一种V型固体激光腔的热动力图解分析

Thermal dynamical graphic analysis of a V type solid laser resonator

采用图解分析方法分析一种常用于内腔倍频V型折叠固体激光腔在热透镜作用下的工作特性;得到谐振腔两臂中的光模参数bt,b2及束腰尺寸wt,w2随激光介质的焦距ft的变化关系.结果表明:这种谐振腔具有较宽的热稳定范围,而且在ft=l0处未出现无法运行的高损耗区;其热稳定范围及基模光斑尺寸可通过调整腔参数来改变,其关键参数为第一臂的长度l0+f,在选定腔镜的前提下,l0+f愈小,热稳定范围愈宽,同时wt愈小.在腔内插入一定厚度的布儒斯特片可以部分消除腔的像散.

To analyze the working characteristic under the effect of thermal lens of laser medium of a V type folded laser resonator, a graphic analyze method is used. Relationship of laser mode parameters bt, b2 and beam waists wt, w2 varies from focal length of thermal lens were obtained. The results have shown this type of resonator has a wider thermal stable range compare with other similar resonator, and no high loss region when the dynamics factor ft approaches l0. The stable range and beam radius can be changed by adjusting the parameter of resonator. And the length l0 ＋ f of first arm is a key parameter, for given parameters of resonator mirrors, the shorter l0 ＋ f, the wider thermal stable range, and smaller wt is. The resonator astigmatic can be compensated by inserting a suitable thickness Brewster plate in the cavity.