Frequency modulation spectroscopy using dual frequency modulation and detection
US4765736A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1986 |
| Grant date | Aug 23, 1988 |
| Priority date | — |
| Expiry date | Jul 24, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/4338
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
FM laser spectroscopy apparatus includes a single modulator for modulating a laser beam with first and second modulation signals (.omega..sub.1, .omega..sub.2). The two modulation signals are generated by mixing a signal from a first oscillator (.omega..sub.1 +.omega..sub.2)/2 and a signal from a second oscillator (.omega..sub.1 -.omega..sub.2)/2 and producing the two modulation signals (.omega..sub.1, .omega..sub.2). The modulator produces three groups of sidebands on the laser beam at the laser frequency plus and minus the two modulation frequencies and at plus and minus the difference between the two modulation signal frequencies. The apparatus provides practical high frequency FM spectroscopy as required for the observation of pressure broadened spectral features.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.