The Mean-field Approximation and Validity of a Truncated Bloch Hierarchy in Absorptive Bistability

Abstract

Absorptive bistability in a Fabry-Perot cavity is discussed in the framework of coupled field equations for forwards and backwards wave amplitudes. Recently proposed equations based on a truncated Bloch hierarchy are compared to equations derived without this truncation. The latter are valid throughout saturation where truncation of the Bloch hierarchy leads to inaccuracies. In this context the mean-field approximation for a Fabry-Perot is discussed. A new state equation is proposed as applicable to the Fabry-Perot case for weak absorption in a high Q cavity.