1. Gain enhancement in a terahertz quantum cascade laser with parylene antireflection coatings.
- Author
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Rungsawang, R., Jukam, N., Maysonnave, J., Cavalié, P., Madéo, J., Oustinov, D., Dhillon, S. S., Tignon, J., Gellie, P., Sirtori, C., Barbieri, S., Beere, H. E., and Ritchie, D. A.
- Subjects
TERAHERTZ technology ,QUANTUM theory ,LASERS in physics ,ELECTRONIC amplifiers ,ELECTRONICS ,OPTICAL coatings - Abstract
We study the effect of parylene antireflection coatings on the gain of a 2.8 THz quantum cascade laser using terahertz time-domain spectroscopy. With antireflection coatings the threshold current increases as the mirror losses are increased, and the gain clamps at 16 cm
-1 , compared to 10 cm-1 for an uncoated device. These values are consistent with a drop in reflectivity from 0.320 to 0.053 as a consequence of the coating deposition. Further improvements could reveal the bare cavity gain and permit the quantum cascade laser to be used as an efficient terahertz amplifier. [ABSTRACT FROM AUTHOR]- Published
- 2011
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