System and Method for Minimizing Input Polarization-Induced Phase Noise in an Interferometric Fiber-Optic Sensor Depolarized Input Light.
Patent, Filed 18 Sep 90, patented 14 Apr 92,
DEPARTMENT OF THE NAVY WASHINGTON DC
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A system and method for minimizing polarization-induced phase noise in an interferometric fiber sensor is disclosed. The system includes an optical source of light a single mode input fiber means coupled between the optical source and the input fiber for scrambling the polarization state of the light from the optical source at a first frequency to effectively produce and pass depolarized light to the input fiber an interferometric fiber sensor responsive to light from the input fiber for producing at its output an interference pattern proportional to a phase shift produced by a field being sensed by the interferometric fiber sensor detection means responsive to the interference pattern for developing a photocurrent signal averaged over a period of time longer than the period of the first frequency and demodulation means responsive to the photocurrent signal for producing an electrical output signal substantially proportional to the phase shift produced by the field being sensed by the interferometric sensor.
- Miscellaneous Detection and Detectors
- Fiber Optics and Integrated Optics