高效率599 nm Ba(NO3)2外腔喇曼激光器

橘黄色波段固体激光器在基于荧光探测的生物医学诊断和显示等众多方面有着广泛的实际应用. 报道了利用532 nm的Nd∶YAG倍频激光抽运外置喇曼腔内的硝酸钡晶体,获得高效率的599 nm橘黄色喇曼激光的实验结果.对外置喇曼腔实验装置和运转参量进行了优化,喇曼振荡腔由对二阶斯托克斯光有最优化反射率的腔镜构成,对实验中所得到的二阶斯托克斯喇曼激光脉宽压缩及出现双尖峰的现象进行了分析.当抽运光功率达到4.1 W时,获得二阶斯托克斯喇曼激光功率为710 mW,输出光中心波长为599.38 nm,半峰全宽（FWHM）为1.1 nm,激光器最大光光转换效率为17.5%,斜率效率为24.8%.

High Efficiency 599 nm Ba(NO3)2 Raman Laser in External Resonator

The solid-state lasers in the yellow-orange region of the spectrum have a variety of promising applications in biomedical diagnostic (based on fluorescence detection) and display. Operation of a high efficient 599 nm yellow-orange Raman laser with a Ba(NO3)2 crystal in the external Raman cavity pumped by the harmonic of Nd∶ YAG laser (532 nm) was reported. Barium nitrate crystal was grown by the aquasolution cooling method with the length of 48 mm long. To achieve conversion efficiency about the theoretical limit,the parameters of pump laser and external Raman cavity were optimized. The Raman cavity was composed of diachronic mirrors with optimal reflectivity for the second Stokes wavelength. The use of the external cavity with optimal reflectivity output coupler reduced the threshold pump intensity and increased overall efficiency with respect to single pass cell. The second Stokes Raman laser' s pulse compression phenomenon and two little peaks temporal behaviour were recorded and analysed. When the pump laser was operated at laser power of 4.1 W,the maximum second Stokes Raman output power of 710mW was obtained with FWHM of 1.1 nm at output wavelength of 599.38 nm,and the maximum conversion efficiency of 17.5% was observed. The slope efficiency was calculated as 24.8%.