JP2007115300A - Optical element, optical pickup device, and manufacturing method of optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element wherein accuracy of a reflection surface is improved. <P>SOLUTION: The optical element is characterized in that a first multilayered film transmitting or reflecting light is formed between base bodies made of a light transmission medium, a groove is provided in the base bodies along a direction nearly orthogonal to the first multilayered film, a second multilayered film transmitting or reflecting light is inserted in the groove and a gap between the second multilayered film and the groove is filled up with an adhesive. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical element that reflects light having a plurality of wavelengths, an optical pickup device including the optical element, and a method for manufacturing the optical element.

  2. Description of the Related Art In recent years, in an optical pickup device used for recording / reproducing information with respect to an optical disc having a recording density increased by using a blue laser beam having a wavelength of about 400 nm and a large storage capacity, a conventional DVD (Digital Versatile Disk) or CD (Compact There is a strong demand for media compatibility that is compatible with disk (red) and near-infrared laser light. However, optical elements such as prisms for combining and branching the optical path of laser light are used for recording / reproducing information on the optical disk and detecting signals by the return light from the optical disk. An optical element such as a prism is provided for each wavelength, which increases the size of the apparatus.

In order to solve this problem, various prisms have been proposed conventionally. For example, Patent Documents 1 and 2 disclose a dichroic prism in which four triangular prisms having the same shape are bonded to each other in order to branch and synthesize light having a plurality of wavelengths.
JP-A-8-184798 JP-A-10-311907

  However, since the dichroic prisms described in Patent Documents 1 and 2 constitute a reflective surface by bonding four prisms, a reflective surface that splits and synthesizes light by causing a step or inclination on the reflective surface. Are difficult to make on the same plane and cannot be manufactured with the accuracy required by an optical pickup device or the like.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a small-sized optical pickup device that has a high accuracy of the reflecting surface of an optical element such as a prism, can be easily manufactured, and is inexpensive. And

  The above problem is solved by the following configuration.

(1) first and second substrates made of a light-transmitting medium;
First and second multilayer films that transmit or reflect light, and
The first multilayer film that transmits or reflects light is formed on the bonding surface between the first base and the second base, and
A groove is formed in the first base and the second base in a direction substantially orthogonal to the bonding surface on which the first multilayer film is formed;
An optical element, wherein the second multilayer film is inserted into the groove, and a light-transmitting adhesive is filled in a gap between the second multilayer film inserted into the groove.

  (2) Each of the first and second substrates has a right triangle in cross section, and each has the same refractive index, and is on the hypotenuse surface of the right triangle of the first substrate or the second substrate. The optical element according to (1), wherein the optical element is a prism on which the first multilayer film is formed.

(3) When the width of the groove is a and the unit is mm,
0.05 <a <0.2
The optical element according to (1) or (2), wherein

  (4) The optical element according to any one of (1) to (3), wherein the first and second bases are made of glass.

  (5) The optical element according to any one of (1) to (4), wherein the adhesive is an ultraviolet curable resin.

  (6) The first multilayer film transmits blue light and polarizes and separates red or infrared light, and the second multilayer film polarizes and separates blue light and transmits red or infrared light. The optical element according to any one of (1) to (5), wherein:

(7) a plurality of laser light sources having different wavelengths;
The optical element according to (6), which transmits and reflects laser light with respect to the wavelength of each laser light source;
A wave plate for changing the phase of laser light emitted from the optical element;
An optical pickup device comprising: an objective lens that condenses the laser light that has passed through the wave plate on an optical recording surface of a disk medium.

(8) a laser light source that emits light of different wavelengths;
The optical element according to (6), which transmits and reflects laser light with respect to different wavelengths of the laser light source;
A wave plate for changing the phase of laser light emitted from the optical element;
An optical pickup device comprising: an objective lens that condenses the laser light that has passed through the wave plate on an optical recording surface of a disk medium.

