US 7,564,563 B2
Laser gyro and electronic device using the same
Noriyuki Yokouchi, Tokyo (Japan); Junji Yoshida, Kyoto (Japan); Takahisa Harayama, Kyoto (Japan); Takehiro Fukushima, Kyoto (Japan); Akihiko Kasukawa, Tokyo (Japan); Shuichi Tamura, Kyoto (Japan); Keizou Inagaki, Kyoto (Japan); and Morito Matsuoka, Kyoto (Japan)
Assigned to Advanced Telecommunications Research Institute International, Kyoto (Japan); and The Furukawa Electric Co., Ltd., Tokyo (Japan)
Filed on May 31, 2007, as Appl. No. 11/806,486.
Claims priority of application No. 2006-154906 (JP), filed on Jun. 02, 2006; and application No. 2006-172647 (JP), filed on Jun. 22, 2006.
Prior Publication US 2007/0291273 A1, Dec. 20, 2007
Int. Cl. G01C 19/72 (2006.01)
U.S. Cl. 356—461 5 Claims
OG exemplary drawing
 
1. A laser gyro comprising:
a Si substrate;
laser light excitation means formed on the Si substrate and configured to excite first and second laser lights propagating in clockwise and counterclockwise directions in a circular ring-shaped path;
coupling means formed on the Si substrate, said coupling means formed of a SiO2 multilayer film optical waveguide and configured to superimpose the first and the second laser lights; and
a photodetector disposed on the Si substrate and configured to observe an interference signal generated by the superimposed first and second laser lights, wherein
the laser light excitation means includes a circular ring-shaped optical waveguide formed of a SiO2 multilayer film and a semiconductor optical amplifier coupled to the circular ring-shaped optical waveguide so that the semiconductor optical amplifier and the circular ring-shaped optical waveguide form the circular ring-shaped path,
the coupling means includes an optical coupler configured to extract the first and the second laser lights from the ring-shaped path, and
the semiconductor optical amplifier and the photodetector are disposed individually in concave portions, each concave portion being formed by removing the multilayer film partly.