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

J. Ahrens,B. Schulz,O. Prochnow,T. Binhammer,T. Lang,M. Frede,U. Morgner

doi:10.1364/oe.24.008074

J. Ahrens, B. Schulz + Show 5 more

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https://doi.org/10.1364/oe.24.008074

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Abstract

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.

Highlights

The variety of Optical Parametric Chirped Pulse Amplification (OPCPA) systems [1] is increasing quickly due to the huge potential and variability of this concept to reach ultrashort laser pulses with high energies at high repetition rates ranging over a wide range of wavelength regimes from the visible to the mid-infrared [2]
We present a compact few-cycle 100 kHz OPCPA system pumped by a CPA-free picosecond Nd:YVO4 solid-state amplifier with alloptical synchronization to an ultra-broadband Ti:sapphire oscillator
Efficient parametric amplification was realized by a two stage double-pass scheme with following chirped mirror compressor

Summary

Introduction

The variety of Optical Parametric Chirped Pulse Amplification (OPCPA) systems [1] is increasing quickly due to the huge potential and variability of this concept to reach ultrashort laser pulses with high energies at high repetition rates ranging over a wide range of wavelength regimes from the visible to the mid-infrared [2]. Partial use of a pump pulse in the parametric amplification stages with several subsequent crystals was investigated theoretical [7] and realized experimentally with a rather complicated setup at 10 Hz repetition rate with 8 ns pump using the so called time-shear power amplification based on three nonlinear crystals [8] This system includes a bulk grating stretcher to reach stretched pulse durations in the ns-range as well as a grating compressor for recompression. We present for the first time to our knowledge a simple sequential pump depletion approach for 10 ps pumped OPA stages at high repetition rate (>100 kHz) which avoids excessive chirping of the signal pulses by partial pump depletion in a simple double-pass configuration For this configuration no additional nonlinear crystal and only two curved mirrors are necessary. Pulse compression of the broadband spectrum was realised by the use of double-chirped-mirror (DCM) pairs [19]

Parametric amplification results

Conclusion