外腔调谐的全固态Cr∶LiSAF激光器

由于调谐元件置于主腔外时,插入损耗影响小,可以扩展调谐范围,本文采用外腔棱镜和光栅调谐结构研制了全固态Cr∶LiSAF激光器。分析了外腔调谐结构的基本原理,分别选用棱镜和光栅作为调谐元件,研制了棱镜外腔调谐Cr∶LiSAF激光器和光栅外腔调谐Cr∶LiSAF激光器。分析对比了棱镜和光栅调谐的输出功率、光谱、调谐范围等特性以及镜片镀膜对输出特性的影响。进行了调谐实验,结果显示:选用棱镜作为外腔调谐元件时,在325mW的吸收泵浦功率下实现了785~985nm的调谐,输出功率最高达21mW。选用光栅作为调谐元件时,亦可实现785~985nm的调谐,最大输出功率为20mW,光谱的半峰全宽(FWHM)为0.12nm。得到的结果表明外腔全固态Cr∶LiSAF激光器可以实现窄线宽、宽谱调谐输出。

Widely tunable all-solid-state Cr:LiSAF lasers with external cavities

When tuning components are placed out of the main cavity structure in a tunable all-solid-state laser, it will has a smaller insertion loss and is conducive to extend the tuning range. This paper develops a all-solid-state Cr:LiSAF laser to realize its wide tunability. The principle of a external-cavity configuration was explored. A prism and a grating were chosen tunable elements, the Cr:LiSAF lasers with prism-controlled external cavity and the Cr:LiSAF laser with grating-controlled external cavity were presented. The tuning characteristics such as tuning ranges, spectra and output powers of the two kinds of lasers were studied and the effect of coating on their output characteristics was analyzed. Finally, the tuning characteristics of prism-controlled laser and grating-controlled laser were compared. The results under an absorption power of 325 mW show that the tuning range of the Cr:LiSAF laser with prism-controlled external cavity is 785-985 nm and its maximum output power is 21 mW. Moreover, the tuning range of the Cr:LiSAF laser with grating-controlled external cavity is also 785-985 nm, its maximum output power is 20 mW and the Full Width at Half Maximum (FWHM)is 0.12 nm. These results demonstrate that the tunable all-solid-state Cr:LiSAF lasers with external cavities realize narrower linewidths and wider tuning ranges.