N. Piovella

Slippage and superradiance in the high-gain FEL: Linear theory

Abstract We describe the linear regime of a Free-Electron-Laser Amplifier taking into account propagation effects (slippage). We demonstrate analytically, (for a simple case) the existence of two different solutions of the pulse propagation equations, which in suitable limits describe the Steady-State and the Superradiant regimes.

Quantum effects in the collective light scattering by coherent atomic recoil in a Bose–Einstein condensate

We extend the semiclassical model of the collective atomic recoil laser (CARL) to include the quantum mechanical description of the center-of-mass motion of the atoms in a Bose-Einstein condensate (BEC). We show that when the average atomic momentum is less than the recoil momentum

Controlled Dicke subradiance from a large cloud of two-level systems.

\hbar\vec q

Quantum theory of SASE FEL

, the CARL equations reduce to the Maxwell-Bloch equations for two momentum levels. In the conservative regime (no radiation losses), the quantum model depends on a single collective parameter,

Cooperativity in light scattering by cold atoms

\rho

Self-synchronization and dissipation-induced threshold in collective atomic recoil lasing

, that can be interpreted as the average number of photons scattered per atom in the classical limit. When

Observation of a Cooperative Radiation Force in the Presence of Disorder

\rho\gg 1

Superradiant light scattering and grating formation in cold atomic vapours

, the semiclassical CARL regime is recovered, with many momentum levels populated at saturation. On the contrary, when

Modification of radiation pressure due to cooperative scattering of light

\rho\le 1

Atom and photon measurement in cooperative scattering by cold atoms

, the average momentum oscillates between zero and