Suppression of Kerr-Induced Satellites in Multi-Pulse CPA

TL;DR

This paper investigates the limitations of multi-pulse chirped pulse amplification in the THz regime caused by Kerr nonlinearity and proposes practical methods to suppress distortions and enhance energy scaling.

Contribution

It provides experimental and numerical analysis of Kerr-induced distortions in THz burst-mode CPA and introduces optimization strategies to suppress nonlinear effects.

Findings

Suppression of Kerr-induced satellites improves burst fidelity.

Optimized burst parameters reduce spectral and temporal distortions.

Modulation techniques effectively mitigate nonlinear phase shifts.

Abstract

Amplification of bursts of ultrashort pulses is very challenging when the intraburst repetition frequency reaches the THz range, corresponding to (sub)-ps intervals between consecutive pulses. Periodic interference significantly modifies conditions for chirped pulse amplification (CPA) which gives rise to temporal and spectral distortions during CPA due to the optical Kerr nonlinearity. Multi-pulse chirped amplification to mJ energies may lead to a pronounced degradation of burst fidelity and the appearance of periodic temporal satellites after de-chirping the amplified waveform. We study, experimentally and numerically, the limitations of THz burst-mode CPA caused by self- and cross-phase modulation. A number of practical recipes to suppress nonlinear distortions and improve energy scaling by optimizing burst parameters and applying modulation techniques are presented.