Semiconductor ring laser gyro

1. A semiconductor ring laser gyro comprising:

a semiconductor laser for emitting light from each of both ends thereof;

a splitting means for splitting and guiding the light emitted from the semiconductor laser into two axis directions;

a plurality of reflecting means for reflecting the light split and guided by the splitting means into the two axis directions;

two optical circuits, in each of which the plurality of reflecting means cause the light to travel in a plane and to enter an end of the semiconductor laser opposite to the end from which the light is emitted; and

a blocking means for blocking light traveling in one of the two optical circuits.

2. A semiconductor ring laser gyro according to claim 1 , wherein the one semiconductor laser is disposed at a portion of an optical path shared in common by the two optical circuits which are disposed in respective different planes.

3. A semiconductor ring laser gyro according to claim 1 , wherein the splitting means is a beam splitter which includes a transmissive mirror surface for guiding light into an optical circuit about a first axis and a reflection surface for reflecting light having transmitted through the transmissive surface into an optical circuit about a second axis.

4. A semiconductor ring laser gyro according to claim 1 , wherein the splitting means and the blocking means are comprised by a combination of a polarization beam splitter and a polarization plane rotating element disposed between the polarization beam splitter and the semiconductor laser.

5. A semiconductor ring laser gyro according to claim 4 , wherein the polarization beam splitter is a cube polarization prism which includes two rectangular prisms sandwiching one of a dielectric film and a dielectric multilayer film.

6. A semiconductor ring laser gyro according to claim 4 , wherein the polarization plane rotating element is one of a liquid crystal element and a Faraday element.