Holographic capture of femtosecond pulse propagation

Abstract

We have implemented a holographic system to study the propagation of femtosecond laser pulses with high temporal ͑150 fs͒ and spatial resolutions ͑4 m͒. The phase information in the holograms allows us to reconstruct both positive and negative index changes due to the Kerr nonlinearity ͑positive͒ and plasma formation ͑negative͒, and to reconstruct three-dimensional structure. Dramatic differences were observed in the interaction of focused femtosecond pulses with air, water, and carbon disulfide. The air becomes ionized in the focal region, while in water long plasma filaments appear before the light reaches a tight focus. In contrast, in carbon disulfide the optical beam breaks up into multiple filaments but no plasma is measured. We explain these different propagation regimes in terms of the different nonlinear material properties.

Femtosecond filamentation in transparent media

“…In particular, two in phase filaments are found to fuse into a stable light channel. The simulation results by Xi et al (2006) are in keeping with experimental and numerical results by Méchain et al (2004b); Hosseini et al (2004a); Centurion et al (2005b). The fusion of filaments is driven by the constructive interference leading to an increase of the intensity in the overlapping region and to an enhancement of the Kerr refractive index, therefore attracting energy of the background reservoir toward the center.…”

“…In agreement with the scenario obtained for organizing multiple filaments, the interaction of conical emissions with the constellation generates additional filaments leading to a phase transition to a faster filamentation rate. By means of a holographic technique (Centurion et al, 2004) were able to capture laser induced plasma formation with 150 fs time resolution and to recover amplitude and phase information with 4 m spatial resolution, Centurion et al (2006) have shown that in carbon disulfide, a beam break-up into multiple filament occurs before the ionization intensity threshold is reached, in contrast with water and air where a fully ionized electron plasma was detected.…”

“…Using different diluted dyes, the filamentation dynamics was visualized through two-photon fluorescence. Several processes visible on Centurion et al (2005b) have monitored the formation of a large number of filaments by launching femtosecond laser pulses with powers much higher than the critical power for self-focusing in carbon disulfide. They have observed three stages for the filament formation: (i) the beam breaks up into a constellation, (ii) filaments form on the constellation.…”

Three-dimensional harmonic holographic microcopy using nanoparticles as probes for cell imaging

“…Moreover, the reference beam in holography can serve as a coherent local oscillator, leading to a gain in signal to noise ratio and a shot noise-limited performance of detection even at fast read-out [10]. As a pulsed holographic technique, the H 2 microscopy could reach a temporal resolution limited by the laser pulse width [10,36]. …”

Dynamics of strong-field laser-induced microplasma formation in noble gases

“…A considerable amount of research has focused on determining the electron concentration in fs laser-induced plasmas including interferometry [13,14], longitudinal diffractometry [15], in-line holographic imaging [16][17][18] electric conductivity [19,20] and shadowgraphic techniques. Shadowgraphic measurements are performed either by measuring the absorption of a probe laser as a consequence of inverse Bremsstrahlung [21] or the change in the refractive index gradient on a probe [22].…”