Tone burst diode laser spectroscopy
US6611335B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 17, 2000 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Aug 17, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/39
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A tone burst spectrometer and spectrometry method comprising employing a narrow bandwidth light source, a tone burst modulation waveform generator, synchronization of a lock-in amplifier to a burst frequency of the generator, and one or more of the following: use of a semiconductor laser; setting the tone frequency of the generator to an integer multiple of the burst frequency; using a tone modulation waveform other than a sine wave; setting the tone frequency of the generator to less than a half width at half maximum of a targeted spectral transition; and producing a spectral feature with a high signal to noise ratio while synchronizing the lock-in amplifier to the tone frequency of the generator or an odd harmonic of the tone frequency and wherein the output of the lock-in amplifier is low pass filtered and negative feedback is employed to stabilize the operating wavelength at or near a center wavelength of a spectral feature of the sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.