PURPOSE: To simplify the constitution of the device, by splitting laser light into two light beams by a polarization beam splitter, propagating the light beams in the right and left directions in a single mode optical fiber loop, making the light beams pass the splitter again, and thereafter imparting phase difference bias thereto.
CONSTITUTION: Light from a laser 1 is split into two polarized light beams, which have vibrating planes that are crossed at a right angle, by a polarization beam splitter 7. The light beams are made to propagate in the right and left directions in a single mode optical fiber loop 3 and made to pass the splitter 7 again. The elliptically polarized light generated by the phase difference which is caused by a Sagnac effect is made to pass a 1/4 wavelength plate 8, and phase difference bias is imparted. Then, said light is converted into the linearly polarized light and further converted into an electric signal by a light detecting piece 9 and a light detector 5. The signal is amplified by an amplifier 6. Thus a conventional polarizing plate can be omitted.
HISAMA KAZUO
ARANISHI TOSHIO
