Compression of ultrashort laser pulses in planar hollow waveguides: a stability Analysis

C L Arnold,A Couairon,M Franco,A Mysyrowicz,S Akturk

doi:10.1364/oe.17.011122

Abstract

We investigate compression of ultrashort laser pulses by nonlinear propagation in gas-filled planar hollow waveguides, using (3+1)- dimensional numerical simulations. In this geometry, the laser beam is guided with a fixed size in one transverse dimension, generating significant spectral broadening, while it propagates freely in the other, allowing for energy up-scalability. In this respect the concept outperforms compression techniques based on hollow core fibers or filamentation. Small-scale self-focusing is a crucial consideration, which introduces mode deterioration and finally break-up in multiple filaments. The simulation results, which match well with initial experiments, provide important guidelines for scaling the few-cycle pulse generation to higher energies. Pulse compression down to few-cycle duration with energies up to 100 mJ levels should be possible.

Highlights

One of the main goals of today’s ultrafast nonlinear optics is the compression of ultrashort laser pulses down to the few-cycle regime
Near singlecycle pulses are commonly generated through nonlinear propagation in gas-filled hollow fibers [4] or through optical filamentation in noble gases [5, 6, 7, 8]
Due to potential damage to the fiber, the hollow fiber scheme supports pulse energies typically limited to sub-millijoules, in particular when driven at kHz-repetition rates

Summary

Introduction

One of the main goals of today’s ultrafast nonlinear optics is the compression of ultrashort laser pulses down to the few-cycle regime. Few-cycle pulses with higher energies (up to ∼100 mJ) are mainly generated through optical parametric chirped pulse amplification (OPCPA) [13, 14] These setups involve considerable experimental complexity and require the use of additional pump lasers. The theoretical work of Nurhuda et al [15] suggested a compression scheme using gas-filled planar hollow waveguides, which can address the issue of energy upscalability with significantly less experimental complexity. We present a comprehensive analysis of nonlinear propagation and pulse compression via planar hollow waveguides. We present the results of detailed (3+1)dimensional simulations of the spatio-temporal pulse dynamics in the waveguide, which provides understanding of the energy and compressibility limits of this technique, from which a practical criterion to reach the best pulse compression without compromising the spatial mode is established. The model is applied to define the conditions for the compression of very energetic pulses (>100 mJ) down to the few-cycle regime (

Numerical simulation results and experimental comparison

Analysis of the beam stability

Energy upscalability

Findings

Conclusion