JP2003186375A - Method for manufacturing optical component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical component with an optical axis adjustment mechanism. <P>SOLUTION: A PBS 3 and an optical adjustment mechanism 8 mounted on the PBS 3 are installed on a reference surface 23 below a laser light PO emitted from a laser collimator 20. A bottom surface of the PBS 3 is coated with an ultraviolet curing resin 22. A surface of a second moving holder 2 adheres to the bottom surface of the PBS 3. If the laser collimator 20 has a predetermined angle or more, the ultraviolet curing resin 22 has viscosity when the ultraviolet curing resin 22 is intermittently irradiated with ultraviolet rays. As a return angle of the laser collimator 20 is observed in this state, a gradient of the PBS 3 is corrected so as to keep the predetermined angle of the laser collimator 20 or less. Then, the ultraviolet curing resin 22 are continuously irradiated with the ultraviolet rays and cured. The surface of the second moving holder 2 adheres to the bottom surface of the PBS 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical component, and more particularly to a method for manufacturing an optical component mounted on an optical axis adjusting mechanism used for hologram recording.

[0002]

2. Description of the Related Art Holographic recording, which records information on a recording medium by utilizing holography, generally causes an information beam having image information and a reference beam to overlap each other inside the recording medium and causes interference at that time. This is done by writing stripes on the recording medium. At the time of reproducing the recorded information, by irradiating the recording medium with the reference light, the image information is reproduced by the diffraction due to the interference fringes.

In recent years, volume holography, particularly digital volume holography, has been developed in the practical range and has attracted attention for ultra-high density optical recording. Volume holography is a method in which interference fringes are three-dimensionally written by positively utilizing the thickness direction of a recording medium. Increasing the thickness enhances diffraction efficiency, and multiple recording increases the recording capacity. The feature is that it can be achieved. And
The digital volume holography is a computer-oriented holographic recording method in which the image information to be recorded is limited to a binarized digital pattern while using the same recording medium and recording method as the volume holography. In this digital volume holography, image information such as an analog picture is once digitized, developed into two-dimensional digital pattern information, and recorded as image information. At the time of reproduction, the digital pattern information is read and decoded to restore the original image information for display. As a result, even if the SN ratio (signal-to-noise ratio) is slightly worse during reproduction, differential detection is performed or 2
By encoding the value-coded data and performing error correction, the original information can be reproduced extremely faithfully.

A recording / reproducing system in such a conventional digital volume holography is a hologram recording by recording a spatial light modulator for generating information light based on two-dimensional digital pattern information, and collecting the information light from the spatial light modulator. A lens for irradiating the medium, a reference light irradiating means for irradiating the hologram recording medium with the reference light in a direction substantially orthogonal to the information light, and a CCD (charge for detecting reproduced two-dimensional digital pattern information). (Combination element) array and reproducing light emitted from the hologram recording medium are condensed to form a CCD
And a lens for illuminating the array. A hologram recording material such as a crystal such as LiNbO ₃ or a photopolymer is used for the hologram recording medium.

With the above-mentioned structure, information can be recorded in multiple layers on the same hologram recording medium, but positioning of the information beam and the reference beam with respect to the hologram recording medium is important in order to record information at an extremely high density. . However, in the above configuration, since the hologram recording medium itself has no information for positioning, the information light and the reference light are mechanically positioned with respect to the hologram recording medium, and it is difficult to perform highly accurate positioning. Therefore, the removability (the ease of moving the hologram recording medium from one recording / reproducing device to another recording / reproducing device to perform the same recording / reproducing) is poor, and random access is difficult and high-density recording is difficult. There is a problem that is. Further, since the optical axes of the information light, the reference light and the reproduction light are spatially arranged at mutually different positions, the size of the optical system for recording or reproduction increases, and the information light, the reference light and the reproduction light There is a problem in that it is difficult to align each optical axis of.

