Farhoomand, Jam and Blake, Geoffrey A. and Frerking, M. A. and Pickett, Herbert M. (1985) Generation of tunable laser sidebands in the far-infrared region. Journal of Applied Physics, 57 (5). pp. 1763-1766. ISSN 0021-8979 http://resolver.caltech.edu/CaltechAUTHORS:20120628-072530380
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Continuously tunable laser sidebands have been generated by mixing radiation from an optically pumped far infrared (FIR) molecular laser, operated at 693, 762, 1627, and 1839 GHz, with that from millimeter‐wave klystrons in a Schottky‐barrier diode. An enhancement in conversion efficiency over similar systems reported previously is obtained by using a Michelson interferometer to separate the sidebands from the carrier and by placing the Schottky diode in an open structure corner cube mount. With 4 mW of laser power at 693 and 762 GHz the sideband power was measured to be 3.0 μW. This is at least an order of magnitude better than the previously reported results. At higher frequencies, 22 mW of 1627‐GHz laser power produced about 2.5 μW of sideband output, while 3mW of 1839‐GHz laser power generated about 100 nW of sideband radiation. The lower efficiency at the higher frequencies is due primarily to the mismatch between the laser radiation and the fixed‐length diode antenna. To demonstrate the tunability of the generated far‐infrared radiation, the laser sidebands were swept through absorption lines of HDO and H_2CO near 600 and 800 GHz. The absorption signals were easily seen, using either video or lock‐in detection techniques.
|Additional Information:||© 1985 American Institute of Physics. Received 9 July 1984; accepted 22 October 1984. We would like to acknowledge Ed Cohen for his help with the rotational line measurements and Mark Schaefer for his work on the comer cube mixer used in these experiments. We would also like to thank Timothy Boyd for his early work on many of the components. The research described in this paper was performed by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.|
|Subject Keywords:||TUNING, FAR INFRARED RADIATION, OPTICAL PUMPING, MICROWAVE RADIATION, KLYSTRONS, SCHOTTKY BARRIER DIODES, CARBON DIOXIDE LASERS, LASERS, GHZ RANGE 100−1000, HEAVY WATER, FORMALDEHYDE, EFFICIENCY, EXPERIMENTAL DATA, POWER, HARMONICS, COUPLING, MICHELSON INTERFEROMETER, MIXING|
|Classification Code:||PACS: 42.55.-f, 42.60.By, 42.65.Dr, 42.65.Es, 42.65.Ky|
|Official Citation:||Generation of tunable laser sidebands in the far‐infrared region Jam Farhoomand, Geoffrey A. Blake, M. A. Frerking, and Herbert M. Pickett J. Appl. Phys. 57, 1763 (1985); http://dx.doi.org/10.1063/1.334454|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||28 Jun 2012 14:48|
|Last Modified:||26 Dec 2012 15:25|
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