Diode-pumped Er3+:Yb3+:NaCe0.43Gd0.57(WO4)2 pulse laser passively Q -switched with a Co2+:Mg0.4Al2.4O4 saturable absorber at 1.53 μ m

Abstract

Based on the long fluorescence lifetime of upper laser level 4I13/2 of Er3+ ions and high 1.5−1.6 μm laser operation efficiency, an Er3+:Y b3+:NaCe0.43Gd0.57(WO4)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 Er3+ and Y b3+ co-doped tungstate crystal, when a Co2+:Mg0.4Al2.4O4 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 c-cut 1.7-mm-thick Er3+:Y b3+:NaCe0.43Gd0.57(WO4)2 crystal.