Bandwidth enhancement for parametric amplifiers operated in chirped multi-beam mode

TL;DR

This paper explores bandwidth enhancement in multi-beam OPCPA systems using DKDP amplifiers, achieving up to 50% increase through spectral filtering and phase manipulation techniques.

Contribution

It introduces novel configurations for bandwidth enhancement in multi-beam OPCPA, including near broadband limit operation and spectral filtering strategies.

Findings

Bandwidth up to 50% increased

Effective recombination via spectral filtering

Optimization independent of non-collinear OPCPA recipes

Abstract

In this paper we discuss the bandwidth enhancement that can be achieved in multi-Joule optical parametric chirped pulse amplification (OPCPA) systems exploiting the tunability of parametric amplification. In particular, we consider a pair of single pass amplifiers based on potassium dideuterium phosphate (DKDP), pumped by the second harmonic of Nd:glass and tuned to amplify adjacent regions of the signal spectrum. We demonstrate that a bandwidth enhancement up to 50% is possible in two configurations; in the first case, one of the two amplifiers is operated near its non-collinear broadband limit; to allow for effective recombination and recompression of the outgoing signals this configuration requires filtering and phase manipulation of the spectral tail of the amplified pulses. In the second case, effective recombination can be achieved simply by spectral filtering: in this configuration, the optimization of the parameters of the amplifiers (pulse, crystal orientation and crystal length) does not follow the recipes of non-collinear OPCPA.