QUANTUM-NOISE REDUCTION IN A PARAMETRIC O SCILLATOR AND LASERS

Several systems have been implemented to date for the generation of sq ueezed light, i.e. light with quantum fluctuations reduced with respec t to the standard quantum limit or shot noise. Two kinds of systems ar e presented here : optical parametric oscillators and semiconductor la sers. Parametric conversion in crystals possessing a second order non- linearity has been the most efficient process to date to manipulate th e quantum fluctuations of light in various ways and reduce them. Semic onductor lasers can generate intensity squeezed light when they are dr iven with a regulated electrical pumping.