H∞ controller design for laser cavity squeezing in optomechanical sensors

In this paper, a controller is designed for robust stabilization of a quantum optics system subject to critical uncertainties and technical limitations such as laser noise and detector imprecision. This problem is formulated in the framework of robust H_∞ control design. A Coherent feedback quantum control is developed by incorporating both shot noise and back- action noise. The output noise level is subsequently attenuated well below the shot noise level. The effectiveness of the proposed control strategy in squeezing the cavity output beam is demonstrated by simulation.