JP2001330743A - Optical parts, method for manufacturing the same and optical pickup using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rising mirror which is utilized for waveguides, etc., and a manufacturing method which is excellent in mass productivity of wavelength plates. SOLUTION: A poyimide layer and a reflection film 2 are deposited on a substrate 1 and the waveguide 4 and a mirror supporting layer 3 are formed by processing the poyimide layer. The mirror 7 is composed of the reflection 22 and the mirror supporting layer 3A and the substrate thereunder is etched by which the mirror 7 is arranged to incline diagonally in an opened recess 5. Light 6 propagating in the optical waveguide 4 is emitted in the normal direction of the substrate by the mirror 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical component, a method of manufacturing the same, and an optical pickup using the same, and more particularly, a rising mirror, a wave plate and the like used for light propagating in a direction parallel to a substrate surface. And an optical component using the same, and an optical pickup using the same.

[0002]

2. Description of the Related Art As a first conventional example of a rising mirror, for example, a mirror disclosed in Japanese Patent Application Laid-Open No. 10-206667 is known. FIG. 9 shows a method of manufacturing a rising mirror for an optical waveguide. First, on the substrate 41,
An optical waveguide core material 42 is formed, and an optical waveguide 43A, a gap 43B in which a mirror is arranged, and a support region 43C for supporting the mirror are formed, and a sacrifice layer 44 is buried flat in the gap 43B. Next, a mirror layer 45 is formed on the surface of the sacrifice layer 44, a support layer 46 is formed on the surface of the support region 43C, and a part of the mirror layer 45 and the support layer 46 are formed by a flexible polyimide thin film 47. connect. Finally, the sacrifice layer 44 is removed, and the mirror layer 45 is inclined obliquely in the gap after the removal to form a rising mirror for the guided light 48. As a second conventional example of the wave plate, for example, Japanese Patent Application Laid-Open
What is disclosed in -92326 is known.

FIG. 10 shows a single mode waveguide and a half mode waveguide.
2 shows a configuration of a polarization converter including a wave plate. Reference numeral 51 denotes an input waveguide, 52 denotes an output waveguide, 53 denotes a polyimide half-wave plate, 54 denotes a groove, and 55 denotes a silicon substrate. The optical waveguide is formed on a silicon substrate having a thickness of 1 mm by a flame deposition method and reactive ion etching, and has a size of 7 μm × 7.
It has a structure in which a μm core is embedded. The half-wave plate 53 is produced by uniaxially stretching a polyimide film and heat-treating the polyimide film so that an appropriate in-plane birefringence appears.

A groove 54 having a width of 20 μm and a depth of 150 μm is provided in the middle of the optical waveguide by using a dicing saw. A polyimide half-wave plate 53 is provided in the groove 54, and the optical axes of the substrates 55 and 45. It is inserted at an angle of degrees. When a horizontally polarized wave is incident on this polarization converter, a vertically polarized wave is emitted, and when a vertically polarized wave is incident, a horizontally polarized wave is emitted.

[0005]

However, in the method of the first conventional example, the mirror layer must be made considerably thick in order to secure the flatness of the mirror which is tilted obliquely, and it takes a long time to form a film. This requires a film formation time. Further, since the polyimide film used as the flexible thin film at the connection portion has poor adhesion to the metal film, it is considered that the support of the mirror becomes extremely unstable due to the peeling of the film due to the bending force. Further, there are many necessary steps such as embedding and flattening of a sacrificial layer, and formation of a flexible thin film supporting a mirror.
In particular, it is difficult to obtain sufficient specularity in the disclosed flattening process. Further, the method of the second conventional example is a method of combining a separately formed optical waveguide and a half-wave plate. However, since a minute wave plate must be inserted into a narrow groove, mass production is difficult. There was a problem.

One of the main objects of the present invention is to solve the above-mentioned problems, and to provide an optical component such as a mirror or a wave plate, which is excellent in structural stability and mass productivity, and a method of manufacturing the same, and a method of manufacturing the same. It is to provide an optical pickup used.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a substrate and a light-transmitting film formed on the substrate. Is further formed by etching a substrate portion below the island-shaped region to form a bottomed hole, and then the optical component is formed by bending the island-shaped region into the bottomed hole with the support.

