JP2006220773A - Method of manufacturing optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a method of manufacturing optical elements by which the forming steps of an antireflection film can be cut into half and the formation of a failure such as yellowing or haze in the antireflection film is suppressed. <P>SOLUTION: The method of manufacturing the optical elements comprises the steps of: preparing a plurality of parallel flat plates made of glass on one surface of each of which a light separation film is formed; forming a laminated body by adhering the parallel flat plates by using a first transparent adhesive; cutting the laminated body at a prescribed pitch along a plurality of parallel first cutting directions (a)inclined at an angle θ into a plurality of laminated divided bodies; polishing both cut surfaces of each laminated divided body; tentatively adhering the laminated divided bodies in such a manner that the polished surfaces face to each other by using a second adhesive; cutting a plurality of tentatively adhered, laminated divided bodies 12 along a second cutting direction (b) vertical to the laminated surface into a plurality of tentatively adhered flat plates 13; polishing both cut surfaces of each tentatively adhered flat plate 13; obtaining long length optical element connected body 14 from the tentatively adhered flat plates 13 by solving the second adhesive; forming the antireflection film on the surface of the connected body 14; and separating the connected body 14 into individual optical elements by cutting the connected body 14 to a predetermined dimension. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an optical element, and more particularly to a method for manufacturing a wavelength separation / polarization separation prism.

  Conventionally, as one of optical elements, as shown in FIG. 3A, a cube-shaped polarization beam splitter in which inclined surfaces of prisms 2 and 3 having a right triangular prism shape are joined and integrated with a polarization separation film 4 interposed therebetween. 1 is known. A wavelength separation film may be formed instead of the polarization separation film 4.

  This type of polarization beam splitter 1 has a function of transmitting a predetermined polarization component of incident light and reflecting other polarization components. Therefore, as shown in FIG. 3B, a predetermined polarization component of the light beam emitted from the light source 5 passes through the polarization separation film 4 and irradiates the disk 6. Since the reflected light from the disk 6 is in a state in which the plane of polarization is rotated, it is reflected by the polarization separation film 4 and detected by the light receiving element 7.

  Patent Document 1 discloses that this type of polarizing beam splitter is manufactured through the following steps.

(A) preparing a plurality of flat optical members, forming a polarization separation film on one surface, and forming a matching film on the other surface;
(B) a step of laminating the optical member in a stepped manner with an adhesive at an inclination angle of 45 ° to form a laminate;
(C) a step of cutting the laminated body bonded and integrated into a plurality of laminated divided bodies at a plurality of parallel cut surfaces having a predetermined pitch along a 45 ° inclination angle;
(D) Mirror-finishing both surfaces of each of the laminated divided bodies, and forming an antireflection film on the processed surface;
(E) a step of laminating a plurality of laminated division bodies formed with an antireflection film in an aligned state, and temporarily fixing each laminated division body with paraffin;
(F) a step of cutting the plurality of temporarily laminated laminated bodies along a cut surface perpendicular to the cut surface to form a temporarily fixed laminate;
(G) Mirror-finishing both surfaces of the cut surface of the temporary fixing laminate, and forming an antireflection film on the processed surface;
(H) a step of cutting the temporary fixing laminated body at a predetermined interval in a direction perpendicular to the cut surface to form a plurality of beam splitter coupled bodies;
(I) A step of heating the beam splitter coupled body to dissolve and remove paraffin to separate the individual beam splitters.

However, according to the manufacturing process, the formation (evaporation) of the antireflection film requires two times on the front and back surfaces in each of the steps (d) and (h), for a total of four times, and the number of deposition processes is large. have. In addition, in the step (h), outgas is generated from paraffin, which is a temporary fixing material, due to heating at the time of vapor deposition, resulting in problems such as “burning” and “spider” in the antireflection film.
JP 2000-143264 A

  Accordingly, an object of the present invention is to provide a method of manufacturing an optical element that can halve the process of forming an antireflection film and that does not cause defects such as “burning” and “spider” in the antireflection film. There is.

