JPH1123845A - Laminated polarizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated polarizer easy to handle and hardly being damaged by arranging a high polymer film on one side of a multilayer film. SOLUTION: This polarizer is constituted so that the high polymer film 4 is arranged on one side of the multilayer film 3 alternately laminated with plural dielectric films 1 and plural metallic films or semiconductor films 2. As the dielectric film 1 in such a case, a silicon dioxide, etc., is used. As the metallic film, e.g. an aluminum film, a gold film, etc., are used. As the semiconductor film, a germanium film, a silicon film, etc., are used. Further, as the high polymer film 4, various high polymer films are used, and e.g. a polymethyl methacrylate film, a polycarbonate film, a polystyrene film, a polyimide film, etc., are used. Further, the high polymer film 4 doesn't mean only a high polymer material single body, but may be the substance forming the metallic film, etc., on the high polymer film 4 also. Further, the thickness of the high polymer film 4 is defined so that the whole laminated polarizer has flexibility.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel laminated polarizer.

[0002]

2. Description of the Related Art A polarizer is a basic optical passive element and an indispensable element in configuring many optical devices. Many types of polarizers have been developed, for example, birefringent prism polarizers such as Glan-Thompson and Glan-Taylor, wire grid polarizers, dichroic polarizing films, birefringent diffraction gratings, polarizing glass, laminated polarizers Etc. Many of these have an element length of mm unit, but the laminated polarizer is several tens μm.
Is manufactured.

[0003] With the recent development of optical communication systems, various optical components have been developed, and various requirements have also been imposed on polarizers used therein. For example, an optical component in which a thin polarizer is inserted into an optical element having a minute gap formed in the optical path is used. The polarizer is required to be very thin in order to reduce excess loss generated when the polarizer is inserted. For example, by setting the minute gap in the optical path to several tens of μm or less (the thickness of the polarizer is less than that), excess loss is reduced to 0.1 μm.
It can be suppressed to about 5 dB. Only a laminated polarizer can realize this thinness. This laminated polarizer is disclosed by Kawakami et al. In JP-A-55-117108.

[0004] Laminated polarizers having improved characteristics are disclosed in JP-A-4-256904 and JP-A-6-265834. The basic structure of this laminated polarizer is a multilayer film in which a dielectric such as silicon dioxide having a thickness of about 1 μm and a metal or semiconductor thin film having a thickness of about 5 to 10 nm are alternately laminated on a substrate such as glass. It is formed. When actually manufacturing a laminated polarizer, a multilayer film with a substrate is cut into a thin plate shape using a dicing saw or the like.
Polished to a thickness of μm. However, handling in this step is very difficult, breakage easily occurs, and the yield is poor. In addition, when this laminated polarizer is mounted on an optical element, it has to be inserted into a minute gap of several tens of μm or less as described above, and there is a problem that the laminated polarizer may be damaged depending on the insertion method. Occur. This is because the conventional laminated polarizer has a configuration in which the glass substrate and the multilayer film are integrated, and both the substrate and the multilayer film are very fragile. Therefore, there has been a demand for a method of manufacturing a laminated polarizer having a good yield and a laminated polarizer that can be inserted into a minute gap in an optical path without being damaged.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laminated polarizer which is easy to handle and is less likely to be damaged.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, have found that the problem can be solved by adopting a new structure of the laminated polarizer. Was completed.

That is, in the laminated polarizer of the first invention of the present invention, a polymer film is disposed on one side of a multilayer film in which a plurality of dielectric films and a plurality of metal films or semiconductor films are alternately laminated. It is characterized by having a configuration.

A laminated polarizer according to a second aspect of the present invention has a structure in which a polymer film is disposed on both sides of a multilayer film in which a plurality of dielectric films and a plurality of metal films or semiconductor films are alternately laminated. It is characterized by doing.

In the laminated polarizer according to the third aspect of the present invention, a polymer film is disposed on one or both sides of a multilayer film in which a plurality of dielectric films and a plurality of metal films or semiconductor films are alternately laminated. In the laminated polarizer having the above structure, the thickness of the polymer film is five times or more the thickness of the multilayer film.

Hereinafter, the present invention will be outlined.

FIG. 1 shows a configuration example of a laminated polarizer according to the present invention in which one side of a multilayer film is a polymer film. FIG. 2 shows a configuration example of a laminated polarizer according to the present invention in which a polymer film is formed on both sides of the multilayer film. In the figure, reference numeral 1 indicates a dielectric film, reference numeral 2 indicates a metal film or a semiconductor film, and reference numeral 3
Denotes a multilayer film, and reference numeral 4 denotes a polymer film.

