7 research outputs found
Compensation of Beer-Lambert attenuation using non-diffracting Bessel beams
We report on a versatile method to compensate the linear attenuation in a
medium, independently of its microscopic origin. The method exploits
diffraction-limited Bessel beams and tailored on-axis intensity profiles which
are generated using a phase-only spatial light modulator. This technique for
compensating one of the most fundamental limiting processes in linear optics is
shown to be efficient for a wide range of experimental conditions (modifying
the refractive index and the attenuation coefficient). Finally, we explain how
this method can be advantageously exploited in applications ranging from
bio-imaging light sheet microscopy to quantum memories for future quantum
communication networks
Initiation à l'analyse spatiale à l'aide d'ArcView version 3.1
*INRA Centre de recherches de Nancy Laboratoire d'Intelligence Artificielle et Biométrie - 54280 Champenoux Diffusion du document : INRA Centre de recherches de Nancy Laboratoire d'Intelligence Artificielle et Biométrie - 54280 ChampenouxNational audienc
Blast waves in a paraxial fluid of light
We study experimentally blast wave dynamics on a weakly interacting fluid of
light. The fluid density and velocity are measured in 1D and 2D geometries.
Using a state equation arising from the analogy between optical propagation in
the paraxial approximation and the hydrodynamic Euler's equation, we access the
fluid hydrostatic and dynamic pressure. In the 2D configuration, we observe a
negative differential hydrostatic pressure after the fast expansion of a
localized over-density, which is a typical signature of a blast wave for
compressible gases. Our experimental results are compared to the Friedlander
waveform hydrodynamical model. Velocity measurements are presented in 1D and 2D
configurations and compared to the local speed of sound, to identify supersonic
region of the fluid. Our findings show an unprecedented control over
hydrodynamic quantities in a paraxial fluid of light
Agriculture et qualité de l'eau. Une approche interdisciplinaire de la pollution par les nitrates d'un bassin d'alimentation
National audienc
Analogue cosmological particle creation in an ultracold quantum fluid of light
In inflationary cosmology, the rapid expansion of the early universe resulted
in the spontaneous production of cosmological particles from vacuum
fluctuations, observable today in the cosmic microwave background anisotropies.
The analogue of cosmological particle creation in a quantum fluid could provide
insight, but an observation has not yet been achieved. Here we report the
spontaneous creation of analogue cosmological particles in the laboratory,
using a quenched 3-dimensional quantum fluid of light. We observe acoustic
peaks in the density power spectrum, in close quantitative agreement with the
quantum-field theoretical prediction. We find that the long-wavelength
particles provide a window to early times, and we apply this principle to the
cosmic microwave background. This work introduces a new quantum fluid, as cold
as an atomic Bose-Einstein condensate.Comment: 7 pages for the main text and 7 pages of supplementary materia
De la carte des Naudin à la carte IGN : précision et déformations spatiales de la feuille de Nancy
*INRA Centre de Nancy (FRA) Diffusion du document : INRA Centre de Nancy (FRA)National audienc