In order to achieve the above object, a method for manufacturing an optical element according to the present invention includes:
(A) preparing a parallel plate made of a plurality of transparent media having a light separation film formed on one surface;
(B) a step of forming a laminate by bonding the parallel plates with a first translucent adhesive;
(C) cutting the laminated body into a plurality of laminated division bodies along a plurality of parallel first cutting directions at a predetermined pitch along a predetermined inclination angle;
(D) a step of polishing both surfaces of the cut surface of the laminated divided body;
(E) a step of laminating the polished surfaces of the laminate divided body facing each other, and temporarily bonding with a second adhesive;
(F) cutting a plurality of temporarily bonded laminated division bodies into a plurality of temporarily bonded flat plates along a second cutting direction perpendicular to the laminated surface;
(G) a step of polishing both surfaces of the cut surface of the temporarily bonded flat plate;
(H) dissolving the second adhesive and forming a long optical element assembly from the temporary adhesive flat plate;
(I) forming an antireflection film on the surface of the optical element assembly;
(J) cutting the optical element connector into predetermined optical dimensions and separating them into individual optical elements;
It is provided with.

  In the production method according to the present invention, in the step (I) of forming the antireflection film, the vapor deposition process is reduced by half because the two adjacent surfaces need to be vaporized twice in total. In addition, since the film forming step (I) is performed after the second adhesive that temporarily bonds the flat plate is dissolved, no outgas is generated from the second adhesive due to heating during vapor deposition. Even if paraffin is used as the adhesive of No. 2, there is no problem such as “burning” and “spider” in the antireflection film.

  In the production method according to the present invention, it is preferable to use a photocurable adhesive having substantially the same refractive index as that of the parallel plate as the first adhesive. In the temporary bonding step, a photocurable adhesive may be used as the second adhesive, and the adhesive may be temporarily cured.

  Embodiments of an optical element manufacturing method according to the present invention will be described below with reference to the accompanying drawings.

  The manufacturing method shown below is for manufacturing the beam splitter 1 shown in FIG. 3, and is manufactured in the order of steps (A) to (J) shown in FIGS.

  First, in step (A), a plurality of glass parallel plates 10 are prepared, and a light separation film (polarization separation film, wavelength separation film) is formed on one surface of the parallel plates 10. Examples of the light separation membrane include a PBS membrane and a dichroic membrane.

  In the step (B), the laminated body 11 is formed by bonding the parallel flat plates 10 with a first adhesive in a state of being shifted to a predetermined inclination angle θ (for example, 45 °). In this case, if the jig 20 having the inclined surface 21 with the angle θ is used, the workability is good.

  As a 1st adhesive agent, the material which is insoluble in a solvent and has translucency is preferable, and an ultraviolet curable adhesive agent can be used conveniently. The first adhesive preferably has substantially the same refractive index as the glass material of the parallel plate 10.

  In the step (B), it is not always necessary to bond the parallel plate 10 in a state where the parallel plate 10 is shifted to the predetermined inclination angle θ. However, considering the cutting in the next step (C), it is better to shift the inclination to the inclination angle θ. This is advantageous in that there is no waste of materials.

  Next, in the step (C), the laminated body 11 is divided into a plurality of laminated divided bodies 12 (C ′) along a plurality of parallel first cutting directions (refer to the alternate long and short dash line a) at a predetermined pitch along the inclination angle θ. To see).

  In the step (D), the cut surfaces 12a and 12b of the laminated divided body 12 are 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 step (E), the polished surfaces 12a and 12b of the laminated division body 12 are laminated so as to face each other, and temporarily bonded with a second adhesive. Since the second adhesive is used for temporary adhesion and is removed later, it is not necessary to have translucency, but it needs to have a property of being soluble in a solvent. In the step (E), the laminated divided body 12 is temporarily bonded by temporarily curing a soluble ultraviolet curable adhesive.

  As the solvent for the ultraviolet curable adhesive, for example, a hydrocarbon-based cleaning agent can be preferably used. Further, as the release agent (solvent) for dissolving the temporary adhesive, an aqueous release agent, high-temperature (for example, 80 ° C. or higher) water, an organic solvent, or the like may be used depending on the type of the adhesive.

