Nonlinear dynamics of high-power ultrashort laser pulses: exaflop computations on a laboratory station and subcycle light bullets
a International Laser Center of M.V. Lomonosov Moscow State University, Vorobevy gory, Moscow, 119992, Russian Federation
b International Center for Quantum Optics and Quantum Technologies (the Russian Quantum Center), ul. Novaya 100, Skolkovo, Moscow Region, 143025, Russian Federation
c Texas A&M University, College Station, Texas, USA
d National Research Centre ‘Kurchatov Institute’, pl. akad. Kurchatova 1, Moscow, 123182, Russian Federation
Propagation of high-power ultrashort light pulses involves an intricate nonlinear spatiotemporal dynamics where various spectral—temporal transformation effects are strongly coupled to the beam dynamics, which, in its turn, varies from the leading to the trailing edge of the pulse. Analysis of this nonlinear dynamics, accompanied by spatial instabilities, beam breakup into multiple filaments, and unique phenomena leading to the generation of extremely short optical field waveforms, is equivalent in its computational complexity to a simulation of time evolution of a billion-dimensional physical system. Such analysis requires exaflops of computational operations and is usually performed on high-performance supercomputers. Here, we present methods of physical modeling and numerical analysis that allow problems of this class to be solved on a laboratory computer boosted by a cluster of graphic accelerators. Exaflop computations performed with the use of these methods reveal new unique phenomena of spatiotemporal dynamics of high-power ultrashort laser pulses. We demonstrate that unprecedentedly short light bullets can be generated as a part of this dynamics, providing optical field localization both in space and time through a delicate balance of dispersion and nonlinearity with simultaneous suppression of diffraction-induced beam divergence due to the joint effect of Kerr and ionization nonlinearities.