Radially polarized and pulsed output from passively Q-switched Nd:YAG ceramic microchip laser.
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.
Li
Jian-lang
JL
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China. apuli@siom.ac.cn
Ueda
Ken-ichi
K
Musha
Mitsuru
M
Zhong
Lan-xiang
LX
Shirakawa
Akira
A