Temperature field of nonlinear crystal eccentric-radiated by intra-cavity multi-mode beam

LIU Xiao-jian; LI Long; DU Chang-long; SHI Xia; SHI Peng; GAN An-sheng

doi:10.3969/j.issn.1001-3806.2012.01.016

In order to improve the frequency doubling conversion efficiency of nonlinear crystal influenced by non-uniform temperature rise in high power green lasers,the temperature performance of nonlinear crystal with intracavity multi-mode frequency doubling was analytically investigated.According to the actual characteristics of nonlinear crystal with intra-cavity frequency doubling,based on the heat conduction equation,a general analytical expression of temperature field in nonlinear crystal eccentric-radiated by multi-mode fundamental wave was obtained.The result shows that when the waist spot radius of multi-mode light beam is 200μm,the power of fundamental wave is 500W,and the maximum temperature rise of KTP crystal eccentric-radiated(eccentric degree ξ=0.33)by fundamental harmonic is 79.80℃,4.0% lower than the maximum temperature rise 83.14℃ of KTP crystal center-radiated by fundamental harmonic with other conditions keeping the same.When the radiation eccentricity increases,the maximum temperature rise of KTP crystal can be effectively reduced.The thermal model of nonlinear crystal meets the actual requirement of green lasers,which will play an instructive role in elimination of nonlinear crystal heating effect and improvement of the harmonic conversion efficiency of nonlinear crystal.

Temperature field of nonlinear crystal eccentric-radiated by intra-cavity multi-mode beam

Corresponding author: LI Long, lilong7211@126.com;

1. Faculty of Science, Xi'an University of Architecture & Technology, Xi'an 710055, China;

2. Institute of Applied Physics, Xi'an University of Architecture & Technology, Xi'an 710055, China

Received Date: 2011-04-22

Accepted Date: 2011-06-16

Available Online: 2012-01-25

Abstract: In order to improve the frequency doubling conversion efficiency of nonlinear crystal influenced by non-uniform temperature rise in high power green lasers,the temperature performance of nonlinear crystal with intracavity multi-mode frequency doubling was analytically investigated.According to the actual characteristics of nonlinear crystal with intra-cavity frequency doubling,based on the heat conduction equation,a general analytical expression of temperature field in nonlinear crystal eccentric-radiated by multi-mode fundamental wave was obtained.The result shows that when the waist spot radius of multi-mode light beam is 200μm,the power of fundamental wave is 500W,and the maximum temperature rise of KTP crystal eccentric-radiated(eccentric degree ξ=0.33)by fundamental harmonic is 79.80℃,4.0% lower than the maximum temperature rise 83.14℃ of KTP crystal center-radiated by fundamental harmonic with other conditions keeping the same.When the radiation eccentricity increases,the maximum temperature rise of KTP crystal can be effectively reduced.The thermal model of nonlinear crystal meets the actual requirement of green lasers,which will play an instructive role in elimination of nonlinear crystal heating effect and improvement of the harmonic conversion efficiency of nonlinear crystal.

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Reference (14)

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Temperature field of nonlinear crystal eccentric-radiated by intra-cavity multi-mode beam

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