Search results for "Physics::Optics"
showing 10 items of 1958 documents
Controlled insertion and retrieval of atoms coupled to a high-finesse optical resonator
2008
We experimentally investigate the interaction between one and two atoms and the field of a high-finesse optical resonator. Laser-cooled caesium atoms are transported into the cavity using an optical dipole trap. We monitor the interaction dynamics of a single atom strongly coupled to the resonator mode for several hundred milliseconds by observing the cavity transmission. Moreover, we investigate the position-dependent coupling of one and two atoms by shuttling them through the cavity mode. We demonstrate an alternative method, which suppresses heating effects, to analyze the atom-field interaction by retrieving the atom from the cavity and by measuring its final state.
Robust creation of atomic W state in a cavity by adiabatic passage
2009
We propose two robust schemes to generate controllable (deterministic) atomic W-states of three three-level atoms interacting with an optical cavity and a laser beam. Losses due to atomic spontaneous emissions and to cavity decay are efficiently suppressed by employing adiabatic passage technique and appropriately designed atom-field couplings. In these schemes the three atoms traverse the cavity-mode and the laser beam and become entangled in the free space outside the cavity.
Dynamics of thermally induced optical nonlinearity in GaSe thin slabs
1996
A study of the nonlinear effects shown by thin slabs of GaSe metaled with Au is presented.
Recent advances in the development of holey optical fibers based on sulfide glasses
2006
International audience; Microstructured optical fibers as new optical objects have been developed in the recent past years, firstly from silica glass and then from other oxide glasses such as tellurite or different heavy cations oxide glasses. However very few results have been reported concerning non-oxide glasses and more particularly chalcogenide glasses. In a photonic crystal fiber the arrangement of air holes along the transverse section of the fiber around a solid glassy core leads to unique optical properties, such as for example broadband single-mode guidance, adjustable dispersion, nonlinear properties. Since the effective modal area is adjustable thanks to geometrical parameters, …
Effects of water dielectric saturation on the space–charge junction of a fixed-charge bipolar membrane
2000
Abstract The dielectric saturation at the space–charge junction of a fixed-charge bipolar membrane is studied using the theoretical approach by Booth for the water dielectric constant and the Poisson equation for the electrical double layer at the junction. The numerical solution gives the electric field and dielectric constant profiles through the junction as well as the junction thickness as a function of the voltage drop. The water dielectric constant decreases substantially for the large electric fields that may occur at the narrow bipolar junction.
Observing the anisotropic optical response of the heavy-fermion compound UNi2 Al3
2010
The optical conductivity of heavy fermions can reveal fundamental properties of the charge carrier dynamics in these strongly correlated electron systems. Here we extend the conventional techniques of infrared optics on heavy fermions by measuring the transmission and phase shift of THz radiation that passes through a thin film of UNi 2 Al 3 , a material with hexagonal crystal structure. We deduce the optical conductivity in a previously not accessible frequency range, and furthermore we resolve the anisotropy of the optical response (parallel and perpendicular to the hexagonal planes). At frequencies around 7 cm -1 , we find a strongly temperature-dependent and anisotropic optical conducti…
Experimental generation of optical flaticon pulses
2013
International audience; We experimentally investigate the nonlinear reshaping of a continuous wave which leads to chirp-free and flat-top intense pulses or flaticons exhibiting strong temporal oscillations at their edges and a stable self-similar expansion upon propagation of their central region. This study was performed in the normal dispersion regime of a non-zero dispersion-shifted fiber and involved a sinusoidal phase modulation of the continuous wave. Our fiber optics experiment is analogous to considering the collision between oppositely directed currents near the beach, and it may open the way to new investigations in the field of hydrodynamics.
Fast Response Vibration Sensor Based on Bragg Gratings Written on Tapered Core Fibers
2006
Bragg gratings written in tapered core fibers are used to measure mechanical vibrations with a time response better than 10 μs. The system is compact, low-cost and can be wavelength multiplexed.
Interference-assisted detection of dark photon using atomic transitions
2019
Dark photon is a massive vector particle which couples to the physical photon through the kinetic mixing term. Such particles, if exist, are produced in photon beams and, in particular, in laser radiation. Due to the oscillations between the physical photon and the dark photon, the latter may be, in principle, detected in the light-shining-through-a-wall experiment. We propose a variant of this experiment where the detection of dark photons is based on the atomic transitions. The key feature of this scheme is that the detection probability is first order in the coupling constant due to the interference term in the photon and dark photon absorption amplitudes. We expect that such experiment …
Frequency conversion of propagating surface plasmon polaritons by organic molecules
2008
We demonstrate frequency conversion of surface plasmon polaritons (SPP) by utilizing the coupling between organic dye molecules and SPP. Launching of SPPs into a plasmonic waveguide is done in two ways: by optically excited molecules and by quantum dots (QDs). QDs are demonstrated to overcome the major problem of bleaching occurring with molecules. The SPP propagates tens of micrometers and clear frequency conversion is observed in the SPP spectrum after passing an area of converter molecules. The use of molecules and QDs as elements of all-plasmonic devices has the potential for high integration and use of self-assembly in fabrication. Peer reviewed