Two step discrete phase shift demodulation method for fiber optic sensor arrays
US6154308A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 30, 1998 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Jul 30, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/35303
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Optical signals input to a sensor array that includes a plurality of pathlength mismatched interferometers are phase modulated. Two different phase steps are generated in sequence within a time interval T in signals output from the interferometer array. Signals output from the array are processed to produce a first output signal S.sub.1 that is a function of the phase shift .phi. and a first one of the phase steps in a first portion of the time interval T and a second output signal S.sub.2 that is a function of the phase shift .phi. and the other one of the phase steps in a second portion of the time interval T. The signals S.sub.1 and S.sub.2, are processed to calculate the phase shift .phi. in optical signals that have propagated through the sensor array as functions of the sum and differences of the signals S.sub.1 and S.sub.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.