Fiber-optic vibration sensor based on frequency modulation of light-excited oscillators
US6246638A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1999 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | Mar 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P2015/0828
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensor device for detecting vibration, including a light source for providing a laser light, a first optical fiber connected to the source for transmitting the laser light, an oscillator positioned to receive the transmitted laser light and adapted to reflect the light as a frequency modulated light; a second optical fiber positioned to capture the frequency modulated light to transmit the frequency modulated light; and a frequency modulated discriminator for receiving the frequency modulated light from the second optical fiber and producing a signal responsive of vibration of the oscillator. In a preferred embodiment, the frequency modulated discriminator further includes a frequency meter for determining the average number of cycles per unit time to provide a second signal responsive of the temperature of the oscillator. The optical fibers may be a pair of different fibers positioned for transmitting the laser light and the frequency modulated light respectively, or the same fiber positioned for transmitting both the laser light and the frequency modulated light. In this latter embodiment, the device further includes a beam splitter to direct the frequency modulated light to th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.