That is, according to the present invention, an island region is formed by etching a light-transmitting film formed on a substrate, leaving a support portion in a part, and further etching a substrate portion below the island region. By forming a bottomed hole by bending the island-shaped region into the bottomed hole at the support portion, the optical component can be integrally formed only by etching and bending, thereby achieving structural stability. An optical component having excellent properties and mass productivity can be obtained.

In the present invention, the substrate and the light-transmitting film are not particularly limited, and those which can be generally used in this field can be used. For example, in the former, thermally oxidized silicon and quartz, in the latter, polyimide, PET ( Polyethylene terephthalate) is preferred.

Particularly preferred examples of the light-transmitting film include a polyimide-based film. Further, when flatness is required on the surface as in the present invention, the film thickness needs to be relatively thick, for example, 50 μm to 300 μm.
Is preferably set to. Hereinafter, in this specification, the term “optical thick film” or simply “thick film” means a light-transmitting film having such a thickness.

In the present invention, the substrate and the light transmitting film are formed into a desired shape by etching. That is, in the light transmitting film, an island region is formed by normal etching, leaving a part of the supporting portion. A bottomed hole is formed in the substrate by ordinary etching, particularly isotropic etching, except for at least the substrate portion below the island region.
The depth of the bottomed hole is preferably 30 to 200 μm. Then, the island-shaped region is bent from the support portion in the bottomed hole, and preferably, the island-shaped region is bonded with an adhesive (for example, epoxy,
It is fixed in the bottomed hole with an ultraviolet curing adhesive.

The optical component (or optical element) thus obtained can be used as a mirror, a wave plate or the like. In the case of a mirror, a reflective film portion is further formed on the island region. As the reflection film portion, a metal film (aluminum film, gold film, or the like), a dielectric multilayer film, or the like is used.

According to another aspect of the present invention, after forming a light-transmitting film on a substrate and etching the light-transmitting film to form an island-like region while leaving a support portion in part, Forming a bottomed hole by etching a substrate portion below the island-shaped region, and then bending the island-shaped region into the bottomed hole with the support to obtain an optical component; A fabrication method can be provided.

According to yet another aspect, the present invention comprises a substrate and a light-transmitting film formed on the substrate, and etching the light-transmitting film to leave an island with a support portion in part. Forming an open area, further etching the substrate portion below the island area to form a bottomed hole, and then bending the island area into the bottomed hole at the support portion,
A semiconductor laser that emits light, an objective lens that receives light from the semiconductor laser via the optical component, and condenses the light on an optical disk, and detects return light from the optical disk obtained through the objective lens An optical pickup comprising a photodetector that performs the above-described operations can be provided.

According to still another aspect of the present invention, there is provided a substrate comprising a substrate and a light-transmitting film formed on the substrate, and further comprising a depression (bottomed hole) extending from the light-transmitting film to the substrate. It is possible to provide an optical component having an inclined protruding portion, which has an inclined projection that is integrally inclined downward and protrudes downward from the light transmitting film on the side wall of the depression in the depression. Here, the inclined protruding portion is formed by connecting the light transmissive film portion integrally connected to the side wall of the depression to its root portion (support portion).
To be bent downward.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the optical component according to the present invention will be described below with reference to the drawings. FIG. 1A is a front view showing a first embodiment of the present invention, and FIG. 1B is an AA cross-sectional view thereof.

1 (a) and 1 (b), 1 is a substrate, 2 is a reflective film, 3A, 3B and 3C are mirror support layers,
4 is an optical waveguide. The mirror 7 is composed of a mirror support layer 3A and the reflective film 2 formed thereon, and is connected to the mirror support layer 3C via a constricted area 3B. The substrate 1 below the mirror 7 is engraved, and the mirror 7 is set in the recess 5 so as to be slanted. The angle of this fall depends on the depth of the depression 5 and the thickness of the mirror support layer 3A,
It can be adjusted by controlling the size. When this angle is 45 degrees, the light 6 propagating through the optical waveguide 4 can be emitted in the normal direction of the substrate surface. Or vice versa,
Light incident from the normal direction of the substrate surface can be coupled to the optical waveguide 4.

2 and 3 show a method of manufacturing a mirror according to a first embodiment of the present invention.
FIG. 3 is a process explanatory front view. First, as shown in FIG. 2A, a polyimide layer 8 is formed on a silicon wafer having an oxide film formed on the surface or a dielectric substrate such as a quartz substrate. The polyimide layer 8 is formed by applying a polyamic acid varnish by a spin coating method, an applicating method, or the like, and baking by heating. The thickness of the polyimide layer is, for example, 50
Set to about μm. The width is about 50 μm.
The polyimide layer 8 becomes a core material of the optical waveguide and a support layer of the mirror.

