Room temperature efficient continuous wave and Q-switched Ho:YAG laser double-pass pumped by a diode-pumped Tm:YLF laser

Abstract

We report the room temperature continuous wave and acousto-optically Q-switched Ho:YAG laser double-pass pumped by a diode-pumped Tm:YLF laser. Continuous wave output power of 10.5 W at 2090 nm is obtained under the incident pump power of 18.1 W, corresponding to a conversion efficiency of 58.0% and a slope efficiency of 65.7%. For the Q-switched regime the maximum pulse energy of 1.0 mJ and the minimum pulse width of 25 ns at the repetition rate of 10 kHz are achieved, resulting in a peak power of 40.0 kW.

A resonantly-pumped tunable Q-switched Ho:YAG ceramic laser with diffraction-limit beam quality

“…Last decade, resonantly pumped Ho-doped laser has attracted great attentions due to its low quantum defect and high efficiency. Ho:YAG single crystal has been widely studied to obtain continuous-wave(CW) and Q-switched operation in 2 μm wavelengths [6][7][8].…”

Diode-Pumped Ho-Doped KLu(WO4)2Laser at 2.08 µm

“…Direct excitation using resonant or in-band pumping of the 5 I 7 excited level of Ho at $1:9 m offers the advantages of high quantum efficiency for the $2:1 m laser transition and minimal heat load to the active element, both important prerequisites for power scaling in this spectral range. The resonant pumping of Ho lasers by separate Tm lasers in continuous-wave (CW) or Q-switched regimes has been extensively studied, including several Tm crystal [2][3][4][5][6] and fiber [7][8][9][10] lasers. However, these Tm lasers, being diodepumped near 800 nm, lead to a low overall efficiency of such cascaded pump schemes.…”

Resonantly pumped tunable Ho:YAG laser

“…The typical wavelength of the Ho:YAG laser corresponding to the CO 2 absorption peak in the atmosphere is 2097 nm [15,16]. For other applications the wide bandwidth of Ho crystals emission (2000 -2200 nm) seems to be more appropriate [17,18].…”