As means for solving the above-mentioned problems, there is, for example, "Optical information recording apparatus and method and optical information reproducing apparatus and method" disclosed in Japanese Patent Laid-Open No. 11-311937. The pickup in such a form includes a light source device that emits coherent linearly polarized laser light,
A collimator lens, a neutral density filter (hereinafter referred to as an ND filter), an optical element for optical rotation, and a polarization beam splitter (which are sequentially arranged from the light source device side in the traveling direction of the light emitted from the light source device). It is provided with a PBS (hereinafter abbreviated as PBS), a phase spatial light modulator, a beam splitter (hereinafter abbreviated as BS), and a photodetector. The light source device emits linearly polarized light of S polarization or P polarization. The S-polarized light is a linearly polarized light whose polarization direction is perpendicular to the incident surface, and the P-polarized light is a linearly polarized light whose polarization direction is parallel to the incident surface, and will be used in the same meaning below.

The PBS reflects the S-polarized component and transmits the P-polarized component of the light emitted from the optical element for optical rotation.
It has a BS surface.

The BS has a beam splitter surface. The beam splitter surface transmits, for example, 20% of the P-polarized component and reflects 80% thereof.

[0009]

In the above invention, the information light and the reference light can be separated or coaxial with each other by the PBS, whereby the optical axes of the information light, the reference light and the reproduction light are spatially separated. Since they are arranged at positions different from each other, they contribute to miniaturization of the recording or reproducing optical system.

However, in this method, two PBSs and a B
Since S is used, it is necessary to accurately adjust the optical axis in order to match the basic optical axes, and even a slight angular error in the adjustment causes a large deviation of the optical axis. For example, in a large-scale recording / reproducing system for digital volume holography, the distance r between a plurality of optical systems may reach 100 mm. In this case, the inclination θ of the optical component is, for example, 5 mr.
Even with ad, the deviation d of the optical axis reaches 0.5 mm when calculated using a well-known formula of d = rθ.

Conventionally, in order to adjust the optical axis, an operator has used a thin jig such as a toothpick to gradually move the PBS back and forth and left and right to align the optical axes and fix it with an adhesive or the like. Since the PBS was small, it was difficult to fix it after adjustment and align it with a predetermined optical axis.

In particular, when a plurality of PBSs are used, one of them may be adjusted and fixed with an adhesive or the like, and then the other may be adjusted.
In some cases, due to the influence of one adjustment, the other optical axis cannot be aligned with the other adjustment. In such a case, it is necessary to remove one PBS previously adjusted and fixed with an adhesive or the like and readjust it. However, since it is fixed with an adhesive or the like, it is necessary to remove the PBS and clean the adhesive surface, and the workability is extremely poor.

On the other hand, if the optical axes are deviated when the two PBSs and BSs are fixed, each of the information light, the reference light and the reproduction light accurately interferes with each other in the recording layer of the hologram recording medium, and the hologram pattern is formed. There is a problem that it becomes a fatal defect when recording or reproducing.

In order to solve the above-mentioned problems, a method of aligning the basic optical axes from the outside of the device by using an optical axis adjusting device may be considered. However, such a device has a complicated structure and systematic alignment is required. Are difficult to achieve and increase the manufacturing cost.

The present invention has been made for the purpose of providing a method for manufacturing an optical component with an optical axis adjusting mechanism, which solves the above problem and can match the basic optical axes without using a special external device. Is.

[0016]

In order to achieve the above object, the present invention provides a method of manufacturing an optical component according to claim 1,
A method of manufacturing an optical component by a manufacturing apparatus having a reference surface having a predetermined accuracy, a laser collimator, and an ultraviolet irradiation device, wherein a laser collimator is arranged on the reference surface, and the reference is emitted from the laser collimator. The laser collimator is adjusted so that the angle of the laser beam returning from the surface to the laser collimator becomes zero, and the laser beam emitted from the laser collimator is below the laser beam emitted from the laser collimator. An optical adjustment mechanism and an optical component mounted thereon are installed on the reference surface so as to hit the component, and an ultraviolet curable resin is applied to the bottom surface of the optical component, and the optical component is reflected from the optical component. When the return light of the laser light emitted from the laser collimator is at a predetermined angle or more, The ultraviolet light is intermittently irradiated by the irradiation device for a short time to cure the ultraviolet curable resin to a viscous state, and the return light of the laser light emitted from the laser collimator reflected from the upper surface of the optical component is predetermined. If the return light of the laser light emitted from the laser collimator reflected from the upper surface of the optical component is within a predetermined angle, the ultraviolet curable resin is adjusted so that the inclination of the optical component is within the angle. To continuously (irradiate) the ultraviolet curing resin to sufficiently (completely) cure the ultraviolet curable resin and fix the optical component to the optical adjusting mechanism to manufacture an optical component with an optical adjusting mechanism. Is characterized by.

