Ultrasonic sensor using short coherence length optical source, and operating method
US5909279A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1997 |
| Grant date | Jun 1, 1999 |
| Priority date | — |
| Expiry date | Mar 17, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01H9/006
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dual time delay interferometer (TDI) enables remote sensing of phase modulated information, such as the detection of ultrasonic vibrations from highly diffuse surfaces, preferably in the range from about 10 kHz to 100 MHZ or more. The system can also be configured in a transceive mode with a dual pass through a single TDI, which is well suited to optical communications. A non-steady-state photo-electromotive-force detector tracks the movement of interference fringes (whose position shifts as the surface vibrates), rather than their absolute position. A phased array of the sensors can be used for enhanced imaging applications requiring better signal/noise ratios, or alternatively, when lower power optical sources are employed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.