(9) preparing a parallel flat plate made of a plurality of light-transmitting media in which a first multilayer film that transmits or reflects light is formed on one surface;
Laminating the parallel flat plates in a direction in which the first multilayer film is parallel, and bonding the parallel flat plates with a first translucent adhesive to form a laminate;
Cutting the laminated body along a direction parallel to the first multilayer film at a predetermined pitch in a direction perpendicular to the first multilayer film to form a plurality of laminated divided bodies;
Forming a plurality of grooves parallel to each other at a predetermined pitch in a direction orthogonal to the first multilayer film on one side of the cut surface of the multilayer divided body;
A second multilayer film that transmits or reflects light is inserted into the groove, and a light-transmitting property is formed in the gap between the groove and the second multilayer film that is generated when the second multilayer film is inserted into the groove. Forming a cross film forming body in which the first multilayer film and the second multilayer film intersect in a cross shape;
The cross film forming body is inclined at 45 degrees with respect to the first multilayer film 222a at a predetermined pitch from the intersection where the first multilayer film and the second multilayer film intersect in a cross shape with the first cutting direction as the first cutting direction. Cutting and forming a plurality of elongated bodies;
Cutting the long body at a predetermined pitch in a direction perpendicular to the first cutting direction and separating the long body into individual optical elements;
An optical element manufacturing method comprising:

  In the present invention, a first multilayer film that transmits or reflects light is formed between bases made of a translucent medium, grooves are formed in the base in a direction substantially perpendicular to the first multilayer film, By inserting a second multilayer film that transmits or reflects light and filling the gap between the second multilayer film and the groove with an adhesive, the reflective surface of the optical element can be easily manufactured with high accuracy. An inexpensive and small optical element, an optical pickup device, and an optical element manufacturing method can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a configuration of an optical pickup device equipped with an optical element according to the present invention. The optical pickup apparatus 1 includes a first disk medium (Blu-ray disk) compatible with a blue laser (wavelength 405 nm) and a second disk medium (DVD) compatible with a red laser (wavelength 650 nm) or an infrared laser (wavelength 780 nm). ) Is a two-wavelength optical pickup device capable of recording / reproducing optical information to / from any one of the third disk media (CD).

  The optical pickup device 1 includes, as semiconductor laser light sources, a first light source 10X that emits laser light having a wavelength of 405 nm and a second light source 10Y that emits laser light having a wavelength of 650 nm or laser light having a wavelength of 780 nm. One of the two laser light sources 10X and 10Y is turned on according to the difference in substrate thickness of the disk medium, and optical information is recorded or reproduced on the optical recording surface.

  A description will be given along the optical path of each laser beam. First, laser light LX having a wavelength of 405 nm emitted from the first light source 10X is incident on the prism 20 after being beam-shaped and collimated, although not shown.

  The first multilayer film 22a of the prism 20 is configured to transmit blue light having a wavelength of 395 nm to 415 nm, and to polarize and separate red or infrared light having a wavelength of 640 nm to 800 nm, and is emitted from the first light source 10X. The laser beam LX to transmit is transmitted.

  The second multilayer film 22b of the prism 20 is arranged in a direction orthogonal to the first multilayer film 22a, and polarization-separates blue light having a wavelength of 395 nm to 415 nm, and red or infrared light having a wavelength of 640 nm to 800 nm. It has a configuration of transmitting light, and has a polarization separation function of reflecting the laser beam LX having a polarization direction emitted from the first light source 10X and transmitting the laser beam LX having a polarization direction perpendicular thereto.

  Therefore, the laser light LX emitted from the first light source 10X passes through the first multilayer film 22a and is reflected by the second multilayer film 22b.

  The laser beam LX emitted from the prism 20 is converted in phase by the quarter-wave plate 30 to become circularly polarized light, and enters the disk substrate 50 through the objective lens 40. The objective lens 40 forms an image of the laser beam LX on the optical recording surface of the disk substrate 50, and performs writing (recording), reading (reproducing), erasing and the like of information on the disk medium.

  Return light from the disk substrate 50 enters the objective lens 40 and the quarter-wave plate 30. In the quarter wavelength plate 30, the polarization direction of the laser light LX is converted into a direction perpendicular to the laser light LX emitted from the first light source 10X. The laser beam LX whose polarization direction has been converted enters the prism 20 and passes through the first multilayer film 22a and the second multilayer film 22b. The laser beam LX emitted from the prism 20 is collected and enters a photodetector 60 that is a photodiode. The photodetector 60 detects signals from the optical recording surface of the disk medium.

