High-Resolution Terahertz Spectroscopy by a Compact Radiation Source Based on Photomixing with Diode Lasers in a Photoconductive Antenna
✍ Scribed by Shuji Matsuura; Masahiko Tani; Hajime Abe; Kiyomi Sakai; Hiroyuki Ozeki; Shuji Saito
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 104 KB
- Volume
- 187
- Category
- Article
- ISSN
- 0022-2852
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✦ Synopsis
We demonstrate generation of continuous-wave terahertz radiation and its application to molecular spectroscopy. The radiation source is based on the photomixing of two diode laser beams in a low-temperature-grown GaAs photoconductive antenna, which offered output power of several tens of nanowatts at frequencies up to 2 THz with its long term frequency stability being about 5 MHz. The pure rotational spectra of CH 3 CN and isotopomers of CO were measured with this source, and 1% of absorption was clearly detected with a simple amplitude modulation technique. This indicates that the present system has a potential capability for high-resolution and high-sensitivity molecular spectroscopy.