Enhanced detection of acousto-photonic emissions in optically turbid media using a photo-refractive crystal-based detection system
US7652773B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 20, 2005 |
| Grant date | Jan 26, 2010 |
| Priority date | — |
| Expiry date | Jun 19, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0427
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method of detecting acousto-photonic emissions in optically turbid media that provide increased levels of detection sensitivity. The detection system includes an ultrasonic transducer, a laser, a photo-detector for detecting ultrasound-modulated laser light, and circuitry for processing the detected signals for subsequent analysis. The ultrasonic transducer generates an ultrasonic wave that propagates within an optically turbid medium. The laser generates a coherent light beam, which is split to form signal and reference beams. The signal beam is sent through the turbid medium, where it is phase modulated by the ultrasound. The ultrasound-modulated signal beam is provided to a photo-refractive crystal for subsequent interference with the reference beam to convert the phase modulation to intensity modulation. The DC offset of the signal beam intensity provides a measure of the magnitude of the mean phase shift induced by the ultrasound on the multiply scattered optical field within the turbid medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.