Next, as shown in FIG. 2B, the reflection film 2 is formed on a part of the polyimide layer 8. As the reflection film 2, a metal film or a dielectric multilayer film is used. On the polyimide layer 8, for example, an Al film is formed to a thickness of 0.2 μm by a vacuum evaporation method, an electron beam evaporation method, a sputtering method, or the like, and the reflection layer 2 is formed by patterning the Al layer by a normal photolithography method. . The reflection film 2 may be formed by a lift-off method. Since the underlying polyimide layer is flat and the Al layer may be thin, a good mirror surface can be obtained on the reflection surface.

Next, as shown in FIGS. 2C and 3A, the polyimide layer 8 is etched to form the optical waveguide 4 and the mirror support layer 3. The polyimide layer around the optical waveguide 4 and the mirror support layer 3 is removed by a method such as RIE or laser ablation. At the time of the processing, a thin polyimide layer is left in the constricted portion 3B of the mirror support layer (for example, a length of 20 mm × a depth of 10 μm is left over the entire width). In the case of laser ablation, the polyimide etching depth can be easily and partially controlled only by controlling the number of irradiation pulses. R
In the case of IE, photolithography and etching steps may be performed twice. Next, as shown in FIGS. 2D and 3B, a resist 9 is applied on the polyimide layer, exposed and developed, and an opening is provided around the mirror portion.

Next, as shown in FIGS. 2E and 3C, the substrate is wet-etched, and then the resist is removed. When the substrate is quartz, hydrofluoric acid is used. When the substrate is thermal silicon oxide, the oxide film on the surface is removed with hydrofluoric acid, and then the silicon is etched with a mixed solution of hydrofluoric acid and nitric acid. In the wet etching, since the etching proceeds isotropically, the substrate below the mirror 7 can also be etched, and the depression 5 as a bottomed hole is formed. The depth of the depression 5 is, for example, 40 μm, and is controlled by the shape of the resist opening and the etching time.

Although the mirror 7 falls into the recess 5, it is connected to the mirror supporting layer 3C via the mirror supporting layer 3B, so that the mirror supporting layer 3 having a thinner polyimide layer.
B is bent, and the mirror 7 falls down diagonally. The angle of the inclination is adjusted by controlling the depth of the depression 5 and the thickness and size of the mirror support layer 3A. Finally, the mirror 7 is bonded and fixed.

In the present invention, not only a simple mirror but also an optical element such as a Fresnel lens and a diffraction grating can be formed on a polyimide layer. The optical system can be further integrated by integrating the mirror, the Fresnel lens, and the diffraction grating. This can be manufactured by forming a diffraction grating on a polyimide layer, forming a reflective film, and etching the substrate. Alternatively, a dielectric film may be formed after forming a reflective film on the polyimide layer, and a diffraction grating may be formed on the dielectric film.

According to the method of manufacturing a mirror according to the embodiment, the following effects can be obtained. Since the reflection film is formed on the flat surface of the polyimide layer, a reflection surface with high planar accuracy can be obtained. In addition, since the reflection surface is supported by a polyimide layer as thick as several tens of μm, warping of the mirror can be suppressed even if the mirror is tilted obliquely.

Further, since only the formation of the polyimide layer and the reflection film is required, and the step of flattening the sacrificial layer and the step of forming the flexible thin film are unnecessary, the steps can be simplified. The process also includes film formation,
Since it is a combination of photolithography and etching technology, it has excellent reproducibility and mass productivity.

Further, since the mirror supporting layers 3a, 3B and 3C are made of the same material, and only the constricted portion 3B is thin and has sufficient flexibility, problems such as separation of the supporting layers hardly occur. Adhesion between the reflection film 2 and the mirror support layer 3A does not matter because no force is applied between the layers. FIG. 4 is a sectional view showing an embodiment of the second embodiment of the present invention.

This is an optical waveguide mirror similar to the first embodiment, but differs from the first embodiment in that reflection films are formed on two surfaces of the mirror support layer 3A. Reflection films 2 and 10 are formed on two surfaces of the mirror support layer 3A inclined by 45 degrees, and distribute the light 12 and 13 emitted from the optical fiber 11 and incident from the normal direction of the substrate in two directions. here,
The mirror support layer 3C also functions as a waveguide.

