Jan Ahrens

500 kHz OPCPA delivering tunable sub-20 fs pulses with 15 W average power based on an all-ytterbium laser

An optical parametric chirped pulse amplifier fully based on Yb lasers at 500 kHz is described. Passive optical-synchronization is achieved between a fiber laser-pumped white-light and a 515 nm pump produced with a 200 W picosecond Yb:YAG InnoSlab amplifier. An output power up to 19.7 W with long-term stability of 0.3% is demonstrated for wavelength tunable pulses between 680 nm and 900 nm and spectral stability of 0.2%; 16.5 W can be achieved with a bandwidth supporting 5.4 fs pulses. We demonstrate compression of 30 microjoule pulses to sub-20 fs duration with a prism compressor, suitable for high harmonic generation.An optical parametric chirped pulse amplifier fully based on Yb lasers at 500 kHz is described. Passive optical-synchronization is achieved between a fiber laser-pumped white-light and a 515 nm pump produced with a 200 W picosecond Yb:YAG InnoSlab amplifier. An output power up to 19.7 W with long-term stability of 0.3% is demonstrated for wavelength tunable pulses between 680 nm and 900 nm and spectral stability of 0.2%; 16.5 W can be achieved with a bandwidth supporting 5.4 fs pulses. We demonstrate compression of 30 µJ pulses to sub-20 fs duration with a prism compressor, suitable for high harmonic generation.

Multipass OPCPA system at 100 kHz pumped by a CPA-free solid-state amplifier.

We present a compact few-cycle 100 kHz OPCPA system pumped by a CPA-free picosecond Nd:YVO4 solid-state amplifier with all-optical synchronization to an ultra-broadband Ti:sapphire oscillator. This pump approach shows an exceptional conversion rate into the second harmonic of almost 78%. Efficient parametric amplification was realized by a two stage double-pass scheme with following chirped mirror compressor. The amount of superfluorescence was measured by an optical cross-correlation. Pulses with a duration of 8.7 fs at energies of 18 µJ are demonstrated. Due to the peak power of 1.26 GW, this simple OPCPA approach forms an ideal high repetition rate driving source for high-order harmonic generation.

Compact 200 kHz HHG source driven by a few-cycle OPCPA

We present a compact HHG source driven by a few-cycle, few μJ, 200 kHz OPCPA system. Efficient harmonics are generated from Neon, Argon and Krypton with conversion efficiency of 4.0×10⁻⁸, 1.2×10⁻⁶ and 4.1×10⁻⁶, respectively.

Parametric amplification of few-optical-cycle pulses

The reliable availability of energetic and very short pulses in the femtosecond regime triggered innumerable developments in research and application in physics, chemistry, and life sciences. Now, a new and superior technology reached maturity in research labs during the last decade, the few-cycle optical parametric chirped-pulse amplifier (OPCPA). The concept is advantageous against Ti:sapphire technology in many aspects, and enables few-cycle pulses with multi-kHz or MHz repetition rates. Furthermore, the technique can be up-scaled in average power due to the rapid development of Yb-based pump lasers (see Fig.1 ). This development paves the way to High Harmonic and tabletop XUV generation and new insights in physics and new fields of applications.

High power OPCPA system with adjustable repetition rate from 0.2 - 4 MHz

We present a few-cycle OPCPA system with μJ-level energy, which allows for an easy adaption of repetition rate over a wide range from 200 kHz - 4 MHz with high average output power of more than 2 W.

Ultrafast spectral switching of a Non-collinear Optical Parametric Oscillator (NOPO)

We present an ultrafast tunable non-collinear parametric oscillator which can be switched with >500 nm/ms over a wide spectral range from 650-1070 nm making the system ideally suited for novel ultrafast bio-imaging techniques.

Power and Energy Scaling of a Few-Cycle High Power OPCPA System with Adjustable Repetition Rate from 0.2 - 4 MHz

We present a compact, few-cycle OPCPA system with µJ-level energy, which allows an easy adaption of repetition rate over a wide range from 200 kHz - 4 MHz with high average output power of more than 2 W.

Few-Cycle and Phase Stable OPCPA Systems with High Repetition Rate

We present different approaches for high repetition rate, few-cycle pulse generation with μJ-level energy from compact OPCPA systems. The sources are based on octave spanning Ti:Sa oscillators with all-optical synchronization to state-of-the-art Ytterbium based amplifiers.

500 kHz OPCPA-Based UV-XUV Light Source For Time-Resolved Photoemission Spectroscopy

A 15 W, sub-20 fs OPCPA based on an Yb laser is used to demonstrate 6.3 eV fourth harmonic-based UV photoelectron spectroscopy with sub-60 fs time resolution and XUV high harmonic generation at 500 kHz.