As the dielectric film, a silicon dioxide film or the like can be used. As the metal film, for example, an aluminum film, a gold film, or the like can be used. As a semiconductor film, a germanium film,
A silicon film or the like can be used. The respective thicknesses vary depending on the performance of the laminated polarizer to be manufactured, but the dielectric film is about 1 μm, and the metal or semiconductor film is 5 to
Used at 10 nm. Various polymer films can be used as the polymer film, and for example, a polymethyl methacrylate film, a polycarbonate film, a polystyrene film, a polyimide film, and the like can be used. The polymer film does not mean only the polymer material alone, but may be a polymer film formed by forming a metal film or the like if necessary. The thickness of the polymer film only needs to be flexible throughout the laminated polarizer. Ideally, the thickness is preferably five times or more the thickness of the multilayer film.

As a method of manufacturing the laminated polarizer of the present invention, for example, a dielectric film and a metal film or a semiconductor film are alternately laminated on a temporary substrate such as quartz glass or silicon and then peeled off from the temporary substrate to form a polymer film. May be attached to one or both sides, or a dielectric film and a metal film or a semiconductor film may be alternately laminated on a substrate made of a polymer material.

[0014]

Example 1 A 0.6 mm thick polyimide molded product (film)
A 0.1 μm-thick aluminum vapor-deposited film 6 was formed on 5 and optically polished to obtain a substrate for producing a laminated polarizer. On this substrate, a 1 μm thick quartz was used as a target by high frequency sputtering in an atmosphere of argon and oxygen.
m of the quartz film 7 was formed. Subsequently, a germanium film 8 having a thickness of 8 nm was formed in a argon atmosphere using germanium as a target by high frequency sputtering. This quartz film and germanium film forming process were performed 100 times each to form a multilayer film having a cross-sectional structure shown in FIG. In the figure, reference numeral 9 denotes a repetition of a quartz film and a germanium film.

Next, this multilayer film was cut out at intervals of 20 μm using a dicing saw. In addition, a strip-shaped multilayer
Cutting was performed every mm. Thus, a laminated polarizer having a width of 2 mm, a height of about 0.7 mm, and a thickness of 20 μm was obtained. There was no damage at the time of cutting. Also, no damage was caused even when inserted into an optical waveguide having a 30 μm groove. The extinction ratio of this laminated polarizer had a value exceeding 40 dB at a wavelength of 1.3 μm, and had sufficient performance as a polarizer. The thickness of the polymer film is about six times the thickness of the multilayer film.

[0016]

Example 2 A multilayer film was formed on a 0.6 mm-thick polyimide substrate in the same manner as in Example 1, and a polyimide precursor solution was applied on the multilayer film by spin coating. Then, a polyimide film having a thickness of 50 μm was formed by heating and curing. Cut out with a dicing saw in the same manner as in Example 1, width 2 mm, height about 0.75 mm,
A 20 μm-thick laminated polarizer was obtained. There was no damage at the time of cutting. Also, no damage was caused even when inserted into an optical waveguide having a 30 μm groove. In addition, since both surfaces were covered with the polymer film, it was very strong against impact on the surface of the laminated polarizer. The extinction ratio of this laminated polarizer had a value exceeding 40 dB at a wavelength of 1.3 μm, and had sufficient performance as a polarizer. The thickness of the polymer film is about seven times the thickness of the multilayer film.

[0017]

COMPARATIVE EXAMPLE 1 A conventional laminated polarizer having a thickness of 20 μm formed on a glass substrate is partially damaged when cut out with a dicing saw, and when inserted into an optical waveguide having a 30 μm groove formed therein, depending on the manner of insertion. In some cases, it was damaged.

[0018]

COMPARATIVE EXAMPLE 2 In a laminated polarizer having a polymer film having a thickness of four times the thickness of the multilayer film, 20 were broken when an insertion test of 100 was inserted into the optical waveguide.

[0019]

As described above, the laminated polarizer of the present invention has the advantages that it can be manufactured with a high yield and that it is hardly damaged during use. By utilizing these characteristics, there is an advantage that an optical component such as an optical waveguide can be easily and inexpensively manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a laminated polarizer according to the present invention in which one surface is a polymer film.

FIG. 2 is a diagram showing a configuration example of a laminated polarizer according to the present invention, in which both surfaces are polymer films.

FIG. 3 is a cross-sectional view of the laminated polarizer of Example 1.

[Explanation of symbols]

 Reference Signs List 1 dielectric film 2 metal film or semiconductor film 3 multilayer film 4 polymer film 5 polyimide film 6 aluminum film 7 quartz film 8 germanium film 9 represents repetition of quartz film and germanium film

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Kuki Takenaka 1-3-1 Gotenyama, Musashino-shi, Tokyo NTT Advanced Technology Co., Ltd.

Claims (3)

[Claims] 1. A laminated polarizer comprising a multilayer film in which a plurality of dielectric films and a plurality of metal films or semiconductor films are alternately laminated, wherein a polymer film is disposed on one side of the multilayer film. A laminated polarizer, characterized in that: 2. A laminated polarizer comprising a multilayer film in which a plurality of dielectric films and a plurality of metal films or semiconductor films are alternately laminated, wherein a polymer film is disposed on both sides of the multilayer film. A laminated polarizer, characterized in that: 3. The laminated polarizer according to claim 1, wherein the thickness of the polymer film is at least five times the thickness of the multilayer film.