Generation of Joule-level green bursts of nanosecond pulses from a DPSSL amplifier.

A new approach to generation of a burst of high-energy green pulses by placing a high-energy multi-slab Yb:YAG DPSSL amplifier and SHG crystal inside a regenerative cavity is presented. In a proof-of-concept test, stable generation of a burst of six green (515 nm) pulses, each 10 ns in duration and separated by 29.4 ns (34 MHz), with 2.0 J total energy has been demonstrated at 1 Hz from a non-optimized ring cavity design. A maximum individual green pulse energy of 580 mJ was produced from a 1.78 J circulating infrared (1030 nm) pulse (average fluence 0.9 J/cm), corresponding to a SHG conversion efficiency of 32%. Experimental results have been compared with predicted performance from a simple model. Efficient generation of a burst of high energy green pulses offers an attractive pump source for Ti:Sa amplifiers, providing the potential to reduce the impact of amplified stimulated emission by reducing instantaneous transverse gain.