Taming chaos: 16 mJ picosecond Ho:YLF regenerative amplifier with 0.7 kHz repetition rate

Abstract

Nonlinear dynamics of continuous-wave pumped regenerative amplifiers operating at 2 μm are investigated. At repetition rates near 1 kHz, three different operation regimes are observed, including stable regular, chaotic, and subharmonic dynamics. Numerical simulations reproduce this behavior in a quantitative way. In particular, we find stable periodic doubling regimes in which every other seed pulse experiences high gain. Exploiting a narrow parameter window beyond the onset of chaos enables operation of a high-gain picosecond Ho:YLF regenerative amplifier which delivers up to 16 mJ picosecond pulses at 2050 nm. Energy fluctuations of the 700 Hz pulse train are as low as 0.9% rms.

Millijoule femtosecond pulses at 1937 nm from a diode-pumped ring cavity Tm:YAP regenerative amplifier

“…The spectrum is basically the same as the 1 kHz repetition rate case, which means that no serious nonlinear effect exists in the laser system at this energy level. Bifurcation effect can occur at repetition rates close to the inverse of the upper state lifetime [21,[32][33][34][35]. It is not observed here for neither 500 Hz nor 1 kHz.…”

High-repetition-rate and high-power picosecond regenerative amplifier based on a single bulk Nd:GdVO4 crystal

“…or working in a bistable regime with a negligible lower bifurcation branch [23] . Consequently, efforts to optimize system parameters are necessary to achieve stable and efficient performance.…”

Millijoule-level, kilohertz-rate, CPA-free linear amplifier for 2 μm ultrashort laser pulses

“…In Ref. [14], the pump and amplification phases are calculated sequentially. The inverted fraction is iterated along the propagation axis of the gain medium with a fixed pump and laser mode diameter.…”