Simulation of White Light Generation and Near Light Bullets Using a Novel Numerical Technique

TL;DR

This paper introduces a novel numerical simulation technique for modeling ultrafast optical pulse propagation, capturing complex effects like self-steepening and plasma, and revealing new physical phenomena relevant to white light generation.

Contribution

A new efficient numerical method for simulating the nonlinear Schrödinger equation in three dimensions, including effects like self-steepening and plasma, with validation against experimental data.

Findings

Identification of a stability point near the end of the crystal where a quasi-light bullet exists.

Observation of pulse collimation and temporal compression within the stable region.

Simulation reveals physical phenomena beyond experimental observations, aiding design of white light sources.

Abstract

An accurate and efficient simulation has been devised, employing a new numerical technique to simulate the derivative generalised non-linear Schr\"odinger equation in all three spatial dimensions and time. The simulation models all pertinent effects such as self-steepening and plasma for the non-linear propagation of ultrafast optical radiation in bulk material. Simulation results are compared to published experimental spectral data of an example ytterbium aluminum garnet system at 3.1um radiation and fits to within a factor of 5. The simulation shows that there is a stability point near the end of the 2 mm crystal where a quasi-light bullet (spatial temporal soliton) is present. Within this region, the pulse is collimated at a reduced diameter (factor of ~2) and there exists a near temporal soliton at the spatial center. The temporal intensity within this stable region is compressed by a factor of ~4 compared to the input. This study shows that the simulation highlights new physical phenomena based on the interplay of various linear, non-linear and plasma effects that go beyond the experiment and is thus integral to achieving accurate designs of white light generation systems for optical applications. An adaptive error reduction algorithm tailor made for this simulation will also be presented in appendix.