皮秒激光中KTP晶体灰迹对二次谐波转换效率的影响  

Effect of the gray-tracking in KTP crystal on the SH conversion efficiency by using ps pulse

作　　者：吴逢铁[1] 张文珍[1] 姚关清[1] 

机构地区：[1]华侨大学信息科学与工程学院,泉州362011

出　　处：《激光杂志》2004年第1期11-12,共2页Laser Journal

基　　金：国务院侨办科研基金资助 (0 1QZR0 3 )

摘　　要：高功率激光在KTP晶体中引起的“灰迹”(gray -tracking)现象 ,影响了二次谐波转换效率的进一步提高。本文利用凸 -ARR非稳腔产生的皮秒光脉冲比较和研究了KTP和BBO晶体的倍频转换效率 ,分析KTP灰迹形成对转换效率的影响。腔外倍频实验中 ,分别获得 43 .8%和 3 2 %的转变效率 ;当采用腔内倍频方式 ,其转换效率分别为 5 3 .4%和 70 %。结果指出 :在较低的激光功率下 (小于KTP灰迹产生阈值 )KTP的转换效率高于BBO晶体 ;而在高功率密度情况下 ,由于KTP灰迹的产生 ,使它的倍频转换效率低于BBO晶体。KTP gray-tracking caused by the high power laser limits the further increase of the second harmonic conversion efficiency.Using a pico-second laser pulse generated by a convex-ARR unstable resonator Nd:YAG laser to study the SHG of the KTP and BBO crystals.The influence of KTP gray tracking on the SH conversion efficiencies is analyzed.In the experiment ,the conversion efficiencies 43.8% and 32% for extra-cavity frequency doubling,53.4% and 70% for intra-cavity frequency doubling are obtained,respectively.It shows that at lower power density (below the threshold of KTP gray-tracking),the SH efficiency in KTP is higher than that in BBO crystal;but for the high power density,the conversion efficiency in KTP becomes lower compared to BBO crystal since the KTP gray-tracking generated.

关 键 词：皮秒激光 KTP晶体 灰迹 二次谐波转换效率 BBO晶体 

分 类 号：TN248[电子电信—物理电子学]