Yingxiong Qin, Xiahui Tang, Yu Xiao, Juan Liu, Du Wang, Hao Peng, Qiansong Deng, Xiao Zhu, Zhengjia Li
Wuhan National Laboratory for Optoelectronics, National Engineering Research Center for Laser Processing, School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Hubei, China.
Opt Lett. 2009 Apr 1;34(7):1120-2. doi: 10.1364/ol.34.001120.
A new type of toric concave mirror laser resonator with a big Fresnel number is presented. The M2 factor of an output laser beam of the new resonator with a Fresnel number of 8.05 is close to that of the plane-concave stable resonator with a Fresnel number of 2.01, the volume of output mode of the new resonator is about four times of that of the plane-concave stable resonator. A 3.2 kW doughnut-like laser beam with an M2 factor of 1.9 is obtained experimentally by using the new resonator on a high-power transverse flow CO2 laser, while the similar laser power with an M2 factor of 7.5 is obtained by using a plane-concave stable resonator with the same Fresnel number. Results show that a toric concave mirror laser resonator can permit operation of the laser with high power and high beam quality mode in the laser with large gain volume.
提出了一种新型的具有大菲涅尔数的复曲面凹面镜激光谐振腔。菲涅尔数为8.05的新型谐振腔输出激光束的M²因子接近于菲涅尔数为2.01的平凹稳定谐振腔的M²因子，新型谐振腔的输出模式体积约为平凹稳定谐振腔的四倍。在高功率横向流动CO₂激光器上使用新型谐振腔，通过实验获得了一束M²因子为1.9的3.2kW环形激光束，而使用具有相同菲涅尔数的平凹稳定谐振腔获得了M²因子为7.5的类似激光功率。结果表明，复曲面凹面镜激光谐振腔能够使增益体积大的激光器以高功率和高光束质量模式运行。
