Passively Q-switched laser based on gold nanobipyramids as saturable absorbers in the 1.3 μm region

We demonstrate a passively Q-switched solid-state laser operating at the central wavelength of 1342  nm based on gold nanobipyramids (Au-NBPs) as saturable absorber (SA) for the first time. Au-NBPs are fabricated through a seed-mediated growth method, and placed in a simple linear cavity. Under an absorbed diode-pumped power of 5.339  W, an average power of 175  mW was generated with a minimum pulse width of 342  ns and a repetition rate of 141.8  kHz, corresponding to a pulse energy of 1.23  μJ.