Lasy: an open-source library to initialize complex laser pulses in simulations of laser-plasma interactions*

Simulations of laser-plasma interactions often require the injection of complex laser pulses at the beginning of the simulation. This includes for instance non-Gaussian laser profiles inferred from experimental measurements, as well as lasers with involved spatio-temporal correlations such as flying-focus lasers.

Here we present lasy [1], an open-source Python library that allows users to easily describe various complex laser profiles. Using lasy, this laser profile can then be saved in a standardized openPMD [2] file, which can then be read by a number of Particle-In-Cell (PIC) codes, including WarpX, HiPACE++, and FBPIC. In addition, lasy supports different geometries (Cartesian, cylindrical) and has advanced utilities to, e.g., propagate the laser pulse out of focus, before starting the PIC simulation.

[1] https://github.com/LASY-org/lasy

[2] https://github.com/openPMD/openPMD-standard