Abstract:We demonstrated continuous-wave (CW) and Q-switched operation of a room-temperature Ho:YAlO 3 laser that is resonantly endpumped by a diode-pumped Tm:YLF laser at 1.91 μm. The CW Ho:YAlO 3 laser generated 5.5 W of linearly polarized ( E c ∥ ) output at 2118 nm with beam quality factor of M 2 ≈ 1.1 for an incident pump power of 13.8 W, corresponding to optical-to-optical conversion efficiency of 40%. Up to 1-mJ energy per pulse at pulse repetition frequency (PRF) of 5 kHz, and the maximum average power of 5.3-W with FWHM pulse duration of 30.5 ns at 20 kHz were achieved in Q-switched mode.

Abstract:In this letter we report a diode-pumped single frequency Tm:LuAG laser at room temperature. One uncoated fused silica etalon (0.1 mm) and one uncoated YAG etalon (1 mm) are employed to narrow the laser line-width. Single frequency laser is achieved by tuning the angle of the etalons. The oscillating wavelength can be changed (from 2018 to 2030 nm) and at each wavelength, single-frequency laser is achieved. The maximum single frequency laser power is up to 148.0 mW with the central wavelength of 2026.4 nm. To our knowledge, this is the first time to obtain single-frequency Tm:LuAG laser of up to 148.0 mW with Fabry-Perot etalons in the cavity.Output power, mW

Acousto-optically Q-switched operation of Tm (5 at. %), Ho(0.5 at. %):GdVO4 laser was reported in this paper. The Tm,Ho:GdVO4 crystal was cooled by liquid nitrogen and end-pumped by a 13.6 W fiber-coupled laser diode at 794 nm. Average power of 3.9W was obtained at pulse repetition frequency (PRF) from 10 to 50 kHz, with corresponding to optical-to-optical conversion efficiency of 29 %, and slope efficiency of 35%. The highest energy per pulse of 1.1 mJ in 23 ns was achieved at 3 kHz with peak power of 46 kW.

A stable diode-pumped passively Q-switched Tm,Ho:YVO4 laser with Cr:ZnS saturable absorber is reported. The shortest pulse duration of ∼500 ns with the central wavelength of 2041 nm is obtained at the pump power of 7.4 W, corresponding to the pulse energy of 3.5 𝜇J at repetition rate of 65 kHz.

We demonstrated a diode-pumped tunable single-longitudinal-mode Er:YAG laser using a twisted-mode technique at 1.6 μm. The maximum single-longitudinal-mode output power of 315 mW was obtained at 1645.3 nm, corresponding to a slope efficiency of 7.7%. The singlelongitudinal-mode laser has a beam quality factor of M2 ~ 1.07. The output wavelength can be tuned from 1644.8 to 1646.1 nm by changing the etalon angle. In addition, by changing an output coupler, a maximum single-longitudinal-mode output power of 130 mW at 1617.2 nm with a slope efficiency of 3.3% was also achieved. The output wavelength can be tuned from 1616.9 to 1617.4 nm by changing the etalon angle. The twisted-mode Er:YAG laser operated at single-longitudinal mode is being reported for the first time to the best of our knowledge.