Method for manufacture prism

Abstract

The invention relates to a method for preparing high-accuracy prism, comprising preparing large-scale base plate (1) and small-scale base plate, said large-scale base plate is platform, and the width and thickness of small-scale one is the same to that of large-scale, but the depth is smaller; forming dielectric multiple layer membrane (3) on one side of each base plate, laminating alternatively large-scale and small-scale base plate to form step in width direction according to thickness amount, shoeing out the two end of large-scale base plate in depth direction as base plate surface B; laminated vitreum (4) is cut along direction parallel to step, grinding cut surface of cut multigang vitreum (5); then, cutting multigang vitreum in vertical direction and getting rectangular vitreum (6); cutting it; grinding it taking showed base face B as guideline to form 45 degree grinding surface.

Description

technical field [0001] The invention relates to a method for manufacturing a prism. Background technique [0002] A component of an optical system typified by an optical pickup device includes, for example, a polarizing beam splitter. The polarizing beam splitter is an optical element that separates the laser light emitted from the light source into reflected light and transmitted light. Either one of the reflected light and the transmitted light is directed to the optical disc, and the other is directed to the APC for detecting the intensity of the laser light. (Automatic power control) by light components. Since the reflected light reflected by the polarizing beam splitter is generally reflected at an angle of 90°, the polarized light separation film constituting the polarizing beam splitter is arranged at an angle of 45° to the optical axis. Therefore, a cube-shaped prism was used as the polarization beam splitter, and the polarization separation film was formed on the ...

AI Technical Summary

Problems solved by technology

In addition, since the lamination and cutting of the plate glass and the split laminate are repeated, the cumulative error is further accumulated, and a cutting error also occurs during cutting, so the finally manufactured prism contains a very large error.

In addition, although the plate glass and the laminated divided body are arranged in a step-like shape along the inclined wall, cutting errors may occur during lamination or cutting, and there is also the possibility that errors may occur on the inclined side walls themselves.

[0007] The influence of the above errors may cause a large error in the inclination angle of the film formed inside the finally manufactured prism

Therefore, high-precision angular accuracy cannot be guaranteed, and for this reason, in the invention of Patent Document 1, it is extremely difficult to form a dielectric multilayer film on the prism with high angular accuracy.

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