Eric Rosenthal

Energy Absorption in Femtosecond Filamentation

Energy deposition into air by laser filaments is spatially resolved along the propagation path. Single filaments formed under varied conditions were studied using longitudinal interferometry, sonographic probing, and photodiode energy-loss detection.

Spatial Phase Evolution of Filamenting Beams in Air

We resolve the spatial phase of a femtosecond beam filamenting in air throughout propagation. In contrast with recent simulations of filaments in water, air filaments do not exhibit a rapid accumulation of nonlinear phase.

Remote Collection of Optical Signals using Air Waveguides

Remote collection of weak distant signals significantly limits LIBS and LIDAR schemes. We demonstrate use of an air waveguide acting as a remote collection lens for increasing the signal-to-noise in such measurements.

Air waveguides generated by femtosecond filaments

Femtosecond filaments deposit energy in gases, producing a significant hydrodynamic response. We harness this effect to generate an optical waveguide in air with a millisecond lifetime and use it to guide a delayed laser pulse.

Terahertz energy scaling and saturation in two-color laser filamentation

We study broadband terahertz generation via two-color femtosecond laser filamentation with laser input energy up to 60 mJ. We find that the output THz energy strongly saturates due to ionization-induced laser defocusing in filamentation.

Tripling of plasma filament length by molecular quantum wakes in atmosphere

We tripled the length of the plasma filament from a single femtosecond pulse by injecting a second pulse into its molecular rotational quantum wake.

Temporal compression of ultrafast optical filaments by molecular quantum wakes in atmosphere

An ultrafast pulse filaments in atmosphere, leaving behind a molecular rotational quantum wake. A filamenting probe pulse is injected into the wake and is temporally compressed.