  Next, in the step (F), the light separating film is formed along the second cutting direction (see the alternate long and short dash line b) perpendicular to the laminated surface of the plurality of laminated division bodies 12 temporarily bonded in the step (E). Cut into a plurality of provisionally bonded flat plates 13 (see F ′) at a predetermined pitch so as not to be included in the cut surface.

  In step (G), the cut surfaces 13a and 13b of the temporary bonding flat plate 13 are polished on both sides. The polishing here is, for example, lapping polishing.

  In the step (H), the temporary adhesive flat plate 13 is immersed in a solvent to dissolve the second adhesive, thereby obtaining a long beam splitter connector 14 (see H ′).

  Next, in step (I), an antireflection film is formed on the surface of the beam splitter assembly 14. Here, an antireflection film is deposited on the adjacent first surface 14a and second surface 14b of the connector 14 in one step, and further, an antireflection film is applied on the adjacent third surface 14c and fourth surface 14d in one step. Evaporate.

  In step (J), the beam splitter coupling body 14 is cut into a predetermined size and separated into individual beam splitters 1.

  The target beam splitter 1 is obtained through the above steps (A) to (J). In this manufacturing method, in the step (I) of forming the antireflection film, the two adjacent surfaces need to be vaporized twice in total, and the vapor deposition step is halved.

  In addition, since the film forming step (I) is performed after the step (H) of dissolving the second adhesive temporarily bonding the temporary bonding flat plate 13, outgas is generated from the second adhesive by heating at the time of vapor deposition. It does not occur. In this embodiment, an ultraviolet curable adhesive is used as the second adhesive, but even if paraffin is used, problems such as “burning” and “spider” do not occur in the antireflection film.

(Other examples)
In addition, the manufacturing method of the optical element which concerns on this invention is not limited to the said Example, It can change variously within the range of the summary.

  For example, as the adhesive, a visible light curable adhesive, a thermosetting adhesive, or the like can be used in addition to the ultraviolet curable adhesive.

It is explanatory drawing which shows the first half process of one Example of the manufacturing method of the optical element which concerns on this invention. It is explanatory drawing which shows the latter half process of one Example of the manufacturing method of the optical element which concerns on this invention. An example of a beam splitter is shown, (A) is a perspective view, (B) is a schematic explanatory drawing which shows a use condition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Polarizing beam splitter 10 ... Parallel plate made of glass 11 ... Laminated body 12 ... Laminated division body 13 ... Temporary adhesion flat plate 14 ... Beam splitter coupling body

Claims (4)

Preparing a parallel plate made of a plurality of transparent media having a light separation film formed on one surface;
Bonding the parallel flat plates with a first translucent adhesive to form a laminate;
Cutting the laminated body into a plurality of laminated divided bodies along a plurality of parallel first cutting directions at a predetermined pitch along a predetermined inclination angle;
Polishing both surfaces of the cut surface of the laminated laminate;
Laminating the polished surfaces of the laminate divided body facing each other, temporarily bonding with a second adhesive,
Cutting the plurality of temporarily divided laminated pieces into a plurality of temporarily bonded flat plates along a second cutting direction perpendicular to the laminated surface;
Polishing both surfaces of the cut surface of the temporary adhesive flat plate;
Dissolving the second adhesive and converting the temporary adhesive flat plate into an elongated optical element assembly; and
Forming an antireflection film on the surface of the optical element assembly;
Cutting the optical element coupling body into predetermined dimensions and separating them into individual optical elements;
An optical element manufacturing method comprising:   2. The method of manufacturing an optical element according to claim 1, wherein a photo-curing adhesive having substantially the same refractive index as that of the parallel plate is used as the first adhesive.   The method for manufacturing an optical element according to claim 1, wherein in the temporary bonding step, a photocurable adhesive is used as the second adhesive, and the adhesive is temporarily cured. 2. The method of manufacturing an optical element according to claim 1, wherein in the step of forming the antireflection film, the antireflection film is formed simultaneously on two adjacent surfaces of the optical element.

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