Title :
Thermal beam distortions in end-pumped Nd:YAG, Nd:GSGG, and Nd:YLF rods
Author :
Pfistner, C. ; Weber, R. ; Weber, H.P. ; Merazzi, S. ; Gruber, R.
Author_Institution :
Inst. of Applied Phys., Univ. of Berne, Switzerland
fDate :
7/1/1994 12:00:00 AM
Abstract :
The thermally induced beam distortions in end-pumped Nd:YAG, Nd:GSGG, and Nd:YLF rods were analyzed and the influence of edge- and face-cooling was investigated. The distributions of temperature, stress, and strain in the crystals were calculated by finite element analysis. Based on these data, the space-resolved changes of the refractive index were determined considering thermal dispersion, surface deformation, and strain-induced birefringence. The resulting optical path difference for one round-trip in the end-pumped rods was integrated numerically. For each rod, the induced thermal lens was determined over the extent of the pump spot radius. The calculations of the optical path difference were experimentally confirmed by investigations using a modified Twyman-Green interferometer with a polarized HeNe probe beam at 633 nm under lasing and nonlasing conditions
Keywords :
finite element analysis; laser beams; laser theory; mechanical birefringence; neodymium; optical dispersion; optical pumping; refractive index; solid lasers; thermo-optical effects; 633 nm; GdScGG:Nd; GdScGa5O12:Nd; LiYF4:Nd; Nd:GSGG; Nd:YAG; Nd:YLF; Twyman-Green interferometer; YAG:Nd; YAl5O12:Nd; YLF:Nd; crystals; edge-cooling; end-pumped rods; face-cooling; finite element analysis; numerical integration; optical path difference; polarized HeNe probe beam; refractive index; strain distribution; strain-induced birefringence; stress distribution; surface deformation; temperature distribution; thermal beam distortions; thermal dispersion; thermal lens; Capacitive sensors; Crystals; Finite element methods; Optical distortion; Optical interferometry; Optical pumping; Optical refraction; Optical variables control; Temperature distribution; Thermal stresses;
Journal_Title :
Quantum Electronics, IEEE Journal of