The manufacturing method is almost the same as that of the first embodiment, except that the reflection film is formed last. After etching the substrate and bending the polyimide layer,
By forming and patterning an Al film, the reflective films 2, 10 are formed.
To form

FIG. 5 is a perspective view showing an embodiment of the third embodiment of the present invention. FIG. 6A is a front view thereof, and FIG. 6B is a BB sectional view thereof. 1 is a substrate, 16A is a wave plate, 16B and 16C are wave plate support layers, 17 is an input waveguide, and 18 is an output waveguide. The wave plate 16A is formed of a uniaxially anisotropic polyimide layer made of an optically anisotropic material and having an optical principal axis in a direction perpendicular to the substrate.
It is connected to the wavelength plate supporting layer 16C via B. The substrate 1 of the wave plate 16A is engraved, and the wave plate 16A is installed in the depression 5 so as to be slanted. As shown in FIG. 6A, light passes through this wave plate in the direction of the arrow. When the product of the difference Δn between the in-plane refractive index n _TE and the surface normal direction refractive index n _TM of the polyimide layer and the thickness t of the wave plate is equal to 光線 or ４ of the light wavelength, 1/2 each
It functions as a wave plate and a quarter wave plate.

For example, if the polyimide is a fluorinated polyimide OPI-N2005 (manufactured by Hitachi Chemical), the refractive index difference Δn
Reaches 0.1, and a wavelength plate having a thickness t of 7.7 μm functions as a half-wave plate for light having a wavelength of 1.55 μm.

When the wavelength plate 16A is inserted between the single mode input waveguide 17 and the output waveguide 18 and the optical main axis is inclined at an angle of 45 degrees with the substrate surface, the horizontal polarization becomes vertical polarization. Vertical polarization can be exchanged for horizontal polarization. Wave plate 1
Since the thickness of 6A is as thin as several μm, the light emitted from the input waveguide 17 is again coupled to the output waveguide 18 with a small spread, so that the loss between the waveguides can be reduced.

If the tilt angle is 22.5 degrees, the plane of polarization can be rotated by 45 degrees. In an optical pickup for a magneto-optical disk, the polarization plane is set to 45 before detection of an optical signal.
This technique needs to be rotated by an angle, and this technique can be applied to an optical pickup for a magneto-optical disk.

When the thickness is 3.8 μm, the wavelength is 1.
It functions as a 波長 wavelength plate for 55 μm light. 1 /
When the four-wavelength plate is tilted so that the main optical axis forms an angle of 45 degrees with the substrate surface, horizontal polarization can be converted to circular polarization. For example, in an optical pickup optical system, a disk may be irradiated with circularly polarized light. However, by integrating a semiconductor laser and this wavelength plate, a small circularly polarized light emitting optical system can be easily configured.

The wave plate according to the third embodiment can be formed according to the manufacturing process of the first embodiment, omitting the manufacturing process of the reflection film. The input waveguide 17 and the output waveguide 18 are a wave plate 16
It is produced before the production of A. The material of the wave plate may be an optical film such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate), or may be a material having an optical principal axis in an in-plane direction.

Since the wave plate of the present invention can be manufactured only by the step of etching the polyimide layer and the substrate, the steps can be simplified, and the reproducibility and mass productivity are excellent. The angle of inclination of the wave plate can also be adjusted by the size of the wave plate and the depth of the depression.

Although the embodiment in which the mirror and the wavelength plate of the present invention are combined with a waveguide has been described, the present invention has been described with respect to the embodiment in which a light guide plate is combined with a waveguide, but the present invention uses a light guide plate. The present invention can also be applied to an optical system in which a bulk type micro optical component is arranged on a substrate.

FIG. 7 is a front view of a part of an integrated module of a magneto-optical pickup according to a fourth embodiment of the present invention, and FIG. 8 is a configuration diagram of the entire magneto-optical pickup.
However, the part of the integrated module is shown by the BB sectional view of FIG.

The integrated module 21 includes a semiconductor laser 22, a grating 23, a hologram 24,
1/2 wavelength plate 25, polarizing prism 26, 45 degree mirror 2
7 and 28 and photodiodes 29 and 30 are integrated. Photodiodes 29 and 30 are formed on the substrate 1. Optical elements other than the semiconductor laser 22 on the substrate 1 are formed by processing a uniaxial optical thick film having an optical axis in the surface normal direction and formed on the substrate.

