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

Abstract

We demonstrated a Q-switched Ho:YAG ceramic laser operating at 2097 nm. The Ho:YAG ceramic laser was resonantly pumped by a Tm:YLF laser at 1908 nm. The laser performance with two Ho-doping concentrations of Ho:YAG ceramics in a U-shaped resonator was studied. Different pump spots were investigated to obtain high extract efficiency. The wavelength of Ho:YAG ceramic laser was tuned from 2090.70 nm to 2098.10 nm. The Q-switched pulse energy were 9.6 mJ at a pulse repetition frequency (PRF) of 200 Hz and 10.2 mJ at a PRF of 100 Hz, respectively. The beam quality M(2) factors were measured to be less than 1.1 in both directions.

In-Band Pumped High Power Ho:YAG Ceramic Laser by a Tm:YLF Laser

“…In 2012, Yang et al proved a Ho:YAG ceramic slab in-band pumped by a Tm:fiber laser and the maximum output power of 5.74 W with a central wavelength of 2097 nm was obtained. [14] In 2014, Wang et al demonstrated a resonantly-pumped tunable Q-switched Ho:YAG ceramic laser at 2097 nm by a Tm:YLF solid-state laser, and the maximum cw output power was 4.48 W. [15] In the present study, we demonstrate a high power Ho:YAG ceramic laser operating at 2091 nm reso-nantly pumped by a Tm:YLF laser. A cw output power up to 26.8 W was obtained, which is, to the best of our knowledge, the highest cw output power produced by a Ho:YAG ceramic laser.…”

Q-Switched 2 Micron Solid-State Lasers and Their Applications

“…In 2014, Wang et al used a 1.908 μm Tm:YLF solid-state laser as the pump source to realize an actively Q-switched Ho:YAG ceramic laser at 2.097 μm based on an AO Q-switch. The maximum pulse energy and minimum pulse width were 10.2 mJ and 83 ns at the repetition rate of 100 Hz [36]. In 2016, Ji et al used a 1.94 μm LD as the pump source to realize an actively Q-switched Ho:YLF solid-state laser based on an AO Q-switch at 2.06 μm.…”

Polycrystalline Ho: LuAG laser ceramics: Fabrication, microstructure, and optical characterization

“…Solid‐state lasers based on 5 I 7 → 5 I 8 transition of Ho 3+ ions operate in 2 μm eye‐safe spectral range and have significant applications in optical communication, laser ranging, laser surgery, and mid‐IR generation via pumping optical parametric oscillator lasers . For the past few years, Ho 3+ ‐doped yttrium aluminum garnet (YAG) has been intensively studied . Ho:Lu 3 Al 5 O 12 (LuAG) is another kind of garnet sharing the same structure of Ho:YAG, which can be obtained by replacing Y with Lu in the dodecahedral sites.…”

“…[1][2][3][4] For the past few years, Ho 3+doped yttrium aluminum garnet (YAG) has been intensively studied. [5][6][7][8] Ho:Lu 3 Al 5 O 12 (LuAG) is another kind of garnet sharing the same structure of Ho:YAG, which can be obtained by replacing Y with Lu in the dodecahedral sites. Spectroscopy studies have shown that Ho:LuAG possesses a lower thermal occupation of lower laser levels, which is beneficial for laser operating at~2.1 lm.…”