Method and apparatus for detecting optical spectral properties using optical probe beams with multiple sidebands
US7379652B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2006 |
| Grant date | May 27, 2008 |
| Priority date | — |
| Expiry date | May 11, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/4338
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Techniques for detecting optical spectral properties of a target are described. The technique includes providing an optical carrier which has an optical frequency bandwidth which is narrow compared to the width of the narrowest spectral feature of the target to be determined. This optical carrier is then electro-optically modulated with an RF frequency chirp, creating an optical chirp probe beam with a frequency chirped optical spectrum having upper and lower frequency chirped sidebands that have amplitudes sufficient to be detected at a detector. The sidebands are frequency bands arranged symmetrically around the optical carrier frequency. The attributes of a sideband include a start frequency, bandwidth and chirp rate. A probe beam is generated with the sidebands and directed onto a target having a physical property with optical frequency dependence. An optical response signal resulting from an interaction between the probe beam and the target is detected. The optical frequency dependence of the physical property of the target is determined based on the optical response signal and the attributes of the sidebands.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.