Comparative study of pulsed laser diode end-pumped thulium-doped 2-μm Q-switched lasers*

Abstract

We report pulsed laser diode (LD) end-pumped acoustic Q-switched Tm:YAG laser, Tm:LuAG laser, and Tm:LuYAG laser and the physical properties and spectra of Tm:YAG, Tm:LuAG, and Tm:LuYAG are analyzed. The Tm:LuYAG laser is pumped by 785-nm and 788-nm pulses separately, and is compared with Tm:YAG laser. Different output energy values and output wavelengths of Tm:LuAYG lasers pumped by LDs with different wavelengths are obtained and compared with each other. When the repetition frequency is 100 Hz, the pulsed Tm:YAG laser has single pulse energy of 15.9 mJ, pulse width of 126.7 ns, and the center wavelength of 2013.36 nm, and the pulsed Tm:LuAG laser possesses single pulse energy of 11.8 mJ, pulse width of 252.4 ns, and the center wavelength of 2023.65 nm, and the pulsed Tm:LuYAG laser output energy values are 12.32 mJ and 12.25 mJ with the slope efficiencies of 12.5% and 11.85%, the center wavelengths of 2017.89 nm and 2027.11 nm, respectively, while the pump sources are 785-nm and 788-nm pulsed LDs, respectively.