Method of preventing null point errors in a fibre-optical Sagnac interferometer for revolution rate measurement

摘要

The interferometer has a light source(1), polarizer (3), photodetector (8), a beam divider (4), a fiber optic loop (5), a phase modulator (6) and a processor which produces control and synchronization signals for its synchronous demodulator, digital-to-analogue converter and digital integrator. The method involves decorrelating a disturbance coupled into the detector path of the interferometer, which is proportional to the difference between two successive phase modulator values, from the actual detector signal.