Abstract

The theoretical analysis of a feedback control system within an optical resonator have shown that the fluctuations of both the internal and the reflected lightfield can be suppressed below quantum noise limit^[1]. The control of the intensity of the field inside the resonator by manipulating the transmission of one of the cavity mirrors gives access to the individual quadratures of the internal field. This scheme does not require any optical process for the correlation of the noise sidebands. Consequently it is possible to control the degree of noise suppression and the quadrature of the squeezing externally. The limits of the noise suppression can be dervied directly from the theory while the spectrum of the noise is largely determined by the frequency response of the electronic feedback circuit.

© 1992 IQEC