  Next, a case where the laser light source emits laser light having a wavelength of 650 nm or 780 nm will be described. First, the laser light LY having a wavelength of 650 nm or 780 nm emitted from the second light source 10Y is incident on the prism 20 after being beam-shaped and collimated, although not shown.

  The first multilayer film 22a of the prism 20 has a polarization separation function of reflecting the laser beam LY having a polarization direction emitted from the second light source 10Y and transmitting the laser beam LX having a polarization direction perpendicular thereto. .

  The second multilayer film 22b of the prism 20 has a function of transmitting the laser light LX emitted from the second light source 10Y.

  Therefore, the laser beam LY emitted from the second light source 10Y passes through the second multilayer film 22b and is reflected by the first multilayer film 22a.

  The laser beam LY emitted from the prism 20 is converted in phase by the quarter-wave plate 30 to become circularly polarized light, and enters the disk substrate 50 through the objective lens 40. The objective lens 40 forms an image of the laser beam LY on the optical recording surface of the disk substrate 50, and performs writing (recording), reading (reproducing), erasing and the like of information on the disk medium.

  Return light from the disk substrate 50 enters the objective lens 40 and the quarter-wave plate 30. In the quarter wavelength plate 30, the polarization direction of the laser light LY is converted into a direction perpendicular to the laser light LY emitted from the second light source 10Y. The laser beam LY whose polarization direction has been converted enters the prism 20 and passes through the first multilayer film 22a and the second multilayer film 22b. The laser beam LY emitted from the prism 20 is condensed and enters the photodetector 60 that is a photodiode. The photodetector 60 detects signals from the optical recording surface of the disk medium.

  As described above, in the optical pickup device corresponding to a plurality of laser light sources, the two films 22a and 22b for selecting and splitting the wavelength of the laser light source are formed on the prism 20, so that each laser light source has a prism or the like. There is no need to dispose an optical element, and the optical pickup device can be reduced in size.

  Next, the configuration of the prism 20 will be described with reference to FIG. FIG. 2A is a plan view of the prism 20, and FIG. 2B is a side view. The prism 20 has a rectangular parallelepiped shape having a square surface.

  The first base 21a has a right-angled isosceles triangular prism shape and is a glass made of a light-transmitting medium. The first multilayer film 22a is formed on the oblique side of the right-angled isosceles triangle, and the second base 21b is , Is a right isosceles triangular prism shape having the same size as the first substrate 21a, and is made of a transparent medium having the same refractive index and dispersion as the first substrate 21a, and is formed through the first multilayer film 22a. 1 is bonded to one base 21a.

  The groove 23 is formed in a direction perpendicular to the first multilayer film 22a on the square surface of the prism 20 as shown in FIG. 2A in a state where the first base 21a and the second base 21b are bonded. 2 to the position indicated by the wavy line in FIG. 2B is provided by dicing. It is provided for inserting the second multilayer film 22b in the combined state of the first base 21a and the second base 21b.

  The width a of the groove 23 is an appropriate range of 0.05 mm <a <0.2 mm. The range of the groove width a is to ensure the optical characteristics of the film inserted into the groove while processing the groove flat. is there.

  If the value of the groove width a exceeds the lower limit value, dicing processing becomes difficult, the flatness of the groove is lowered, and it becomes difficult to insert the second multilayer film 22b. On the contrary, if the value of the groove width a exceeds the upper limit value, the gap between the second multilayer film 22b and the groove 23 increases, and the amount of laser light reflected and transmitted by the films 22a and 22b decreases. The imaging performance of the optical recording surface is disturbed.

  The configuration of the first multilayer film 22a and the second multilayer film 22b will be described with reference to FIGS. FIG. 3A shows the spectral characteristics of the first multilayer film 22a, and FIG. 3B shows the spectral characteristics of the second multilayer film 22b. 3A and 3B, the vertical axis indicates the reflectance (R), the horizontal axis indicates the wavelength (λ), the wavelength 405 nm of the first light source 10X is indicated by X, and the second axis The wavelength 650 nm of the light source 10Y is indicated by Y1, and the wavelength 780 nm is indicated by Y2. The solid line indicates the spectral characteristic of the S wave, and the broken line indicates the characteristic of the P wave whose polarization direction is perpendicular to the S wave.

  As shown in FIG. 3A, the first multilayer film 22a transmits blue light having a wavelength from 395 nm to 415 nm including the first light source 10X, and has a wavelength from 640 nm to 800 nm including the second light source 10Y. In this configuration, the red or infrared light is polarized and separated.

