Passive sampling interferometric sensor arrays
Coherent distributed sensor and method using short coherence length sources
Distributed sensor and method using coherence multiplexing of fiber-optic interferometric sensors
Distributed sensor array and method using a pulsed signal source
Apparatus and method for minimizing polarization-induced signal fading in an interferometric fiber-optic sensor using input-polarization modulation Patent #: 4932783
ApplicationNo. 706456 filed on 05/28/1991
US Classes:356/478, Multiplexed sensor array250/227.19, With coherent interferrometric light250/227.27With coherent interferrometric light
ExaminersPrimary: Turner, Samuel A.
Assistant: Kurtz, II, Richard E.
Attorney, Agent or Firm
International ClassG01B 009/02
AbstractApparatus and methods for reducing and preventing polarization fading in unbalanced measuring interferometers. An extended interferometer having a plurality of sensors and a compensating interferometer are used. They are driven from a pulsed optical signal source wherein the optical signal comprises sequences of two pulses each. To prevent polarization fading the polarization of a predetermined one of each two-pulse sequence is switched, preferably orthogonally, from sequence to sequence. Interference pulse output groups are produced for each two-pulse driving sequence. Each output group has the same number of usable pulses as the number of sensors in the interferometer.