Optical fiber Sagnac interferometer using a polarizing beam splitter

摘要

The present invention relates to an improved Sagnac interferometer. The Sagnac interferometer includes: a light source; A sensing unit that divides the light input from the light source into a vertically polarized first beam and a second beam, moves the first beam and the second beam along opposite directions in a closed path, and outputs the combined light again; And a demodulator for interfering with the first beam and the second beam output from the detector and measuring a phase change induced therebetween. The sensing unit may include a polarizing beam splitter that divides the light input from the light source into vertically polarized first and second beams, and outputs the divided beams to different output ports. The first beam and the second beam output from the polarization beam splitter are switched in directions opposite to each other so that the first beam is input to the output port of the second beam and the second beam is input to the output of the first beam The first beam and the second beam outputted from the polarization maintaining optical fiber coil are polarized perpendicularly to each other and combined in a polarization beam splitter to be outputted on the same path to be provided to the demodulator . The Sagnac interferometer detects and provides a rotational angular velocity using a phase difference between the first beam and the second beam.