High-sensitivity infrared heterodyne radiometer using a tunable-diode-laser local oscillator
Abstract
A blackbody heterodyne radiometer using a widely tunable PbSnSe-diode laser as the local oscillator (LO) achieved signal-to-noise performance that was an order of magnitude better than previously reported and only a factor of 2.5 below that obtained with a CO2-laser LO. The diode-laser system performance was within a factor of six of an ideal radiometer. High-resolution blackbody heterodyne absorption spectra of ethylene at 10.6 microns were obtained with a 0.4-sec postdetection integration time by tuning the diode LO in a closed-cycle cryogenic cooler.
- Publication:
-
Optics Letters
- Pub Date:
- September 1977
- DOI:
- 10.1364/OL.1.000084
- Bibcode:
- 1977OptL....1...84K
- Keywords:
-
- Heterodyning;
- Infrared Radiometers;
- Molecular Spectroscopy;
- Semiconductor Lasers;
- Absorption Spectra;
- Ethylene;
- Line Spectra;
- Oscillators;
- Photodiodes;
- Signal To Noise Ratios;
- Spectral Resolution;
- Tuning;
- Instrumentation and Photography;
- LASERS: DIODE;
- REMOTE SENSING;
- HETERODYNING;
- RADIOMETERS;
- SPECTROSCOPY: INFRARED