Electric and electromagnetic field sensing system including an optical transducer
US5280173A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1992 |
| Grant date | Jan 18, 1994 |
| Priority date | — |
| Expiry date | Jan 31, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/001
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for sensing electric and electromagnetic fields incorporating a fiber-optic transducer which mounts directly on a conventional optical fiber waveguide. The transducer employs a conductive Fabry-Perot microcavity bounded by a conductive, thin and corrugated diaphragm. When the conductive microcavity is placed in an electric field, the electric field is excluded from within the equipotential microcavity and a net electrostatic force acts on the diaphragm. Likewise, when the conductive microcavity is exposed to an electromagnetic wave, the wave exerts a radiation pressure on the diaphragm. In both cases, the diaphragm deflects linearly and uniformly under the influence of the extremely low electrostatic pressures which are induced. The diaphragm deflection modulates the reflectance within the optical fiber by varying the gap of the cavity. The change in reflected light is measured and correlated to the field strength using an improved dual-wavelength referencing technique which compensates for bending and transmission losses in the optical fiber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.