Superior performance of a 2 kHz pulse Nd:YAG laser based on a gradient-doped crystal
Meng’en Wei, Tingqing Cheng, Renqin Dou, Qingli Zhang, Haihe Jiang
Abstract
Herein, we report a homemade new Nd:YAG crystal rod that contains a gradient dopant of 0.39–0.80 at.% <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mi>Nd</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> from end to end, achieving superior performance of a 2 kHz Nd:YAG pulse laser at 1064 nm. The optical-to-optical conversion efficiency reached 53.8%, and the maximum output power of the laser was 24.2 W, enhanced by 35.9% compared with a uniform crystal rod with the same total concentration of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mi>Nd</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> . Significantly, our experiments revealed that the gradient concentration crystal produced a relatively even pumping distribution along the rod axis, greatly reducing the temperature gradient as well as having a smaller thermal effect. The pump and thermal distribution smoothing obviously improved the features of laser oscillation and output.