Phase modulator, phase modulator assembly, and photosensor

摘要

The present invention provides a photosensor that uses a phase modulation technique for optical detection and conducts a highly accurate measurement. The photosensor uses a phase change difference of light propagated through a polarization preserving fiber with respect to tensile stress and employs proper polarization preserving fibers for a phase modulator 10, light-transmitting polarization preserving fiber 23, and coil-shaped polarization preserving fiber 30, to achieve a highly accurate measurement.