Power scaling of supercontinuum seeded megahertz-repetition rate optical parametric chirped pulse amplifiers.

Optical parametric chirped-pulse amplifiers with high average power are possible with novel high-power Yb:YAG amplifiers with kW-level output powers. We demonstrate a compact wavelength-tunable sub-30-fs amplifier with 11.4 W average power with 20.7% pump-to-signal conversion efficiency. For parametric amplification, a beta-barium borate crystal is pumped by a 140 W, 1 ps Yb:YAG InnoSlab amplifier at 3.25 MHz repetition rate. The broadband seed is generated via supercontinuum generation in a YAG crystal.

Yb:YAG Innoslab amplifier: efficient high repetition rate subpicosecond pumping system for optical parametric chirped pulse amplification.

We report on a Yb:YAG Innoslab laser amplifier system for generation of subpicsecond high energy pump pulses for optical parametric chirped pulse amplification (OPCPA) at high repetition rates. Pulse energies of up to 20 mJ (at 12.5 kHz) and repetition rates of up to 100 kHz were attained with pulse durations of 830 fs and average power in excess of 200 W. We further investigate the possibility to use subpicosecond pulses to derive a stable continuum in a YAG crystal for OPCPA seeding.

Compact diode-pumped 1.1 kW Yb:YAG Innoslab femtosecond amplifier.

We demonstrate a compact diode-pumped Yb:KGW femtosecond oscillator-Yb:YAG Innoslab amplifier master oscillator power amplifier (MOPA) with nearly transform-limited 636 fs pulses at 620 W average output power, 20 MHz repetition rate, and beam quality of M(x)(2) = 1.43 and M(y)(2) = 1.35. By cascading two amplifiers, we attain an average output power of 1.1 kW, a peak power of 80 MW, and a 615 fs pulse width in a single linearly polarized beam. The power-scalable MOPA is operated at room temperature, and no chirped-pulse amplification technique is used.

400W Yb:YAG Innoslab fs-Amplifier.

The Innoslab design, already established for neodymium doped laser crystals, was applied to ytterbium doped laser materials. Recent progresses in brightness of high power diode lasers facilitate efficient pumping of quasi-three-level laser materials. Innoslab amplifiers are compared to competing thin-disk and fiber fs-amplifiers. A compact diode-pumped Yb:YAG Innoslab fs-oscillator-amplifier system, scalable to the kilowatt range, was realized. Numerical simulations result in conditions for high efficiency and beam quality. Nearly transform and diffraction limited 680 fs pulses at 400 W average output power and 76 MHz repetition rate without using CPA technology have been achieved at room temperature so far.