Cavity enhanced absorption spectroscopy with a laser modulation side-band frequency locked to the cavity
US9200960B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 2013 |
| Grant date | Dec 1, 2015 |
| Priority date | — |
| Expiry date | Feb 8, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/0237
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A cavity enhanced absorption spectrometer (CEAS) and method for controlling the same. The CEAS includes a coherent electro-magnetic radiation source, an electro-magnetic modulator that creates a sideband with an adjustable frequency that is offset from the radiation source frequency by imparting an adjustable frequency modulation to the radiation. The CEAS also includes a RF source that drives the electro-magnetic modulator and a cavity enhanced absorption resonator (CEAR) that receives the sideband. A detector measures the proximity of the frequency of the sideband relative to the resonant frequency of the CEAR and generates a proximity detector signal, which is converted by a controller to a control signal that controls at least one of the RF source and the resonant frequency of the CEAR such that the frequency of the sideband and the resonant frequency of the CEAR are adjusted to maintain a predetermined proximity therebetween.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.