Gold Nanocages as Saturable Absorbers for Passively Q-Switched Nd:YVO4 Lasers with Optimized Performance

Abstract

Based on a gold nanocage saturable absorber (GNC-SA) with the surface plasmon resonance (SPR) absorption peak located at 1.06 μm, passively Q-switched Nd:YVO4 lasers with a center wavelength of 1064.1 nm were demonstrated. Q-switched pulses with the shortest pulse duration of 143 ns and a pulse repetition rate of 467 kHz were achieved at transmittance T = 4% under a pump power of 5.98 W. Under a pump power of 3.95 W, the maximum average output power of 372 mW was obtained at a laser with transmittance of 10.8%, corresponding to an optical conversion efficiency of 9.4% and a slope efficiency of 14.1%. Our results reveal that for passively Q-switched lasers at a given wavelength, we are able to synthesize the most suitable GNC-SA to obtain the best output characteristics of lasers.