A new mechanism was found to alleviate the thermally induced phase mismatch of nonlinear optical crystals. By cooling CsLiB><sub>6</sub>O<sub>10</sub> at an elevated crystal temperature with gas, we improved laser conversion efficiency from green (532 nm) to UV (266 nm) 2.3 times compared with that without cooling. <i>In situ</i> observation of the temperature profile on the output surface revealed that such cooling initiates a negative temperature profile that compensates for the positive profile generated from laser absorption. A 10.6-W UV output with excellent stability was generated. The optimum crystal length was substantially extended.
© 1998 Optical Society of America
(140.3580) Lasers and laser optics : Lasers, solid-state
(140.3610) Lasers and laser optics : Lasers, ultraviolet
(160.4330) Materials : Nonlinear optical materials
(190.0190) Nonlinear optics : Nonlinear optics
(190.2620) Nonlinear optics : Harmonic generation and mixing
Y. K. Yap, K. Deki, N. Kitatochi, Y. Mori, and T. Sasaki, "Alleviation of thermally induced phase mismatch in CsLiB6O10 crystal by means of temperature-profile compensation," Opt. Lett. 23, 1016-1018 (1998)