Two-frequency MOPA diode laser system for difference-frequency generation of coherent THz waves
Abstract
We developed a tunable, cavity-locked diode laser source at 850 nm for difference-frequency generation of coherent THz- waves. The difference frequency is synthesized by three fiber-coupled external-cavity diode lasers, where tow of the lasers are locked to adjacent modes of an ultra-stable Fabry-Perot cavity and the third laser is offset-phase- locked to the second cavity-locked laser using a tunable microwave oscillator. The first cavity-locked laser and the offset-locked laser produces the difference frequency, whose value is precisely determined by sum of integer multiple of free spectral range of the Fabry-Perot cavity and the offset frequency. The difference-frequency signal is amplified to 500 mW by the master oscillator power amplifier technique, simultaneous two-frequency injection-seeding with a single semiconductor optical amplifier. Here we demonstrate the difference-frequency generation of THz waves with the low- temperature-grown GaAs photomixers and its application to high-resolution spectroscopy of simple molecules. An absolute frequency calibration was carried out with an accuracy of approximately 10^(-7) using CO lines in the THz region.
Additional Information
© 1999 Society of Photo-optical Instrumentation Engineers (SPIE). The authors thank S. Verghese and K. A. McIntosh of MIT Lincoln Laboratory for preparing the LTG-GaAs photomixers. We also thank T. J. Crawford of Jet Propulsion Laboratory for his technical support. Portions of this work performed at the Jet Propulsion Laboratory California Institute of Technology were done under contract with the National Aeronautics and Space Administration (NASA). G. A. Blake acknowledges additional support from NASA and from the National Science Foundation.Attached Files
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- Eprint ID
- 90733
- Resolver ID
- CaltechAUTHORS:20181107-160518983
- NASA/JPL/Caltech
- NSF
- Created
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2018-11-08Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences
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- Proceedings of SPIE
- Series Volume or Issue Number
- 3617