JPS6190101A - polarization separator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to the deflection formation perpendicular to the plane of incidence of parallel incident light rays (S
This invention relates to an improvement in a polarization separator that reflects components (P waves) parallel to the plane of incidence and transmits components parallel to the incident plane (P waves) without reflection.

The polarization separator is made of a glass substrate with a polarization separation film on one side and a total reflection film on the other side, and this substrate is sandwiched and bonded between two prisms.

At this time, since the film formed on the glass substrate controls the characteristics of the completed deflection separator, it must be stable and perfect both during and after the manufacturing process.

[Conventional technology]

A side view of an example of a conventional polarization 'j+ separator is shown in FIG.

1 is a glass substrate, on one side of which is provided a deflection separation film 2 formed by coating alternately laminated films of two dielectrics with different refractive indexes, Sin and Tie. Further, on the other side, a total reflection g3 made of a similar M and a body is provided. This glass substrate 1 has two prisms 4 and 5.
It is sandwiched between the two prisms and integrated with two prisms using adhesive.

The effect of polarization separation of incident light is as follows.

The vertically polarized component (So) of the parallel incident light from the left is reflected by the polarization separation film 2, passes through the total reflection film 3, and is almost entirely reflected upward. On the other hand, the parallel component (PO) passes through the deflection separation membrane 2 and leaks to the right in the separation direction to some extent.

The degree of separation of S waves and P waves is related to the wavelength, and as the wavelength of the incident light becomes longer, the thickness of the total reflection film must be increased in order to obtain a good steepness.

In order to obtain a separation degree of 3QdB or more per length e of a corner of 1μ or more, a film thickness of 6μ or more is required.

[Problems with attempting to defraud inventions]

As mentioned above, since the total reflection film used for long wavelengths has a large film thickness, it suffers from distortion during manufacturing and eventually cracks, resulting in peeling of the film.

In order to avoid this problem, a method of reducing the film thickness by using a metal film such as Cu instead of a dielectric film is used, but the surface of the formed total reflection film is weak and may peel off when adhering to the prism. The problem is that it can cause problems and is unreliable.

[Means for solving problems]

The above problem can also be solved by using two glass substrates each having a deflection separation film made of mutually laminated dielectric multilayer films on one side and a total reflection film made of a metal film covered with a dielectric protective film on the other side. This problem is solved by the polarization separator according to the present invention, which is glued between prisms. Since it is made of a thin metal film, no distortion occurs and no peeling occurs. In addition, since the metal film with a weak surface has a maintenance layer, it is stable even when it is bonded to a prism using an adhesive, and the phenomenon of peeling due to reaction with the adhesive is prevented.〇 [Example] This invention The gist of this will be explained in detail with reference to the embodiment shown in FIG.

The figure shows a side view of the polarization spectrometer. In the figure, the same parts as the conventional example are denoted by the same number and the same symbol. ℃ covered and protected by 8i0t6.

The metal film and protective film are provided on the glass substrate using vapor deposition and sputtering methods.

As the polarization separation film 2, a dielectric laminated film similar to the conventional one is used.

〔Effect of the invention〕

As explained above, in the polarization separator according to the present invention, the total reflection film is made relatively thin and the strength of the surface is protected, so that a total reflection surface that is safe and fully functional during manufacturing and after completion can be obtained. The effect is remarkable.

[Brief explanation of the drawing]

The figures are side views of a deflection separator, with FIG. 1 showing an embodiment of the present invention and FIG. 2 showing a known example. In the figure, 1 indicates a glass substrate 2, a polarized light separation film 3, a total reflection film 4.5, a prism 6, a dielectric laminated film Po according to the present invention, P indicates horizontally polarized light So, and S indicates vertically polarized light. Ka 1 Inra 2 A

Claims (1)

[Claims] A glass substrate, which has a polarization separation film made of alternating dielectric multilayer films on one side and a total reflection film made of a metal film covered with a dielectric protection film on the other side, is placed between two prisms. A polarized light separator characterized by being adhesively clamped.