High-power passive Q-switching performance of a Yb:YCa₄O(BO₃)₃ laser with a few-layer Bi₂Te₃ topological insulator as a saturable absorber

Abstract

We demonstrate multi-watt passively Q-switched operation induced by a few-layer Bi2Te3 topological insulator saturable absorber, in an Yb:YCa4O(BO3)3 laser under high output couplings. An average output power of 3.85 W at pulse repletion rate of 400 kHz is produced at an incident pump power of 16.7 W with a slope efficiency of 28%; the resulting pulse energy, duration, and peak power are respectively 9.63 μJ, 96 ns, and 100.3 W. Our work shows the great potential of Yb:YCa4O(BO3)3 and other Yb-doped rare-earth calcium oxyborates crystals in the development of high-power, high-repetition-rate, short-duration, passively Q-switched solid-state lasers in the 1-μm region with 2D topological insulators acting as saturable absorbers.