In the method of manufacturing an optical component according to claim 2,
Of the laser light emitted from the laser collimator, the surface of the optical adjustment mechanism on which the optical component is mounted or the bottom surface of the optical component is made black, and the reflected light from the bottom of the optical component is removed. The tilt of the optical component is adjusted by using the reflected light from the upper surface of the above as the angle of the return light of the laser light emitted from the laser collimator, and the optical component with an optical adjustment mechanism is manufactured.

In the method of manufacturing an optical component according to claim 3,
The ultraviolet ray emitted from the ultraviolet ray irradiating device is emitted obliquely from above so as to pass through the optical component and reach the bottom surface thereof.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described. In the following description, an embodiment will be described as a polarization beam splitter with an optical axis adjusting mechanism that uses a polarization beam splitter (hereinafter referred to as PBS) as an optical component. However, the optical component may be a reflecting mirror, a beam splitter, a dichroic other than this. It may be an optical component such as a mirror that changes the direction and the optical path of light.

FIG. 1 is a perspective view of a PBS with an optical axis adjusting mechanism. The PBS mounted on the optical axis adjusting mechanism 8 will be described below with reference to FIG.
The fixing method of No. 3 will be described in detail. In FIG.
The optical axis adjusting mechanism 8 is composed of a first moving holder 1 and a second moving holder 2. In the optical axis adjusting mechanism 8, a first moving holder 1 is fixed to a base (not shown) with screws, and a second moving holder 2 is provided on the first moving holder 1.
Is fixed to the second moving holder 2, and
S3 is used by a predetermined method which will be described later, that is, it is adhered and fixed with an ultraviolet curing resin.

Further, in FIG. 1, the optical axis adjusting mechanism 8 is provided.
The adjustment jig 4 used when performing the optical axis adjustment of FIG. The adjustment jig 4 is removed from the base when the adjustment of the optical axis of the PBS 3 is completed.

The adjusting jig 4 has an adjusting through hole 4a, and the height (height from the base) H2 of the flat plate portion on which the adjusting through hole 4a is formed is the first side. When the second movable holder 2 is rotatably provided on the movable holder 1, up to a flat portion facing the lower surface of the flat plate portion in which the adjustment through hole 4a of the adjustment jig 4 of the second movable holder 2 is formed. Slightly higher than height H1.

The adjustment jig 4 has an adjustment through hole 4a penetrating therethrough, and is above the first movement adjustment groove 1b and the second movement adjustment groove 2b formed in the first movement holder 1 and the second movement holder 2. The adjustment through holes 4a are arranged so as to overlap with each other, and adjustment is performed.

The light L emitted from the light source device including a laser light source (not shown) that emits the light containing the S-polarized component and the P-polarized component by the PBS 3 is reflected by the S-polarized component and is converted into P as the light L1. The polarized component is transmitted and emitted as light L2 in different directions.

By moving the first moving holder 1 in the Y direction, the position of the PBS 3 on the incident optical axis is changed to the first position.
By rotating the second moving holder 2 around a rotation support shaft (not shown) provided in the moving holder 1, the PBS 3
The angle on the XY plane of the reflecting surface 3a is adjusted. That is, the optical axes of the reflected light L1 and the transmitted light L2 of the emitted light L are adjusted by the first moving holder 1 and the second moving holder 2.

As described above, the optical axis is adjusted by the first moving holder 1 and the second moving holder 2, but
Even if the movable holder 1 and the second movable holder 2 maintain a predetermined level of horizontality due to processing accuracy, if the PBS 3 is mounted on the second movable holder 2 while being inclined, the PBS 3
It is not possible to adjust the deviation of the optical axis due to tilting. Therefore, it is necessary to mount the PBS 3 on the second moving holder 2 without tilting before the optical axis is adjusted by the first moving holder 1 and the second moving holder 2.

FIG. 2 is an explanatory view of a method of fixing the PBS 3 mounted on the second moving holder 2 without tilting. The method of manufacturing the optical component according to the embodiment of the present invention will be described below with reference to FIG. In FIG. 2, the manufacturing apparatus includes a reference surface 23 having a predetermined accuracy, a laser collimator 20, and an ultraviolet irradiation device 21.

