Passively Q-switched Nd:YAG/Cr~(4+):YAG micro laser with high beam quality

摘要

Laser diode end-pumped passively Q-switched Nd:YAG/Cr~(4+):YAG micro lasers, with short pulse width, high repetition rate, high peak power and compact structure, have widely applications in laser mico processing, optical communication, laser radar, medical and other fields. But its beam quality is not excellent because of short resonant cavity, thermal effect of crystal, and pump laser. The beam quality is promoted in this paper by compressing the pump beam size and confirming the best position of pump beam focus in crystal. The repletion rate of laser is 20kHz. The output single pulse energy is 18.2μJ and pulse width is 1.23ns. The beam quality of laser is M~2=1.18.