| 摘要 |
PURPOSE:To decrease the number of parts and to ensure easy adjustment and the like, by using lenses of one axis crystal as an optical coupler in an optical fiber gyroscope. CONSTITUTION:An optical coupler in an optical fiber gyroscope is formed by spherical lenses L3 and L4 made of one axis crystal such as sapphire and a half mirror HF. Propagated light from an optical fiber F1 is reflected by the mirror HF through the lens L3 and becomes counterclockwise light toward an optical fiber coil through the lens L3 and a fiber F3, and also becomes clockwise light toward the lens L4, an optical fiber F4, and the optical fiber coil through the mirror HF. The phase difference between both light beams is adjusted by the rotary angles of the planes of polarization of the fibers F1 and F2 based on respective twistings. The phase difference is made to be pi/2 without using an optical modulator, a polarizing plate, and depolarizer. When an interval F' between the lens and the fiber and an interval L between the lens and the mirror are changed, the coupling efficiency of four optical fibers becomes the maximum value. In this way, the number of parts can be decreased, and the easy adjustment can be ensured. |
