Mutual information--based approach to adaptive homodyne detection of quantum optical states

Abstract

I propose an approach to adaptive homodyne detection of digitally modulated quantum optical pulses in which the phase of the local oscillator is chosen to maximize the average information gain, i.e., the mutual information, at each step of the measurement. I study the properties of this adaptive detection scheme by considering the problem of classical information content of ensembles of coherent states. Using simulations of quantum trajectories and visualizations of corresponding measurement operators, I show that the proposed measurement scheme adapts itself to the features of each ensemble. For all considered ensembles of coherent states, it consistently outperforms heterodyne detection and Wiseman's adaptive scheme for phase measurements [H.M. Wiseman, Phys. Rev. Lett. 75, 4587 (1995)].

Submutted to Phys. Rev. A

References in corpus (7)

• Quantum Cryptography
• The Quantum Jump Approach to Dissipative Dynamics in Quantum Optics
• Adaptive homodyne measurement of optical phase
• Quantum Trajectories and Quantum Measurement Theory
• Accessible information and optimal strategies for real symmetrical quantum sources
• Distinguishing between optical coherent states with imperfect detection
• Adaptive phase estimation is more accurate than non-adaptive phase estimation for continuous beams of light

Cited by in corpus (5)

• Discrimination of the binary coherent signal: Gaussian-operation limit and simple non-Gaussian near-optimal receivers
• Single-shot non-Gaussian Measurements for Optical Phase Estimation
• Adaptive homodyne phase discrimination and qubit measurement
• Optimal noisy quantum phase estimation with finite-dimensional states
• Optimal finite-dimensional probe states for quantum phase estimation