Adaptive Continuous Homodyne Phase Estimation Using Robust Fixed-Interval Smoothing

Abstract

Adaptive homodyne estimation of a continuously evolving optical phase using time-symmetric quantum smoothing has been demonstrated experimentally to provide superior accuracy in the phase estimate compared to adaptive or nonadaptive estimation using filtering alone. Here, we illustrate how the mean-square error in the adaptive phase estimate may be further reduced below the standard quantum limit for the stochastic noise process considered by using a Rauch-Tung-Striebel smoother as the estimator, alongwith an optimal Kalman filter in the feedback loop. Further, the estimation using smoothing can be made robust to uncertainties in the underlying parameters of the noise process modulating the system phase to be estimated. This has been done using a robust fixed-interval smoother designed for uncertain systems satisfying a certain integral quadratic constraint.

8 pages, 5 figures, Proceedings of the 2013 American Control Conference

References in corpus (5)

• A Quantum-Enhanced Prototype Gravitational-Wave Detector
• Time-Symmetric Quantum Theory of Smoothing
• Robust quantum parameter estimation: coherent magnetometry with feedback
• Quantum theory of optical temporal phase and instantaneous frequency. II. Continuous time limit and state-variable approach to phase-locked loop design
• Adaptive Continuous Homodyne Phase Estimation Using Robust Fixed-Interval Smoothing

Cited by in corpus (3)

• Adaptive Continuous Homodyne Phase Estimation Using Robust Fixed-Interval Smoothing
• Robust Smoothing for Estimating Optical Phase Varying as a Continuous Resonant Process
• Robust Estimation of Optical Phase Varying as a Continuous Resonant Process