The reference surface 23 is a reference surface with a predetermined alignment, and may be, for example, an optical plate. The laser collimator 20 may be a known autocollimator, for example, emits a laser beam with a wavelength of about 630 nm,
The inclination of the measurement target is measured by the return angle of the reflected light from the measurement target.

The ultraviolet irradiation device 21 is an optical fiber 21.
d and 21c, and ultraviolet ray irradiators 21a and 21b respectively provided with heat ray cut filters or irradiation distribution improving lenses at the tips thereof, for example, HOYA-S
CHOTT EX250 (trade name), or HOYA-
Wavelength 2 such as SCHOTT EX250-W (trade name)
It is an ultraviolet irradiation device that irradiates ultraviolet rays of 50 nm to 450 nm to the outside. The heat ray cut filter or the irradiation distribution improving lens may be used as necessary, and the number of optical fibers may be one or more. P
The ultraviolet irradiator 21 is provided obliquely above the BS 3 and around the PBS 3 at a position where it does not interfere with the laser collimator 20.
A and 21b are provided so that the ultraviolet rays emitted from the ultraviolet ray irradiation portion pass through the PBS 3 and reach the ultraviolet curable resin 22 applied to the bottom surface 6 of the PBS 3.

Next, the laser collimator 20 is arranged on the reference surface 23, and the laser beam PR emitted from the laser collimator 20 and returning from the reference surface 23 to the laser collimator 20 is zeroed. The laser collimator 20 is adjusted and used as a horizontal reference.

Below the laser beam PO emitted from the laser collimator 20, the laser collimator 2
The optical adjustment mechanism 8 and the PBS 3 mounted on the optical adjustment mechanism 8 are installed on the reference surface 23 so that the laser light PO emitted from the laser light 0 strikes the PBS 3.

On the bottom surface 6 of the PBS 3, for example, World Lock No. manufactured by Kyoritsu Chemical Co., Ltd. 8120T3 (product name), or World Lock No. An ultraviolet curable resin 22 such as 8125 (product name) is applied to a thickness of 5 to 10 μm, and the surface of the second moving holder 2 and the PBS 3 are coated.
And the bottom surface 6 of the. The ultraviolet curable resin 22 is
The main component is modified acrylate, and the way of curing changes depending on the irradiation conditions of ultraviolet rays.

That is, for example, when the ultraviolet rays are irradiated for a plurality of times for a short time of about 0.1 second, the ultraviolet rays do not cure immediately and the viscosity increases. When it is irradiated with ultraviolet rays for about 60 seconds, it is completely cured.

Return light PR of the laser light PO emitted from the laser collimator 20 reflected from the PBS 3
Is more than a predetermined angle, the ultraviolet curable resin 22
Is radiated with the ultraviolet ray irradiating device 21 for a short time, for example, 0.1 seconds, and intermittently, for example, 2 to 3 times. The ultraviolet curing resin 22 is in a viscous state due to the ultraviolet rays that have passed through the PBS 3 during the irradiation time and the number of times, and in such a state, the PBS 3 can change its position (tilt) on the second moving holder 2. You can

That is, when the return light PR of the laser light PO emitted from the laser collimator 20 reflected from the PBS 3 is equal to or greater than a predetermined angle, for example, a jig shaped like a toothpick with a thin tip is used. Using the PB
Pressure is applied from a predetermined direction to the upper surface 5 of S3 (the surface on which the laser light PO emitted from the laser collimator 20 strikes),
The inclination of the PBS 3 is corrected while observing the return angle of the laser collimator 20 so that the return light PR reflected from the upper surface 5 of the PBS 3 is within a predetermined angle.

When the return light PR reflected from the upper surface 5 of the PBS 3 is within a predetermined angle, the ultraviolet irradiation device 21 continuously irradiates the ultraviolet light for 60 seconds, for example, and then the ultraviolet curable resin 22. To cure. As a result,
The PBS 3 is fixed to the second moving holder 2 to complete a polarization beam splitter with an optical axis adjusting mechanism.

Return light PR reflected from the PBS 3
Are reflected from the top surface 5 and the bottom surface 6 of the PBS 3. P
Although the upper surface 5 and the bottom surface 6 of the BS 3 are formed in parallel to each other, the light reflected from the upper surface 5 and the bottom surface 6 of the PBS 3 has a difference in optical path length, and one of the reflected lights reflects the laser collimator 20. It interferes with the measurement of the tilt used.

