On measurements of the canonical phase observable

TL;DR

This paper investigates how to measure the canonical phase observable in quantum optics, identifying minimal measurement models and proposing a method using double homodyne detection with state processing.

Contribution

It determines minimal measurement models for phase observables and introduces a method to measure the canonical phase distribution via double homodyne detection with state processing.

Findings

Minimal measurement models for phase observables identified

Canonical phase distribution can be measured with double homodyne detection

State processing via a two-mode unitary channel enables measurement

Abstract

Measurements of single-mode phase observables are studied in the spirit of the quantum theory of measurement. We determine the minimal measurement models of phase observables and consider methods of measuring such observables by using a double homodyne detector. We show that, in principle, the canonical phase distribution of the signal state can be measured via double homodyne detection by first processing the state using a two-mode unitary channel.