In this paper, implementation and experimental test of passive homodyne of fiber interferometer has been done. For this purpose, an all-fiber interferometer was made of two Faraday rotator mirrors, a 3x3 coupler and PZT phase modulator. The quadrature fringe signals trace out an ellipse when the two outputs plotted against each other. By the least-squares fitting method, ellipse unknown parameters accurately have been obtained. The phase changes of interferometer were calculated by the modified unwrapping equation. For real test of the system, some length of interferometer arms are wrapped on a silicon tube and pressure fluctuations inside the tube cause to change phase of interferometer. The phase signal of interferometer ahse been obtained and were compared with the output of electrical pressure sensor.

Keywords: Michelson fiber interferometer, passive demodulation, least-squares fitting

Full-Text [PDF 441 kb]   (885 Downloads)