QUANTUM NONLINEAR OPTICS IN ARTIFICIALLY PHASE-MATCHED MATERIALS

We present a brief overview of the recent developments in quantum opti cs concerning the control and reduction of quantum noise. The achievem ents on squeezing, quantum non-demolition measurement and noiseless op tical functions are summarized. The present limitations in quantum per formance are discussed. We particularly stress the role of nonlinear o ptics and point out the advantages expected from the implementation of new artificially phase-matched materials, in different configurations including cascaded second-order nonlinearities.