  As shown in FIG. 3B, the second multilayer film 22b polarization-separates blue light having a wavelength of 395 nm to 415 nm including the first light source 10X, and 640 nm to 800 nm including the second light source 10Y. In this configuration, red or infrared light having a wavelength is transmitted.

  The second multilayer film 22b is formed on the transparent substrate 25 having the same refractive index and dispersion as the bases 21a and 21b. Instead of forming a film on the substrate 25, the second multilayer film 22b is formed on a glass substrate on which silver is vapor-deposited, and then the silver on the glass substrate is dissolved and separated from the glass substrate. In the reflection and transmission of light, it is possible to further suppress the decrease in the amount of light and the disturbance of image formation.

  As described above, the optical element used in the prism 20 of the present invention has a configuration in which the first multilayer film 22a is formed on the inclined surface of the triangular prism of the base 21b, and the reflecting surface is formed by branching and combining the laser beams. Since the second multilayer film 22b is inserted into the groove 23 provided by the groove processing on the bonded bases 21a and 21b, and the laser beam is branched and synthesized, the reflection surface is formed. And a highly accurate reflective surface can be obtained.

  Further, since the second multilayer film 22b of the prism 20 is configured to polarization-separate short-wavelength light including the first light source 10x and form an image on the optical recording surface of the disk substrate 50, more accurate imaging performance. Is obtained.

  Next, a method for manufacturing the prism 20 shown in FIG. 2 will be described with reference to the steps shown in FIGS.

  First, in the step of FIG. 4A, a plurality of glass parallel plates 210 are prepared, and a first multilayer film 222 a having a polarization separation function is formed on one surface of the parallel plates 210.

  In the step of FIG. 4B, the first multilayer film 222a is aligned upward, a plurality of parallel flat plates 210 are stacked in parallel, and the side surfaces of the parallel flat plates 210 are pressed against the flat surface 221 of the holder 220 to be aligned. In this state, the laminated body 211 is formed by bonding the surface on which the first multilayer film 222a is formed with a first adhesive. The first adhesive is a photo-curing adhesive having substantially the same refractive index as that of the parallel plate 210. Furthermore, the first adhesive is preferably an ultraviolet curable adhesive that is insoluble in a solvent.

  In the step of FIG. 4C, the stacked body 211 is cut along a plurality of parallel first cutting directions (see the alternate long and short dash line a) at a predetermined pitch in a direction orthogonal to the first multilayer film 222a. A plurality of stacked division bodies 212 (see FIG. 4C ′) is formed.

  Next, in the process of FIG. 5A, a plurality of parallel lines are formed at the same pitch as the pitch of the first multilayer film 222a along the direction orthogonal to the first multilayer film 222a in parallel with the cut surface of the multilayer divided body 212. The groove 223 is formed to the depth indicated by the wavy line in the left figure. In order to form the groove 223, dicing or etching is preferable.

  5B, the second multilayer film 222b having a polarization separation function is inserted into the groove 223 formed in the process of FIG. 5A, and the groove 223 and the second multilayer film 222b are formed. A second adhesive is sealed in the gap to form a cross film forming body 213.

  The second multilayer film 222b is formed on a substrate having substantially the same refractive index and dispersion as the parallel plate 210. Instead of forming a film on the substrate, the second multilayer film 222b may be formed on a glass substrate on which silver is vapor-deposited, and then the silver on the glass substrate is dissolved and separated from the glass substrate. Good.

  The second adhesive is an ultraviolet curable adhesive having substantially the same refractive index as that of the parallel plate 210. Further, the second adhesive is preferably an anaerobic ultraviolet curable adhesive. With an anaerobic ultraviolet curable adhesive, the adhesive protruding from the groove 223 is not cured and is easy to remove. The second adhesive may be the same as the first adhesive.

  Next, in the process of FIG. 6A, the first multilayer film 222a is formed at a predetermined pitch from the intersection where the first multilayer film 222a and the second multilayer film 222b intersect in a cross shape. Are cut along a second cutting direction (see the alternate long and short dash line b) inclined by 45 degrees to form a plurality of elongated bodies 214 (see FIG. 6 (A ′)).

