System to determine environmental pressure and birefringent-biased cladded optical sensor for use therein
US5589931A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1995 |
| Grant date | Dec 31, 1996 |
| Priority date | — |
| Expiry date | Mar 17, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L11/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A cladded birefringent pressure sensor for use in a pressure-sensing system. The sensor is a single composite plate consisting of two plates each with different indices of refraction. One surface of the sensor is exposed to the environmental pressure under measurement. A collimated broad band light source is transmitted via a fiber optic cable, a polarizer and a birefringent bias element which transmits a wavelength/polarization component of light through the sensor. An external force applied to the sensor adds a stress-induced component to the polarized lightwave. The lightwave exits the sensor and is captured by a second polarizer producing a modulated light spectrum. A focusing element collects the light and transmits it down another fiber optic cable. The cable transmits the light to an opto-electronic interface where the fringe pattern is extracted and a computer compatible signal is generated for a CPU. The CPU performs a Fourier transform on the fringe pattern, where the phase term for a selected frequency is the measure of the externally applied pressure on the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.