Fiber optic gyroscope.

摘要

In a fiber optic gyroscope in which light from a light source (22) is split into two beams for supply to one and the other end of an optical fiber coil (21) respectively, and the two beams having propagated through the optical fiber coil (21) and emitted the one and the other end thereof are coupled together for supply to a photodetector (23), there are separately formed on an optical integrated circuit substrate (30) two optical waveguide couplers (31, 32) , each comprising a trunk (31c, 32c) and a pair of branches (31a, 31b, 32a, 32b) extending therefrom. The pair of branches of a first one of the two optical waveguide couplers (32) are connected to the light source (22) and the photodetector (23), respectively, and the pair of branches of the second optical waveguide coupler (31) are connected to the one and the other end of the optical fiber coil (21), respectively. The trunks of the first and second optical waveguide couplers are interconnected via a connecting optical fiber (35). The optical integrated circuit substrate (30) is fixed to a reinforcing plate of a material which has a thermal expansion coefficient nearly equal to that of the optical integrated circuit substrate. The reinforcing plate is held on a support structure by flexible holding means.