Nonlinear optical properties and Q-switched laser application of a novel Mo_0.5Re_0.5S₂ ternary alloy material at 2 μm

Abstract

In this study, a novel ternary alloy using Mo 0.5 Re 0.5 S 2 as a saturable absorber (SA) is prepared by liquid phase exfoliation method and successfully applied to a passively Q-switched Tm:YAlO 3 (Tm:YAP) bulk laser for the first time. The nonlinear SA effect of the prepared Mo 0.5 Re 0.5 S 2 SA at 2 μm is characterized using the open-aperture Z-scan technique and results in a saturable intensity of 5.62 μJ cm −2 and modulation depth of 7.92%. Using Mo 0.5 Re 0.5 S 2 as an SA, a 2 μm Q-switched Tm:YAP laser is realized, generating a maximum output power of 0.957 W with a shortest pulse width of 857.5 ns and a maximum repetition rate of 95 kHz. The corresponding single pulse energy and peak power are 10.1 μJ and 11.5 W, respectively. These achievements indicate that Mo 0.5 Re 0.5 S 2 could be an excellent and reliable SA for mid-infrared laser applications, and ternary transition metal disulfide alloys will bring new application opportunities to optoelectronic devices in the future.

Threshold decrease and output-power improvement in dual-loss Q-switched laser based on a few-layer WTe2 saturable absorber

“…aser diode (LD) pumped Q-switched lasers with a high peak power and a short pulse width have attracted much attention owing to their potential applications in laser material processing, laser medicine, and nonlinear frequency conversion, etc. 1,2) The pulse compression, threshold decrease, output-power increase, and operational stability of the Q-switched laser are important issues for researchers to consider. An active Q-switch is usually applied to obtain a pulse train with a given pulse-repetition rate, yet the output pulse is generally wide.…”