Non classical states in interferometry
Giovanni De Cillis · 2008
We address the problem of phase and damping constant estimation in interferometry with non classical states of light. We investigate the behaviour of entangled Gaussian states of light in estimation of damping constants of dissipative media and we show how such entangled states can give, in principle, better estimation than the one in which single mode Gaussian states are employed for some values of the experimental parameters. We present a heuristic method to understand the tradeoff between roustness to loss of photons and precision in phase shift estimation. We also give a robust strategy, which exploits the known results of the quantum estimation theory (QET), for the estimation of the absolute value of the phase.