Black phosphorus based saturable absorber for Nd-ion doped pulsed solid state laser operation

In this paper, the use of black phosphorus (BP) as a saturable absorber in a Q-switched Nd-ion doped solid state laser is presented. Few layers of BP in isopropyl alcohol are obtained by liquid phase exfoliation. The BP nanosheets with thicknesses in the range of 15-20 nm are deposited onto a K9 glass substrate. By inserting the BP nanosheets into a diode pumped Nd-ion doped solid state laser, stable Q-switched lasing at 0.9, 1.06, 1.3 mu m is obtained. Using this approach, we have achieved a short pulse duration down to 219 ns, a high pulse energy of up to 6.5 mu J, and the corresponding peak power of 30 W. Our results show that the BP saturable absorber functions well in a Nd-ion doped solid state laser for pulsed laser generation.