Japan Aviation Electronics Industry, Limited

Eiichi Asami

Osamu Hashiguchi

Akira Watanabe

Hideo Sugimoto

Keiichi Mori

Shuichi Aihara

Yoshihiko Hamada

Satoshi Kai

Takayoshi Yamauchi

Ryoji Kaku

Masuo Nishimoto

Hiroyuki Takahashi

Aritaka Ohno

Kazuhiro Sakuma

An optical module is formed of a first optical block and a second optical block each equipped with a lens the optical axis of which needs to be aligned, the blocks being positioned and secured to each other, and has stepwise positioning means. A positioning means includes spring pieces each having an abutting slope, and edges. Four spring pieces are formed in the second optical block such that their abutting slopes are disposed at four corners of the second optical block. Positioning is implemented when the abutting slopes meet the edges of the first optical block. Another positioning means includes a depressed part and a guide slope formed in one of the two optical blocks and a raised part formed in the other optical block. The raised part is fitted into the depressed part.

Optical module

Optical interferometric gyro having reduced return light to the light

In a waveguide type optical device which has an optical waveguide and modulation electrodes for varying its refractive index, both formed in the top of a substrate and a ferroelectric crystal having a pyroelectric effect, the top of the crystal substrate being parallel to the direction of its spontaneous polarization, conductive films are formed in two surfaces of the crystal substrate which cross the direction of the spontaneous polarization. The conductive films are electrically interconnected to thereby prevent a change in the operating temperature characteristic of the optical device which is caused by the pyroelectric effect of the crystal substrate.

Waveguide type optical device

In a fiber optic gyroscope in which light from a light source is split into two beams for supply to one and the other end of an optical fiber coil respectively, and the two beams having propagated through the optical fiber coil and emitted the one and the other end thereof are coupled together for supply to a photodetector, there are separately formed on an optical integrated circuit substrate two optical waveguide couplers, each comprising a trunk and a pair of branches extending therefrom. The pair of branches of a first one of the two optical waveguide couplers are connected to the light source and the photodetector, respectively, and the pair of branches of the second optical waveguide coupler are connected to the one and the other end of the optical fiber coil, respectively. The trunks of the first and second optical waveguide couplers are interconnected via a connecting optical fiber. The optical integrated circuit substrate 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.

Fiber optic gyroscope using optical waveguide couplers

Growing community of inventors

Tokyo, Japan

Eiichi Asami