Lorenz von Grafenstein

Non-steady-state enhancement cavities using pulse-dumping as power scaling concept of femtosecond lasers

We present a promising concept to reach femtosecond pulses with over 1 J energy at repetition rates of 15 kHz using a combination of fiber-amplifiers and ultra-long, non-steady-state enhancement-cavities. We show first preliminary results for a 10 MHz cavity.

High energy, kilohertz repetition rate laser system at 5 μm with multi-GW peak power

The generation of few-cycle millijoule pulses in the mid-wave infrared at a 1 kHz repetition rate is reported. Pulses at 5 μm with 75 fs duration and 14 GW peak power are produced via optical parametric chirped-pulse amplification.

Generation of few-cycle millijoule pulses at 5 μm employing a ZnGeP2-based OPCPA pumped with GW peak power pulses at 2 μm

A mid-infrared optical parametric chirped pulse amplification (OPCPA) system generating few-cycle pulses with multi-GW peak power at a 1 kHz repetition rate is presented. The system is pumped by a high-energy 2-μm picosecond source to exploit the high nonlinearity of ZnGeP2 (ZGP) crystals for parametric amplification. Employing a dispersion management scheme based on bulk materials and a spatial light modulator pulses as short as 75 fs are obtained in the idler at a center wavelength of 5 μm. The maximum generated pulse energy of 1.2 mJ translates into a peak power of 14 GW. Moreover, damage considerations of ZGP crystals at high 2 μm pump pulse intensities in the few-ten picosecond range are explored.

Millijoule 5 μm femtosecond OPCPA at 1 kHz repetition rate

Power-scalable ultrafast mid-IR coherent radiation plays an important role in strong field physics for driving nonlinear optical frequency conversion, such as high harmonic and x-ray generation. The most promising route to access the wavelength range >4 μm connected with scalability of the pulse energy relies on optical parametric chirped-pulse amplification (OPCPA) using non-oxide crystals, like ZGP or CSP [1]. A further key element is a high-performance pulsed 2-μm pump source. Using such 2-μm pump sources 100 fs pulses at 5.2 μm have been generated at 1 kHz with pulse energy of 80 μJ [2]. Recently, 180 fs pulses at 7 μm with energy of 200 μJ were demonstrated, however, operating at a rather low repetition rate of 100 Hz [1]. Here we present a 1 kHz ultrashort pulse OPCPA source delivering 1.3 mJ pulses at 5 μm with sub-200 fs duration.

High-energy femtosecond mid-IR OPCPA at kHz repetition rates

The generation of few-cycle pulses with multi-GW peak power in the mid-IR is reported. Pulses at 5 µm are produced via a 2-µm pumped OPCPA system at a 1 kHz repetition rate.

600 µJ, 5 µm, 1 kHz Femtosecond Optical Parametric Chirped Pulse Amplifier Pumped at 2 µm

A 1 kHz mid-IR OPCPA operating at 5 µm is presented. The 2-µm pumped ZnGeP2 parametric amplifiers deliver 600 µJ pulses with a compressed duration of 166 fs.

55 mJ Picosecond Ho:YLF Chirped Pulse Amplification System at 1 kHz Repetition Rate

A 2.051-µm CPA source based on a Ho:YLF amplifier chain generates 55 mJ picosecond pulses at a 1 kHz repetition rate. The system is distinguished by an excellent stability with a pulse-to-pulse rms <0.6%.

Compact High-brightness Hard X-ray Sources Driven by Femtosecond Mid-infrared Pulses

Interaction of intense mid-infrared pulses with metallic targets allows for the efficient generation of ultrashort hard x-ray pulses. Operation principles, source performance and recent progress towards mid-infrared drivers working at kilohertz repetition rates are presented. Article not available.

8 mJ, 1 kHz, Picosecond Ho:YLF Regenerative Amplifier

High-gain, continuous-wave pumped Ho:YLF regenerative amplifiers are reported, delivering up to 8 mJ picosecond pulses at 2050 nm, with energy fluctuations of the 1 kHz pulse train as low as 2% rms.