The grating 23 is formed by processing a support layer 23a formed by processing an optical thick film, a reflective film 23b formed thereon, and further processing a dielectric film formed thereon. It is formed by the same manufacturing method as in the first embodiment, and is inclined by 45 degrees from the substrate surface. The hologram 24 also includes a support layer 24a, a reflection film 24b, and a hologram layer 24c, and is manufactured by the same method as the grating. The half-wave plate 25 is tilted so that the optical axis forms an angle of 22.5 degrees with the substrate surface normal, and is manufactured by the same manufacturing method as in the third embodiment.

Further, a polarizing prism 26 having a triangular prism shape, and 45-degree mirrors 27 and 28 having a surface forming 45 degrees with the substrate surface.
Is formed by processing the optical thick film. A polarizing prism 26 formed of an anisotropic optical thick film divides incident light into polarized light having a plane of polarization parallel to the substrate surface and polarized light having a plane of perpendicular polarization. The 45-degree mirrors 27 and 28 having a 45-degree surface formed by laser ablation scanning process bend light traveling parallel to the substrate surface by 90 degrees and guide the light to the photodiode. After forming these optical elements, the semiconductor laser 22 is die-bonded to produce the integrated module 21.

The light beam 35 emitted from the semiconductor laser 22 is split into three beams by the grating 23 inclined at 45 degrees from the substrate surface, and rises in the normal direction of the substrate surface. The two sub-beams generated here are used for generating a tracking error signal. Further, the light passes through a beam splitter 31 and a collimating lens 32 and is condensed on a magneto-optical disk 34 as a record carrier by an objective lens 33.

The light reflected by the magneto-optical disk 34 passes through the objective lens 33, the collimator lens 32, and the beam splitter 31, and is guided to the hologram 24 inclined at 45 degrees from the substrate surface. The hologram 24 is divided into two, and the holograms have different grating pitches. The light 37 diffracted by the hologram travels in a direction parallel to the substrate surface, passes through the half-wave plate 25, and is guided to the photodiode 30 via the 45-degree mirror.
The photodiode 30 is divided into several parts. Light incident on each photodiode is converted into an electric signal, and a focusing error signal is detected from the signal.

On the other hand, the zero-order light 36 of the hologram is guided to the photodiode 29 via the half-wave plate 25, the polarizing prism 26, and the 45-degree mirror 27. The photodiode 29 is also divided into several parts, and a magneto-optical signal and a tracking error signal are detected from each signal.

The light applied to the magneto-optical disk 34 is a polarized light having a plane of polarization parallel to the substrate surface.
Rotate 2 °. In order to effectively detect the amount of rotation, it is necessary to detect polarized light having a component inclined by ± 45 ° with respect to the polarization plane of the light focused on the magneto-optical disk 34. Here, the polarization plane is set to 45 by the half-wave plate 25.
Then, the light is separated by the polarizing prism 26 into polarized light having a plane of polarization perpendicular to the substrate surface and a plane of polarization parallel to the substrate surface. The magneto-optical signal is detected by calculating the difference between the two polarization intensities. Further, the tracking error signal is detected from the difference in intensity between the two sub beams.

In this embodiment, the hologram, the grating, the half-wave plate, and the polarizing prism can be formed at once by a semiconductor process, and the position adjustment is not required. Semiconductor laser,
By integrating the photodiode, the size and weight of the optical pickup can be significantly reduced.

As described above, since the optical component of the present invention can be formed by a combination of photolithography and etching technology, it is extremely excellent in reproducibility and mass productivity. Since the mirror is composed of a support layer having a flexible constricted portion and a reflective film, the support is stable. Further, since the surface of the support layer is smooth and the support layer is thick and does not warp when the support layer is tilted, the flatness of the reflection surface can be kept high. Since the number of processes is small, productivity is excellent.

The wave plate is manufactured using an optical thick film having birefringence. Since the wave plate is formed only by processing the optical thick film and the substrate, and the inclination angle of the wave plate can be adjusted by the size and the depth of the depression, the position adjustment and the inclination adjustment of the wave plate are unnecessary and the mass productivity is excellent.

Since these optical parts can be manufactured using various kinds of polymer materials which can easily form a thick film, the optical parts have a high degree of freedom in function and a low film formation cost. When a waveguide, a light guide plate, and a micro optical component are made of the same material, a plurality of optical components having different functions can be manufactured at one time, and integration of an optical system can be achieved.

