Atmospheric thermal lensing in laser resonators

Author

Barnes, Norman P. ; Thomas, Milfred E. ; Koch, Grady J. ; Marsh, Waverly D.

Author_Institution

NASA Langley Res. Center, Hampton, VA, USA

Volume

31

Issue

5

fYear

1995

fDate

5/1/1995 12:00:00 AM

Firstpage

962

Lastpage

969

Abstract

Atmospheric absorption degrades laser performance both by absorbing laser energy within the laser resonator, which increases the loss, and by inducing a thermal lens in the atmosphere. Atmospheric thermal lensing can be quite severe, even when the absorption coefficient is quite modest. A model is developed which describes atmospheric thermal lensing; time constants, which are associated with the establishment and decay of the atmospheric thermal lens, are determined; experiments are performed using an injection seeded Ti:Al ₂O₃ laser tuned to the H₂O absorption lines near 0.815 μm to validate the model; dependence of the atmospheric thermal lens on the laser energy and absorption coefficient were measured and found to agree with the model. In addition, the decay of the atmospheric thermal lens with time was measured and also found to agree with the model predictions

Keywords

absorption coefficients; alumina; atmospheric light propagation; laser beams; laser cavity resonators; laser tuning; nonlinear optics; optical radar; solid lasers; thermal blooming; titanium; 0.815 mum; Al₂O₃:Ti; H₂O; H₂O absorption lines; Ti:Al₂O₃ laser; absorbing laser energy; absorption coefficient; atmosphere; atmospheric absorption; atmospheric thermal lensing; injection seeded; laser energy; laser performance; laser resonators; lidars; optical radars; thermal lens; time constants; Absorption; Atmospheric measurements; Atmospheric modeling; Laser modes; Laser tuning; Lenses; Performance loss; Thermal degradation; Thermal lensing; Time measurement;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.375943

Filename

375943