Optimal amplitude quadrature control of an optical squeezer using an integral LQG approach

Squeezed states of light possess an asymmetric noise distribution whereby the uncertainty in one quadrature is less than the standard quantum noise limit. These states can be generated through a nonlinear optical process in an optical parametric oscillator (OPO). In this paper, we model such an optical squeezer and design an LQG controller which includes integral action to optimize the level of squeezing achieved in one of the quadratures of the fundamental optical field.