A passively Q-switched operation of Tm:YAP laser with a Nb2AlC-based saturable absorber

As a new two-dimensional MXene material, Nb2AlC has a wide range of applications due to its superior optical, physical, and chemical properties. In this paper, we prepared a Nb2AlC-based saturable absorber (SA) and demonstrated its nonlinear absorption performances by a 2-μm scope nanosecond laser. Based on Nb2AlC SA, an 1.62-W average output power and a 850-ns pulse duration at 135 kHz were obtained from a passively Q-switched Tm:YAP (PQS) laser with a 10.34-W pump power, and a 12.00-µJ pulse energy was achieved in the experiment, corresponding to a central output wavelength of 1987.2 nm and an optical-optical conversion efficiency of 13.5%. In addition, beam quality factors less than 1.10 in x-axis direction and y-axis direction were achieved from the PQS Tm:YAP laser.