We study the effects of the quantum vacuum on the propagation of a Gaussian laser beam in vacuum. By means of a double perturbative expansion in paraxiality and quantum vacuum terms, we provide analytical expressions for the self-induced transverse m
ode mixing, rotation of polarization, and third harmonic generarion. We discuss the possibility of searching for the self-induced, spatially dependent phase shift of a multipetawatt laser pulse, which may allow the testing of quantum electrodynamics and new physics models, such as Born-Infeld theory and models involving new minicharged or axion-like particles, in parametric regions that have not yet been explored in laboratory experiments.
We show that extreme vacuum pressures can be measured with current technology by detecting the photons produced by the relativistic Thomson scattering of ultra-intense laser light by the electrons of the medium. We compute the amount of radiation sca
ttered at different frequencies and angles and design strategies for the efficient measurement of pressure. In particular, we show that a single day experiment at a high repetition rate Petawatt laser facility such as VEGA, that will be operating in 2014 in Salamanca, will be sensitive, in principle, to pressures p as low as 10^{-16} Pa, and will be able to provide highly reliable measurements for p>10^{-14} Pa.
We show that an optical system involving competing higher-order Kerr nonlinearities can support the existence of ultrasolitons, namely extremely localized modes that only appear above a certain threshold for the central intensity. Such new solitary w
aves can be produced for powers below the usual collapse threshold, but they can also coexist with ordinary, lower-intensity solitons. We derive analytical conditions for the occurrence of multistability and analyze the dynamics of the different kinds of fundamental eigenmodes that can be excited in these nonlinear systems. We also discuss the possible transitions between solitary waves belonging to different nonlinear regimes through the mechanism of soliton switching.
Recent experiments have proved that the response to short laser pulses of common optical media, such as air or Oxygen, can be described by focusing Kerr and higher order nonlinearities of alternating signs. Such media support the propagation of stead
y solitary waves. We argue by both numerical and analytical computations that the low power fundamental bright solitons satisfy an equation of state which is similar to that of a degenerate gas of fermions at zero temperature. Considering in particular the propagation in both $O_2$ and air, we also find that the high power solutions behave like droplets of ordinary liquids. We then show how a grid of the fermionic light bubbles can be generated and forced to merge in a liquid droplet. This leads us to propose a set of experiments aimed at the production of both the fermionic and liquid phases of light, and at the demonstration of the transition from the former to the latter.
We analyze both theoretically and by means of numerical simulations the phenomena of filamentation and dynamical formation of self-guided nonlinear waves in media featuring competing cubic and quintic nonlinearities. We provide a theoretical descript
ion of recent experiments in terms of a linear stability analysis supported with simulations, showing the possibility of experimental observation of the modulational instability suppression of intense light pulses travelling across such nonlinear media. We also show a novel mechanism of indirect excitation of {em light condensates} by means of coalescence processes of nonlinear coherent structures produced by managed filamentation of high power laser beams.
We show that a laser beam which propagates through an optical medium with Kerr (focusing) and higher order (defocusing) nonlinearities displays pressure and surface-tension properties yielding capillarity and dripping effects totally analogous to usu
al liquid droplets. The system is reinterpreted in terms of a thermodynamic grand potential, allowing for the computation of the pressure and surface tension beyond the usual hydrodynamical approach based on Madelung transformation and the analogy with the Euler equation. We then show both analytically and numerically that the stationary soliton states of such a light system satisfy the Young-Laplace equation, and that the dynamical evolution through a capillary is described by the same law that governs the growth of droplets in an ordinary liquid system.
