Related papers: Observation of Optomechanical Strain in a Cold Ato…
We have demonstrated an atom-optical lens, with the advantage of a small scale and flexible adjustment of the parameters, realized by a far red-detuned Gaussian laser beam perpendicular to the propagation direction of the cold atomic cloud.…
Cold atomic clouds constitute highly resonant nonlinear optical media, whose refractive index can be easily tuned via the light frequency. When subjected to a retro-reflected laser beam and under appropriate conditions, the cloud undergoes…
The rapidly developing field of optomechanics aims at the combined control of optical and mechanical (solid-state or atomic) modes. In particular, laser cooled atoms have been used to exploit optomechanical coupling for self-organization in…
Cooperative scattering of light by an extended object such as an atomic ensemble or a dielectric sphere is fundamentally different from scattering from many point-like scatterers such as single atoms. Homogeneous distributions tend to…
We report a study on light force on a beam of neutral two-level atoms superimposed upon a few-cycle pulsed Gaussian laser field under both resonant and off-resonant condition. The phenomena of focusing, defocusing and steering of the…
We have realized a hybrid optomechanical system by coupling ultracold atoms to a micromechanical membrane. The atoms are trapped in an optical lattice, which is formed by retro-reflection of a laser beam from the membrane surface. In this…
When a resonant laser sent on an optically thick cold atomic cloud is abruptly switched off, a coherent flash of light is emitted in the forward direction. This transient phenomenon is observed due to the highly resonant character of the…
We report on the atom optical manipulation of an atom laser beam. Reflection, focusing and its storage in a resonator are demonstrated. Precise and versatile mechanical control over an atom laser beam propagating in an inhomogeneous…
We investigate the deflection of light by a cold atomic cloud when the light-matter interaction is locally tuned via the Zeeman effect using magnetic field gradients. This "lighthouse" effect is strongest in the single-scattering regime,…
It is shown that homogeneous line-broadening in a diffuse cold atom cloud is proportional to the resonant optical depth of the cloud. Further, it is demonstrated how the strong directionality of the coherent interactions causes the cloud's…
We study the emergence of a collective optical response of a cold and dense $^{87}$Rb atomic cloud to a near-resonant low-intensity light when the atom number is gradually increased. Experimental observations are compared with microscopic…
The design of an experiment on the spontaneous crystallization of a laser-cooled, but thermal atomic cloud into a hexagonally structured phase is discussed. Atomic interaction is mediated by the dipole potential of an optical lattice formed…
We present an optical setup with focus-tunable lenses to dynamically control the waist and focus position of a laser beam, in which we transport a trapped ultracold cloud of 87-Rb over a distance of 28 cm. The scheme allows us to shift the…
The position response of a particle subjected to a perturbation is of general interest in physics. We study the modification of the position response function of an ensemble of cold atoms in a magneto-optical trap in the presence of tunable…
We experimentally and numerically study the temporal dynamics of light scattered by large clouds of cold atoms after the exciting laser is switched off in the low intensity (linear optics) regime. Radiation trapping due to multiple…
This communication describes the observation of a new type of dark spontaneous-force optical trap (dark SPOT) obtained without the use of a mask blocking the central part of the repumper laser beam. We observe that loading a magneto-optical…
We introduce a method for shaping a cold atom cloud using a vortex laser beam with a polarization singularity at its center, which creates a point of vanishing intensity. Exploiting this feature we experimentally demonstrate two different…
We present a theoretical analysis of a novel scheme for optical cooling of particles that does not in principle require a closed optical transition. A tightly confined laser beam interacting with a trapped particle experiences a phase…
We analyze a method of compressing a cloud of cold atoms by dynamic control of a far off resonance optical lattice. We show that by reducing the lattice spacing either continuously or in discrete steps while cooling the atoms with optical…
We report on light-shift tomography of a cloud of 87 Rb atoms in a far-detuned optical-dipole trap at 1565 nm. Our method is based on standard absorption imaging, but takes advantage of the strong light-shift of the excited state of the…