Research Of 2μm All-solid-state Passive Q-switched Laser Based On Ternary Materials Saturable Absorbers

At present,pulsed lasers play an indispensable role in various industries Ultra-short pulsed lasers obtained through modulation have the advantages of short width,high peak power,and broad spectrum.Ultrafast pulsed laser spectroscopy has been widely used in optical technologies,such as military,industrial,biomedical,and modern wireless communications.At present,the most effective way to obtain short-pulse lasers is through Q-switched and mode-locked technologies.These two methods have the advantages of simple operation and low cost.Saturable absorber is an important ultra-short pulse modulation element in passive Q-switching,and its application and development have attracted a lot of attention.At present,due to the continuous development and maturity of science and technology,the requirements of pulsed laser parameters have been more stringent in different fields.The main factor restricting the application and development of 2μm pulse laser is the modulation device-saturable absorber.In this paper,Tm:YAP crystals were used as gain media to study the Q-switched optical modulation characteristics of two novel saturable absorbers,Mo0.sRe0.5S2 and Ta2NiSe5.The main research contents are as follows1.The Mo0.5Re0.5S2 was used as a saturable absorber to achieve passive Q-switching of all solid-state Tm-doped laser.Mo0.5Re0.5S2 saturable absorber was prepared by liquid phase exfoliation method;it was applied to all-solid-state lasers,and the prepared Mo0.5Re0.5S2 saturable absorber was characterized by using the open-aperture Z-scann technology,The nonlinear saturable absorption characteristics were measured,and all-solid-state laser was passively Q-switched to achieve a minimum pulse width of 857.5ns and an output power of 957mW at 2μm.The research proved that the optical modulation capability of Mo0.5Re0.5S2 and application potential in solid-state pulsed lasers.2.A novel two-dimensional ternary chalcogenide Ta2NiSe5 was made into a saturable absorber by the liquid phase exfoliation method,its nonlinear absorption characteristics are characterized,and it was successfully applied for the first time in passive Q-switching of Tm:YAP all-solid-state laser.In Q-switched state,the maximum output power is 451mW,the corresponding slope efficiency is 17.4%,the shortest pulse width is 740ns,and the maximum repetition frequency is 71kHz.The calculated single pulse energy is as high as 6.35μJ,and the peak power is as high as 8.58W.The results show that the multilayer Ta2NiSe5 is expected to become a reliable and feasible saturable absorber,which can generate a pulsed laser near 2μm.