Wide-beam simulation

In this wide-beam simulation, the initial condition is a Gaussian pulse with a phase perturbation. The waist of the initially collimated Gaussian was chosen to be 5 mm, the pulse duration is 500 fs, A = 248 nm, and the maximal intensity is 2 x 1014Wm-2. The total pulse energy is approximately 9mJ. A random phase perturbation is imposed on the pulse to initiate the transverse break-up of the pulse into multiple filaments (see Fig 13.3). We adjusted the amplitude of the perturbation such that it results in the filamentation onset after a few meters of propagation. 

This application of the z-UPPE simulator illustrates break-up of a high-power, wide femtosecond pulse into chaotically interacting light filaments. Beams that carry power exceeding the critical self-focusing power many times usually break transversally into multiple filaments. To capture such dynamics, a fully spatially resolved simulator is needed that doesn t impose axial symmetry. 

One limitation in simulation irradiation studies is represented by the fact that it is possible to obtain only fluxes of single, mono-energetic source often produced in a narrow unidirectional beam, while in space an organism is exposed to a flux of radiation vrith a wide spectrum of atomic mass and energy and from various directions. This prompted to test the biosensor in flights to the Earth stratosphere. ... 

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