  Further, the cut surface of the long body 214 is polished on both sides. The polishing here is, for example, lapping polishing. Although both sides may be polished one by one without simultaneously polishing both sides, double-side polishing is more efficient and preferable.

  6B, the long body 214 is cut at a predetermined pitch along a direction orthogonal to the second cutting direction (see the alternate long and short dash line c), and the first film 222a and the second film The membrane 22b is separated into individual elements so that it crosses the cross. Furthermore, the cut surface of the element is polished on both sides. The polishing here is, for example, lapping polishing. Although both sides may be polished one by one without simultaneously polishing both sides, double-side polishing is more efficient and preferable.

In the process of FIG. 6C, the prism 20 is completed.
The target prism 20 is obtained through the above steps.

  Note that the prism 20 of the present invention can be mounted on the optical pickup device of the second embodiment instead of the optical pickup device of the first embodiment of FIG. FIG. 7 shows the second embodiment, which is an optical pickup device having a plurality of photodetectors that emit light of different wavelengths from one laser light source and receive light corresponding to each wavelength. In addition, the same number is attached | subjected to the member of the same function as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  The optical pickup device includes a light source 10 that selectively emits laser light having a wavelength of 405 nm and laser light having a wavelength of 650 nm or laser light having a wavelength of 780 nm as a semiconductor laser light source. Depending on the difference in substrate thickness of the disk medium, one of the two wavelengths is emitted, and optical information is recorded or reproduced on the optical recording surface.

  The light source 10 is arranged to be rotated by 90 degrees with respect to the first embodiment, and the vibration direction of the laser light of each wavelength is converted by 90 degrees, and a P wave is emitted from the light source 10.

  First, laser light having a wavelength of 405 nm emitted from the light source 10 is incident on the prism 20 after being beam-shaped and collimated (not shown). The laser light incident on the prism 20 is transmitted through the first multilayer film 22a, and the second multilayer film 22b transmits the P wave, so that the laser light is transmitted through the second multilayer film 22b.

  The laser beam emitted from the prism 20 is converted into a circularly polarized light by being phase-converted by the quarter-wave plate 30, enters the disk substrate 50 through the objective lens 40, and writes (records), reads (reproduces) information. Erase etc.

  Return light from the disk substrate 50 enters the objective lens 40 and the quarter-wave plate 30. In the quarter-wave plate 30, the polarization direction of the laser light is converted into an S wave. The laser beam converted into the S wave is incident on the prism 20, passes through the first multilayer film 22a, and is reflected by the second multilayer film 22b. The laser light emitted from the prism 20 is condensed and enters a photodetector 60X that detects light having a wavelength of 405 nm. In the photodetector 60X, signal detection from the optical recording surface of the disk medium is performed.

  In the case where the laser light source emits a laser beam having a wavelength of 650 nm or 780 nm, although not shown, the beam is shaped and collimated and then incident on the prism 20, and the laser beam incident on the prism 20 is the first multilayer film. Since 22a transmits the P wave, it passes through the first multilayer film 22a and passes through the second multilayer film 22b.

  The laser beam emitted from the prism 20 is converted into a circularly polarized light by being phase-converted by the quarter-wave plate 30, enters the disk substrate 50 through the objective lens 40, and writes (records), reads (reproduces) information. Erase etc.

  Return light from the disk substrate 50 enters the objective lens 40 and the quarter-wave plate 30. In the quarter-wave plate 30, the polarization direction of the laser light is converted into an S wave. The laser light converted into the S wave is incident on the prism 20, passes through the second multilayer film 22b, and is reflected by the first multilayer film 22a. The laser light emitted from the prism 20 is condensed and enters a photodetector 60Y that detects light having a wavelength of 650 nm or 780 nm. The photodetector 60Y detects signals from the optical recording surface of the disk medium.

  Further, the spectral characteristics of the first multilayer film 22a and the second multilayer film 22b can be replaced. That is, the first multilayer film 22a polarization-separates blue light having a wavelength of 395 nm to 415 nm and transmits red or infrared light having a wavelength of 640 nm to 800 nm, and the second multilayer film has a wavelength of 395 nm to 395 nm. A configuration may be adopted in which blue light having a wavelength of up to 415 nm is transmitted and red or infrared light having a wavelength of from 640 nm to 800 nm is polarized and separated.

