Diode-pumped Er~(3+):Yb~(3+):NaCe_(0.43)Gd_(0.57) (WO_4)_2 pulse laser passively Q-switched with a Co~(2+):Mg_(0.4)Al_(2.4)O_4 saturable absorber at 1.53 μm

摘要

Based on the long fluorescence lifetime of upper laser level ~4I_(13/2) of Er~(3+) ions and high 1.5-1.6 μm laser operation efficiency, an Er~(3+):Yb~(3+):NaCe_(0.43)Gd_(0.57)(WO_4)_2 crystal was used to generate a Q-switched pulse laser with high energy and low threshold. End-pumped by a 970 nm diode laser, a passively Q-switched 1.5-1.6 μm pulse laser was first realized in an Er~(3+) and Yb~(3+) co-doped tungstate crystal, when a Co~(2+):Mg_(0.4)Al_(2.4)O_4 spinel crystal was used as saturable absorber. A 1.53 μm pulse laser with about 22 μJ energy, 76 ns duration and 21 kHz repetition rate was obtained at an absorbed pump power of 12 W in a ccut 1.7-mm-thick Er~(3+):Yb~(3+):NaCe_(0.43)Gd_(0.57)(WO_4)_2 crystal.