Li Jian-lang, Ueda Ken-ichi, Musha Mitsuru, Zhong Lan-xiang, Shirakawa Akira
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China.
Opt Lett. 2008 Nov 15;33(22):2686-8. doi: 10.1364/ol.33.002686.
For the first time, to the best of our knowledge, a radially polarized laser pulse was produced from a passively Q-switched Nd:YAG ceramic microchip laser with a piece of Cr4+:YAG crystal as the saturable absorber and multilayer concentric subwavelength grating as the polarization-selective output coupler. The averaged laser power reached 450 mW with a slope efficiency of 30.2%. The laser pulse had a maximum peak power of 759 W, a minimum pulse duration of 86 ns, and a 6.7 kHz repetition rate at 3.7 W absorbed pump power. The polarization degree of the radially polarized pulse was measured to be as high as 97.4%. Such a radially polarized laser pulse with a high peak power and a short width is important to numerous applications such as metal cutting.
据我们所知，首次利用一块Cr4+:YAG晶体作为可饱和吸收体、多层同心亚波长光栅作为偏振选择输出耦合器，从被动调Q的Nd:YAG陶瓷微芯片激光器产生了径向偏振激光脉冲。平均激光功率达到450 mW，斜率效率为30.2%。在3.7 W的吸收泵浦功率下，激光脉冲的最大峰值功率为759 W，最小脉冲持续时间为86 ns，重复频率为6.7 kHz。测得径向偏振脉冲的偏振度高达97.4%。这样一个具有高峰值功率和窄宽度的径向偏振激光脉冲对诸如金属切割等众多应用而言非常重要。
