Normal impact of a ball rotating around its linear velocity.

We report on an experimental study of the normal impact on a solid surface of a table tennis ball that rotates around its linear velocity vector. We observe that the ratio of the reflected velocity to the incident velocity does not depend on the initial spin. In contrast, the reflected spin depends not only on the incident spin but also on the incident velocity.

Oblique impact of a buckling table-tennis ball on a rigid surface.

We report on the rebound of a table-tennis ball impinging without any initial spin in oblique incidence on a rigid surface. We show that, below a critical incidence angle, the ball rolls without sliding when bouncing back from the surface. In that case, the reflected angular velocity acquired by the ball can be predicted without any knowledge of the properties of the contact between the ball and the solid surface.

Dynamical buckling of a table-tennis ball impinging normally on a rigid target: Experimental and numerical studies.

We report on the dynamical buckling of a spherical shell (a table-tennis ball) impinging in normal incidence on a rigid surface (a glass plate). Experimentally, we observe and decipher the geometrical characteristics of the shell profile in the contact region along with global metrics such as the contact duration and the coefficient of restitution of the linear velocity. We determine, in particular, the onset of the ball buckling instability.

Thermal noise of a cryocooled silicon cantilever locally heated up to its melting point.

The Fluctuation-Dissipation Theorem (FDT) is a powerful tool to estimate the thermal noise of physical systems in equilibrium. In general, however, thermal equilibrium is an approximation or cannot be assumed at all. A more general formulation of the FDT is then needed to describe the behavior of the fluctuations.

Large and extremely low loss: the unique challenges of gravitational wave mirrors.

This paper describes the making of large mirrors for laser interferometer gravitational wave detectors. These optics, working in the near infrared, are among the best optics ever created and played a crucial role in the first direct detection of gravitational waves from black holes or neutron star fusions.

A gated quantum dot strongly coupled to an optical microcavity.

The strong-coupling regime of cavity quantum electrodynamics (QED) represents the light-matter interaction at the fully quantum level. Adding a single photon shifts the resonance frequencies-a profound nonlinearity. Cavity QED is a test bed for quantum optics and the basis of photon-photon and atom-atom entangling gates.

Hydrodynamics control shear-induced pattern formation in attractive suspensions.

Dilute suspensions of repulsive particles exhibit a Newtonian response to flow that can be accurately predicted by the particle volume fraction and the viscosity of the suspending fluid. However, such a description fails when the particles are weakly attractive. In a simple shear flow, suspensions of attractive particles exhibit complex, anisotropic microstructures and flow instabilities that are poorly understood and plague industrial processes.

A new method of probing mechanical losses of coatings at cryogenic temperatures.

A new method of probing mechanical losses and comparing the corresponding deposition processes of metallic and dielectric coatings in 1-100 MHz frequency range and cryogenic temperatures is presented. The method is based on the use of high-quality quartz acoustic cavities whose internal losses are orders of magnitude lower than any available coating nowadays. The approach is demonstrated for chromium, chromium/gold, and multilayer tantala/silica coatings.