent material having _B1 and n _B2, and a second having a refractive index n _E2
And a step of forming a plurality of second grooves having a constant interval in the optical material, and an adhesive agent intervenes between the uneven portions of the member having the first groove and the member having the second groove. And fitting and joining to form a composite body, and one surface of the composite body is polished to a thickness at which both surfaces of the birefringent material and the second optical material appear to form a first polished surface. Process,
A step of bonding a magneto-optical element or an electro-optical element to the first polishing surface of the composite body with an adhesive interposed; and a surface opposite to the first polishing surface of the composite body with a birefringent material and second optical And a step of polishing to a predetermined thickness where both surfaces of the material are exposed. 8. The method of manufacturing an optical component according to claim 7, wherein the second optical material is optical glass, and
8. The birefringent material is quartz crystal.
A method for manufacturing the described optical component.