Optical branching and coupling circuit

Abstract

Abstract PURPOSE:To obtain a branching and coupling circuit of high accuracy by providing lenses which make the light out from optical fibers into nearly parallel rays and plural polarizing and separating elements which receive the parallel rays from these lenses. CONSTITUTION:An optical branching and coupling circuit is provided with optical fibers 111, 112-11n+1, lenses 211, 212-21n+1, polarizing and separating elements 311, 322-31n, phase difference plates 411, 412, etc. When linearly polarized light is made incident to 1/2 wavelength plates 411, 412, the exit light is converted to the linearly polarized light rotated by 2theta with respect to the linearly polarized light which is the incident light. (The theta is the angle assumed by the 1/2 wavelength plate and the crystal optical axis). The light out from the fiber 11 is made into nearly parallel beams by the lens 211 and is then coupled and propagated to the fibers 113, 11n, 11n+1, etc. According to this invention, the branching and coupling circuit of high accuracy is obtained with the simple constitution wherein the plural polarizing and separating elements and the phase difference plates are combined.

Inventors

• 👤 Teruhito Matsui
• 👤 松井　輝仁

Bibliographic Details