Squeezed quantum states in a bistable resonator

A quantum solution is suggested for the problem of the evolution of a field in a bistable ring resonator containing a nonlinear medium in which phase self-modulation or parametric amplification take place. A broad class of solutions valid for an arbitrary resonator Q factor is derived. It is shown that the known semiclassical descriptions of quantum state preparation in a resonator are inaccurate and in many cases yield incorrect results. For example, optimal suppression of the quantum fluctuations of one of the quadrature components of the field is achieved not at the lasing threshold but below it.