A high stability and low noise passively Q-switched yellow-green laser with a Ti3C2Tx-PVA saturable absorber

Abstract

An 808 nm laser diode (LD) end-pumped passively Q-switched Nd: YAG ceramic yellow green laser at 561 nm with high stability and low noise has been demonstrated, for the first time to our knowledge based on passively Q-switching with a Ti3C2Tx-polyvinyl alcohol (Ti3C2Tx-PVA) film, frequency selection and filtering with a Brewster polarizer (BP) and a birefringent crystal (BC), and intracavity frequency doubling with a LiB3O5 (LBO) crystal. The 1112 nm and 1116 nm wavelengths from the Nd: YAG ceramic and the number of longitudinal modes of 1123 nm fundamental frequency light were effectively suppressed by adopting BP and BC. At 5.1 W of the 808 nm LD pump power, the 561 nm-PQYG laser with a maximum average power of 75.5 mW, a maximum repetition rate of 610 kHz, and a narrowest pulse width of 41 ns were obtained, corresponding to an average power instability of ±0.29%, a repetition rate instability ±7.08%, a pulse width instability of ±4.67%, and a laser noise of 0.49% over a period of 4 h.