The figure which shows the structure of the optical pick-up apparatus using the prism concerning this invention. The figure which shows the structure of the prism concerning this invention. The figure which shows the spectral characteristics of the 1st multilayer film of this invention, and a 2nd multilayer film. The figure which shows the pre-process of the manufacturing method of the optical element concerning this invention. The figure which shows the intermediate process of the manufacturing method of the optical element concerning this invention. The figure which shows the post process of the manufacturing method of the optical element concerning this invention. The figure which shows the structure of the optical pick-up apparatus of 2nd Embodiment using the prism concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical pick-up apparatus 10 Light source 10X 1st light source 10Y 2nd light source 20 Prism 21a 1st base | substrate 21b 2nd base | substrate 22a 1st multilayer film 22b 2nd multilayer film 23 Groove 25 Substrate 30 Wavelength plate 40 Objective lens 50 disk substrate 60, 60X, 60Y photodetector 210 parallel plate 211 laminated body 212 laminated divided body 213 cross film forming body 214 long body 222 film

Claims (9)

First and second substrates made of a translucent medium;
First and second multilayer films that transmit or reflect light, and
The first multilayer film that transmits or reflects light is formed on the bonding surface between the first base and the second base, and
A groove is formed in the first base and the second base in a direction substantially orthogonal to the bonding surface on which the first multilayer film is formed;
An optical element, wherein the second multilayer film is inserted into the groove, and a light-transmitting adhesive is filled in a gap between the second multilayer film inserted into the groove. Each of the first and second substrates has a right triangle in cross section, and each has the same refractive index, and the first and second substrates have the same refractive index, and the first and second substrates have the first triangle on the hypotenuse surface of the right triangle. The optical element according to claim 1, wherein the optical element is a prism having a multilayer film formed thereon. When the width of the groove is a and the unit is mm,
0.05 <a <0.2
The optical element according to claim 1, wherein the optical element is an optical element. The optical element according to any one of claims 1 to 3, wherein the first and second bases are made of glass. The optical element according to any one of claims 1 to 4, wherein the adhesive is an ultraviolet curable resin. The first multilayer film transmits blue light and polarizes and separates red or infrared light, and the second multilayer film polarizes and separates blue light and transmits red or infrared light. The optical element according to any one of claims 1 to 5. A plurality of laser light sources having different wavelengths;
The optical element according to claim 6, which transmits and reflects laser light with respect to the wavelength of each laser light source;
A wave plate for changing the phase of laser light emitted from the optical element;
An optical pickup device comprising: an objective lens that condenses the laser light that has passed through the wave plate on an optical recording surface of a disk medium. A laser light source that emits light of different wavelengths;
The optical element according to claim 6, which transmits and reflects laser light with respect to different wavelengths of the laser light source;
A wave plate for changing the phase of laser light emitted from the optical element;
An optical pickup device comprising: an objective lens that condenses the laser light that has passed through the wave plate on an optical recording surface of a disk medium. Preparing a parallel flat plate made of a plurality of light-transmitting media in which a first multilayer film that transmits or reflects light is formed on one surface;
Laminating the parallel flat plates in a direction in which the first multilayer film is parallel, and bonding the parallel flat plates with a first translucent adhesive to form a laminate;
Cutting the laminated body along a direction parallel to the first multilayer film at a predetermined pitch in a direction perpendicular to the first multilayer film to form a plurality of laminated divided bodies;
Forming a plurality of grooves parallel to each other at a predetermined pitch in a direction orthogonal to the first multilayer film on one side of the cut surface of the multilayer divided body;
A second multilayer film that transmits or reflects light is inserted into the groove, and a light-transmitting property is formed in the gap between the groove and the second multilayer film that is generated when the second multilayer film is inserted into the groove. Forming a cross film forming body in which the first multilayer film and the second multilayer film intersect in a cross shape;
The cross film forming body is inclined at 45 degrees with respect to the first multilayer film 222a at a predetermined pitch from the intersection where the first multilayer film and the second multilayer film intersect in a cross shape with the first cutting direction as the first cutting direction. Cutting and forming a plurality of elongated bodies;
Cutting the long body at a predetermined pitch in a direction perpendicular to the first cutting direction and separating the long body into individual optical elements;
An optical element manufacturing method comprising:

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