22 research outputs found
Photon localization barrier can be overcome
In contradistinction to a widespread belief that the spatial localization of
photons is restricted by a power-law falloff of the photon energy density,
I.Bialynicki-Birula [Phys. Rev. Lett. 80, 5247 (1998)] has proved that any
stronger -- up to an almost exponential -- falloff is allowed. We are showing
that for certain specifically designed cylindrical one-photon states the
localization is even better in lateral directions. If the photon state is built
from the so-called focus wave mode, the falloff in the waist cross-section
plane turns out to be quadratically exponential (Gaussian) and such strong
localization persists in the course of propagation.Comment: Short communication -- 4 pages, 2 figure
Realization of laterally nondispersing ultrabroadband Airy pulses
We present the measurements of the spatiotemporal impulse response of a system creating nondispersing Airy pulses, i.e., ultrabroadband Airy beams whose main lobe size remains constant over propagation. A custom refractive element with a continuous surface profile was used to impose the cubic phase on the input beam. The impulse response of the Airy pulse generator was spatiotemporally characterized by applying a white-light spatial-spectral interferometry setup based on the SEA TADPOLE technique. The results were compared with the theoretical model and previously spatiotemporally characterized Airy pulses generated by a spatial light modulator. (C) 2014 Optical Society of Americ
Characterization of few-fs deep-UV dispersive waves by ultra-broadband transient-grating XFROG
Measuring the suppression of ultrashort pulses into Airy-Bessel light bullets with almost single-cycle temporal resolution
We have achieved ∼3 fs and ∼3 μm resolutions for full spatio-temporal characterization of impulse responses of optical systems using a white-light spectral interferometry set-up and demonstrate how a circular diffraction grating temporally focuses an Airy-Bessel wave-packet
Extremely broadband single-shot cross-correlation frequency-resolved optical gating using a transient grating as gate and dispersive element
Across-correlation frequency-resolved optical gating (FROG) concept, potentially suitable for characterizing few or sub-cycle pulses in a single shot, is described in which a counter-propagating transient grating is used as both the gate and the dispersive element in a FROG spectrometer. An all-reflective setup, which can operate over the whole transmission range of the nonlinear medium, within the sensitivity range of the matrix sensor, is also proposed, and proof-of-principle experiments for the ultraviolet and visible-to-near-infrared spectral ranges are reported. Published by AIP Publishing
Highly efficient four-wave parametric amplification in transparent bulk Kerr medium
We report on highly efficient four-wave optical parametric amplification in a water cell pumped by an elliptically shaped, ultrashort pulsed laser beam under non-collinear phase-matching configuration.
Energy conversion from pump to parametric waves as high as 25 % is
obtained owing to the achievement of 1-dimensional spatial-soliton regime, which guarantees high intensity over a large interaction length and ensures high beam quality