Simulation of white light generation and near light bullets using a novel numerical technique

- Accurate 3+1D simulation for nonlinear propagation of optical ultrafast pulses in bulk material. Relies on a new numerical technique: First of its kind simulation.
- Simulation models a derivative nonlinear Schröedinger equation. Models a hard to study nonlinear optical effect: Self-steepening.
- The physical effects can directly be seen in an intuitive way from method.
- Models in detail an optical light bullet that emerges in the experiment being studied. Comparison to experimental results yields good fit.
- A new adaptive step size algorithm is tailor made for this optical simulation and presented in appendix.

An accurate and efficient simulation has been devised, employing a new numerical technique to simulate the derivative generalised non-linear Schrödinger 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 3.1 µm 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.