[0049]

According to the present invention, the light-transmitting film formed on the substrate is etched to form an island-like region while leaving a support portion in a part, and the substrate portion below the island-like region is further formed. By etching to form a bottomed hole, and then bending the island region into the bottomed hole at the support, the optical component can be integrally formed only by etching and bending, thereby providing a structural advantage. An optical component having excellent stability and mass productivity can be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B show a first embodiment of an optical component according to the present invention, wherein FIG. 1A is a front view, and FIG.

FIG. 2 is a process explanatory cross-sectional view for explaining a manufacturing method according to the first embodiment of the present invention.

FIG. 3 is a process explanatory front view illustrating a manufacturing method according to the first embodiment of the present invention.

FIG. 4 is a sectional view of a second embodiment of the present invention.

FIG. 5 is a perspective view showing a configuration of a third embodiment of the present invention.

FIGS. 6A and 6B show a third embodiment of the present invention, wherein FIG. 6A is a front view thereof, and FIG.

FIG. 7 is a front view showing a configuration of a fourth embodiment of the present invention.

FIG. 8 is a configuration explanatory view showing a configuration of a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a manufacturing method of a first conventional example.

FIG. 10 is a front view showing a configuration of a second conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2, 10 Reflection film 3 Mirror support layer 4 Waveguide 7 Mirror 16A Wave plate 16B, 16C Wave plate support layer 17 Input waveguide 18 Output waveguide 22 Semiconductor laser 23 Grating 24 Hologram 25 1/2 wavelength plate 26 Polarizing prism 27, 28 45-degree mirror 29, 30 Photodiode 31 Beam splitter 32 Collimating lens 33 Objective lens 34 Magneto-optical disk

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 7/22 G02B 6/12 C 5F089 H01L 31/0232 B 31/12 M H01L 31/02 DF term ( Reference) 2H042 DA01 DA08 DA11 DC02 DC08 DD00 DE00 2H047 KA03 LA09 MA07 PA21 PA24 QA05 RA04 TA05 TA43 2H049 BA07 BA08 BB36 BB44 BC01 BC21 5D119 AA02 AA38 BA01 CA10 FA36 JA57 JC05 LB07 NA05 5F011 JA18 BB01 JA18 BB07 BC22 BC23 BC24 BC25 CA20 GA01 GA03 GA05

Claims (9)

[Claims] 1. A substrate and a light-transmitting film formed on the substrate, the light-transmitting film is etched to form an island-like region while leaving a support part in a part, and further comprising the island-like region. An optical component formed by etching a substrate portion below a region to form a bottomed hole, and then bending the island region into the bottomed hole at the support. 2. The optical component according to claim 1, further comprising a reflection film portion formed on the island region, and a mirror formed by the reflection film portion and the island region. 3. A mirror according to claim 1, wherein the direction of light travels in a direction parallel to the substrate surface from a direction normal to the substrate surface and in a direction transmitting the light-transmitting film.
3. The optical component according to claim 2, wherein the conversion is performed in reverse. 4. The optical component according to claim 1, wherein the light-transmitting film is made of an optically anisotropic material having an optical axis in a direction parallel or perpendicular to the substrate surface. 5. The optical component according to claim 1, wherein the optical component is a wave plate. 6. The optical component according to claim 1, wherein the angle of inclination of the bent island region with respect to the horizontal is 45 degrees or less. 7. A light-transmitting film is formed on a substrate, and the light-transmitting film is etched to form an island-like region while leaving a supporting portion in a part, and then the substrate portion below the island-like region is formed. Forming a bottomed hole by etching the substrate, and then bending the island-shaped region into the bottomed hole at the support portion to obtain an optical component. 8. The method for manufacturing an optical component according to claim 7, wherein the island-shaped region bent in the bottomed hole is adhered and fixed to the bottom of the bottomed hole. 9. An island-shaped region comprising a substrate and a light-transmitting film formed on the substrate, etching the light-transmitting film to leave a support portion in a part, and further forming the island-shaped region. An optical component formed by etching a substrate portion below the region to form a bottomed hole, and then bending the island region into the bottomed hole with the support, a semiconductor laser emitting light, An optical pickup comprising: an objective lens that receives light from a laser via the optical component and condenses the light on an optical disk; and a photodetector that detects return light from the optical disk obtained through the objective lens.