Paper
1 December 1990 Laser induced narrowing and saturation broadening effects in OPFIRL
Author Affiliations +
Proceedings Volume 1514, 15th International Conference on Infrared and Millimeter Waves; 151460 (1990) https://doi.org/10.1117/12.2301626
Event: 15th International Conference on Infrared and Millimeter Waves, 1990, Orlando, FL, United States
Abstract
The linewidth of optically pumped FIR laser everywhere in the sample tube of OPFIRL was studied theoretically. The NH3 gas was chosen as the operating gas and three-level model was used for the theoretical calculation of the linewidth of FIR laser within the sample tube of the laser system. We found that the sample tube could be divided into three regions: A) The laser induced line narrowing region (L < 10 cm ), where the line centers of Is and Gs characteristic curve were approached with each other, so that the larger Is amplified by larger Gs and vice versa, and the linewidth of FIR laser became narrower and narrower after successive amplification in this region. B) The saturation broadening region ( Lopt < L <10 cm), where Is was large and the Gs at the line center decreased considerably due to the gain saturation effect. In this region, the gain value at the line center was less than its value at off center, so that the spectral line became broader. C) The self-absorption narrowing region ( L < Lopt). In this region the value Ip was less than its threshold value, and the molecules were not activated. The FIR signal was now interacted vith the unactivated molecular system and absorbed by the molecular system. The linewidth of FIR signal would be narrowed due to the absorption saturation effect.
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yikun Lin "Laser induced narrowing and saturation broadening effects in OPFIRL", Proc. SPIE 1514, 15th International Conference on Infrared and Millimeter Waves, 151460 (1 December 1990); https://doi.org/10.1117/12.2301626
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Far infrared lasers

Absorption

Laser systems engineering

Molecules

Optical pumping

Statistical modeling

RELATED CONTENT


Back to Top