High average power 1314 nm Nd:YLF laser, passively Q-switched with V:YAG

Abstract

A 1314 nm Nd:YLF laser was designed and operated both CW and passively Q-switched. Maximum CW output of 10.4 W resulted from 45.2 W of incident pump power. Passive Q-switching was obtained by inserting a V:YAG saturable absorber in the cavity. The oscillator delivered a maximum of 825 μJ energy per pulse, with a pulse duration of 135 ns at a pulse repetition frequency of 6.3 kHz, effectively delivering 5.2 W of average power.

High average power Q-switched 1314 nm two-crystal Nd:YLF laser

“…The most efficient CW operation as well as highest output power was achieved with a 10% OC with a resulting incident optical-to-optical slope efficiency of 25%. This laser had an incident pump power threshold of 15.3 W and a maximum power output of 26.5 W, which is 2.5 times higher than what was recently reported by our group [14]. Wavelength measurements showed oscillation only at 1314 nm on the σ-polarization due to the oscillator being unstable for the stronger negative thermal lenses associated with the π-polarization [5,6].…”

“…We previously reported the highest 1.3 µm Continuous Wave (CW) output power from a diode-end-pumped Nd:YLF laser of 10.4 W and also the highest energy per pulse of 825 µJ for a passively Q-switched Nd:YLF 806 nm end-pumped setup [14]. Recent 1.3 µm Nd:YLF work by other groups based on side-pumped setups delivered CW powers of up to 14.9 W [15] and for actively Q-switched Nd:YLF pumped at 796 nm average powers of up to 12.3 W (from 180 W of pump power) with corresponding pulse energies of 3.8 mJ [16].…”

Efficient dual-wavelength Nd:LuLiF_4 laser

“…A well-known representative of fluoride crystal is Nd 3 -doped YLiF 4 , which has been widely used both in research and commercial devices [6,7]. In practice, 1.32 and 1.31 μm dual-wavelength operation has not been realized in Nd:YLF crystal, and Nd:YLF laser only oscillated at 1.31 μm on σ polarization in a high pump level due to strong negative thermallensing effect associated with the π polarization [8] or 1.32 μm on π polarization with complex cavity setup [9]. Another fluoride crystal Nd:LuLiF 4 (Nd:LLF), like its isomorphs YLF, has emerged as a new promising laser crystal for diode pumping.…”

“…Another fluoride crystal Nd:LuLiF 4 (Nd:LLF), like its isomorphs YLF, has emerged as a new promising laser crystal for diode pumping. Compared with Nd:YLF, Nd:LLF has several advantages; for instance, larger-emission cross section 5.1 × 10 −20 cm 2 for π and 2.2 × 10 −20 cm 2 for σ at 1.3 μm (Nd:YLF, 2-2.5 × 10 −20 cm 2 for the two polarizations [8]), and comparably long fluorescence lifetime of 489 μs [10]. Usually, the heat generation of 1.3 μm laser is more serious than lasing at 1.0 μm due to larger quantum defect.…”

“…It has been demonstrated that V 3 :YAG can be an excellent saturable absorber (SA) for Nd lasers operated in the 1.3 μm [8,[15][16][17][18][19]. However, V 3 :YAG has not been used to passively Q-switched Nd:LLF at either 1.0 or 1.3 μm.…”