Physics Journal Club Meeting Butterfly effect in high

Physics Journal Club Meeting
Butterfly effect in high-power, ultrashort laser propagation
Rostislav Grynko
Department of Physics, Applied Physics and Astronomy,
Binghamton University
Modern pulsed-laser systems have dramatically reshaped our understanding of light and how it interacts with
matter. Commercially available Ti:Sapphire laser pulses with durations of a few femtoseconds (10 -15 s) routinely
deliver peak powers on the order of gigawatts and even higher. During propagation, a high power beam will
exhibit highly-nonlinear behavior: without the aid of a lens, it will self-focus until it reaches an intensity for
which any material can be ionized along its path, including air, giving rise to a column of plasma. This highintensity, self-guiding light structure is known as a filament, and it serves as an indispensable tool in many
applications, among which include lightning control, new light sources, and laser-based weapon technology.
In this presentation I will outline the physics of powerful laser beams in the context of filament
formation. In particular, I will discuss a process known as multi-filamentation, whereby a laser beam breaks up
into many parts. The phenomenon is highly stochastic, akin to the butterfly effect. Since their formation is
unpredictable, multiple filaments pose a series of problems to laser-based technology, so it is highly desirable to
develop a means by which the process can be controlled. In our experiments, we show that control and even
complete elimination of multi-filamentation can be achieved under proper focusing conditions. We develop a
highly versatile method to control beam breakup, and support our findings with a series of numerical
simulations. The high degree of control over nonlinearities that our results provide is supplemented with a series
of surprising physical insights which may be applicable to processes as seemingly unrelated as ocean waves.
Gaussian beam
Stochastic multiple filament formation
Friday, September 25, 2015
S2 Bldg. Room 138
Pizza @ Noon
Presentation @ 12:15
There will be a sign-in sheet for all attendees to sign.