Efficient second-harmonic generation from polarized thulium-doped fiber laser with periodically poled MgO:LiNbO3

•Frequency doubling a thulium-doped fiber laser for efficient 963 nm generation is presented.•A 50-mm-long periodically poled MgO:LiNdO3 crystal is used as the nonlinear material.•A high-power all-fiber polarized thulium-doped MOPA system is used as the seed source.•The frequency doubling efficiency is up to 56%, and the total optic-to-optic conversion efficiency is more than 12.9%.•The third- and fourth-harmonic generations from the thulium-doped fiber have been observed.

We present an efficient method for polarized 963 nm emission based on second-harmonic generation from a high-power, polarized thulium-doped fiber laser using periodically poled MgO:LiNbO3 as the nonlinear material. The maximum 963-nm output power of 710 mW has been achieved with a pulse duration of 34 ns at the repetition rate of 100 kHz and a Gaussian spatial beam profile. The frequency doubling efficiency is up to 56%, and the total optic-to-optic conversion efficiency is more than 12.9%. In addition, third- and fourth-harmonic generations have been observed.