Open AccessRealizing a high-efficiency 426nm laser with PPKTP by reducing mode-mismatch caused by the thermal effect
Author(s) -
Qingwei Wang,
Tian Liang,
Wenxiu Yao,
Yajun Wang,
Yaohui Zheng
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.028534
Subject(s) - optics , materials science , energy conversion efficiency , laser , lens (geology) , beam (structure) , thermal , diode , laser beam quality , optoelectronics , laser beams , physics , meteorology
We report on a high conversion efficiency tunable laser at 426 nm by adopting an external frequency-doubling cavity pumped by a diode laser. For the frequency-doubling process at 426 nm, the major challenge of increasing the conversion efficiency is mode-match degradation originating from the severely thermal effect. Here, we find that the center of the equivalently thermal lens is not at the center of the nonlinear crystal. We minimize the variation of beam parameters of the Gaussian beam in the external cavity by optimizing the center of the thermal lens to beam waist. As a result, the mode-match degradation is reduced as the incident power is increased. Finally, a 405 mW blue light is obtained with the conversion efficiency of 81%.