Therefore, either the surface of the PBS 3 in contact with the second movable holder 2, that is, the surface on which the ultraviolet curable resin 22 is applied, or the surface of the second movable holder 2 in contact with the bottom surface 6 of the PBS 3 is selected. The measurement accuracy may be improved by coating one or both of them with black.

[0039]

According to the method of manufacturing an optical component according to the first aspect of the present invention, an ultraviolet curable resin whose curing method changes depending on the irradiation conditions of ultraviolet rays is applied to the optical component, and the inclination of the optical component with respect to the reference plane is adjusted. By adjusting while using a laser collimator, it is not necessary to provide a new optical axis adjusting device outside the apparatus, and highly accurate optical parts can be manufactured with good workability.

According to the method of manufacturing an optical component of claim 2, the surface of the optical adjustment mechanism on which the optical component is mounted or the bottom surface of the optical component is blackened and adjusted by the laser collimator. It is possible to improve measurement accuracy and manufacture highly accurate optical components.

According to the method of manufacturing an optical component of claim 3, the ultraviolet rays are radiated obliquely from above so as to pass through the optical components and reach the bottom surface of the optical components. Can be irradiated, and efficient curing of the adhesive can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a PBS with an optical axis adjusting mechanism.

FIG. 2 is an explanatory diagram of a method of fixing a PBS mounted on a second moving holder without tilting.

[Explanation of symbols]

1st moving holder 2 Second moving holder 3 PBS 4 Adjustment jig 5 PBS top surface 6 Bottom of PBS 8 Optical axis adjustment mechanism 20 Laser collimator 21 UV irradiation device 21a, 21b UV irradiation part 21c, 21d optical fiber 22 UV curable resin 23 Reference plane

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03H 1/22 G02B 7/18 AF term (reference) 2H043 AD03 AD07 AD11 AD13 AD21 AE02 AE24 BA00 2H049 BA05 BB03 BB61 BC14 BC21 2K008 AA04 AA17 CC03 HH13

Claims (3)

[Claims] 1. A method of manufacturing an optical component by a manufacturing apparatus having a reference surface having a predetermined accuracy, a laser collimator, and an ultraviolet irradiation device, wherein the laser collimator is arranged above the reference surface, The laser collimator is adjusted so that the angle of the laser beam emitted from the laser collimator and returned to the laser collimator from the reference surface becomes zero, and the laser beam emitted from the laser collimator is below the laser collimator. An optical adjustment mechanism is installed on the reference surface so as to hit the optical component, and an optical component mounted thereon is installed, and a UV-curable resin is applied to the bottom surface of the optical component and reflected from the optical component. When the return light of the laser light emitted from the laser collimator is at a predetermined angle or more, the ultraviolet curing resin is irradiated with the ultraviolet light. A device briefly irradiates ultraviolet rays intermittently to cure the ultraviolet curable resin to a viscous state, and the return light of the laser light emitted from the laser collimator reflected from the upper surface of the optical component is a predetermined amount. Adjusting the inclination of the optical component so as to be within the angle, the return light of the laser light emitted from the laser collimator reflected from the upper surface of the optical component is within a predetermined angle, in the ultraviolet curing resin By continuously irradiating ultraviolet rays with the ultraviolet irradiating device to sufficiently cure the ultraviolet curable resin, the optical component is fixed to the optical adjusting mechanism to manufacture an optical component with an optical adjusting mechanism. Optical component manufacturing method. 2. A surface of an optical adjustment mechanism on which the optical component is mounted or a bottom surface of the optical component is made black to remove reflected light from a bottom portion of the optical component out of laser light emitted from the laser collimator. Then, the tilt of the optical component is adjusted by setting the reflected light from the upper surface of the optical component as the angle of the return light of the laser light emitted from the laser collimator,
The method of manufacturing an optical component according to claim 1, wherein an optical component with an optical adjustment mechanism is manufactured. 3. The optical device according to claim 1, wherein the ultraviolet light emitted from the ultraviolet irradiation device is emitted obliquely from above so as to reach the bottom surface of the ultraviolet light through the optical component. Manufacturing method of parts.