H∞ Filtering For An Optical Cavity System Disturbed By Lorentzian Quantum Noise

In this paper, we present a H ∞ filter for estimating dynamics of a Lorentzian-noise-disturbed non-Markovian cavity system with disturbances. The non-Markovian cavity system can be represented by an augmented system, where the Lorentzian quantum noise is parameterized by an ancillary system. This ancillary system is directly coupled to a principal system of interest and induces the non-Markovian dynamics of the principal system. The noise channels in this augmented model carry disturbances. To reduce the effect of the disturbances on the estimation, we design a H ∞ filter which can be obtained by solving a H ∞ control problem.