High Peak Power Erbium Lasers Resonantly Pumped by Fiber Lasers

摘要

Challenges typically associated with efficient operation of bulk solid-state erbium lasers operating on the eyesafe (~4I_(13/2) → ~4I_(15/2)) transition have been effectively overcome using a high-brightness fiber laser as a pump source. We report exceptional performance in a variety of laser hosts resonantly pumped by a cw, high-average-power erbium fiber laser. Herein we present results from resonantly pumped erbium-doped YAG, LuAG, YLF, YAlO_3, and YVO_4, in cw and repetitively Q-switched operation. Most notable results include 9.5 W of near-diffraction-limited output from an Er:YAG laser at 1.645 μm, Q-switched at 10 kHz with 40 ns pulsewidth (25 kW peak power) as well as 3.4 mJ/pulse with 21 ns pulses at 1.1 kHz (160 kW peak). We have achieved overall optical conversion efficiency greater than 50% with incident slope efficiency >60%. This is, to our knowledge, the highest performance (average power and conversion efficiency) obtained from a bulk solid-state Q-switched erbium laser. To demonstrate the utility of such sources, we also present results from second harmonic generation to 822nm, as well as a periodically poled lithium niobate optical parametric oscillator generating tunable 2.5 - 3.8 micron output.