Sodium guide star laser generation by single-pass frequency doubling in a periodically poled near-stoichiometric LiTaO3 crystal

We report in this work a continuous wave (CW) narrowband 589 nm light generation for the purpose of laser guide assisted adaptive optics. A 39 mm long 1 mm thick periodically poled near stoichiometric LiTaO3 crystal with duty cycle near 50% was fabricated using electrical poling at room temperature and pumped by a Raman fiber amplifier. We tested two temperature control ovens, and a maximum conversion efficiency of about 14.3%, corresponding to 4 W of yellow light with 28 W of fundamental power, and bandwidth less than 0.18 GHz was achieved.