The conversion of phase to amplitude fluctuations of a light beam by an optical cavity

TL;DR

This paper presents a method using an optical cavity to convert phase fluctuations of a light beam into measurable intensity fluctuations, facilitating quantum information encoding and measurement.

Contribution

It introduces a novel technique employing an optical cavity to convert phase noise into intensity noise, enhancing quantum measurement capabilities.

Findings

Demonstrates conversion of phase to intensity fluctuations using an optical cavity

Analyzes quantum noise manipulation via resonance techniques

Compares the method to Pound-Drever-Hall and homodyne detection

Abstract

Very low intensity and phase fluctuations are present in a bright light field such as a laser beam. These subtle quantum fluctuations may be used to encode quantum information. Although intensity is easily measured with common photodetectors, accessing the phase information requires interference experiments. We introduce one such technique, the rotation of the noise ellipse of light, which employs an optical cavity to achieve the conversion of phase to intensity fluctuations. We describe the quantum noise of light and how it can be manipulated by employing an optical resonance technique and compare it to similar techniques, such as Pound-Drever-Hall laser stabilization and homodyne detection.