High-energy, in-band pumped Q-switched Ho(3+):LuLiF(4) 2 microm laser

A Q-switched Tm:fiber-laser-pumped Ho:LuLiF(4) laser is reported that has been optimized for high-energy pulses at low repetition rates. Operating at 100Hz, a pulse energy of 24.8mJ with pulse widths of 47ns at a wavelength of 2052nm was achieved. The beam propagation factor (M(2)) was measured to be approximately 1.04 at the maximum pump power, confirming fundamental transverse mode (TEM(00)) operation. Starting the pump laser at maximum power, the pulse energies of each of the first 10 pulses are >47mJ. This strong influence of crystal temperature on laser performance is discussed with the prospect for further improvement of the laser efficiency.