The invention discloses a
fiber-optic
gyroscope which comprises a wide
spectrum light source, an
optical detector, a 2*2 coupler, an integrated optic modulator, a first polarization-maintaining
beam splitter, a second polarization-maintaining
beam splitter and a
fiber loop, wherein the 2*2 coupler is used for splitting light from the wide
spectrum light source, then enabling the split light to enter the integrated optic modulator, and transferring an interfered optical
signal into the
optical detector in split beams; the integrated optic modulator is used for polarizing and splitting beams of a light path,
fast axis branches and slow axis branches of the first polarization-maintaining
beam splitter and the second polarization-maintaining beam splitter are coupled with a
fast axis of a
tail fiber of the integrated optic modulator, the first
branch of the integrated optic modulator is in countershaft
welding with the
fast axis branch of the first polarization-maintaining beam splitter, the second
branch of the integrated optic modulator is in countershaft
welding with the slow axis branch of the second polarization-maintaining beam splitter, the slow axis branch of the first polarization-maintaining beam splitter is in countershaft
welding with the fast axis branch of the second polarization-maintaining beam splitter, and single-ended
tail fibers of the first polarization-maintaining beam splitter and the second polarization-maintaining beam splitter are respectively in countershaft welding with two
tail fibers of the
fiber loop.