外腔谐振倍频8.7W连续单频绿光技术研究

Technical Study of 8.7 W Continuous Wave Single Frequency Green Laser Based on Extra-Cavity Frequency Doubling

基于Pound—Drever-Hall外腔谐振倍频技术，实现了单频、连续1064nm基频光的高效倍频转换。精确锁定环形倍频腔腔长，利用I类非临界相位匹配三硼酸锂晶体获得了最高8．73W的倍频绿光输出，倍频效率为68．9％。在此基础上，研究了倍频绿光的波长锁定与调谐特性，当30min内波长锁定均方根值小于3fm时，实现了输出绿光波长在532．15～532．50nm范围内的连续可调。采用自外差拍频法测量了单频绿光的光谱特性，谱线线宽为18．7kHz，光束质量因子为1．25，光束质量优异。

Highly effective frequency doubling conversion of continuous wave, single frequency 1064 nm fundamental laser is realized based on the Pound-Drever-Hall extra-cavity frequency doubling technique. When the length of the ring frequency doubling cavity is accurately locked, the green laser output with the highest power of 8.73 W is obtained with the use of the type I noncritical phase matching lithium triborate crystal and the frequency conversion efficiency reaches 68.9%. Based on this, the green laser wavelength locking and tuning characteristics are investigated, and when the root-mean-square value of wavelength locking within 30 min is less than 3 fro, the wavelength is continuously tunable between 532.15 nm and 532.50 nm. The spectroscopic property of the single frequency green laser is measured by the self-heterodyne method, the measured line-width is 18.7 kHz, and the beam quality factor is 1.25 which indicates a superior beam quality.