Quantum noise in optical interferometers

TL;DR

This paper investigates quantum noise in optical interferometers for gravitational wave detection, analyzing whether signal amplification can occur without increasing photon counting noise through squeezed vacuum injection.

Contribution

It demonstrates that amplification without noise increase is not feasible with reasonable squeezing, providing detailed photon distribution calculations for different parameters.

Findings

Amplification without noise increase is not possible at reasonable squeezing levels.

Photon distributions vary with beam splitter angles and squeezing parameters.

Injected squeezed vacuum affects photon counting noise and signal amplification.

Abstract

We study the photon counting noise in optical interferometers used for gravitational wave detection. In order to reduce quantum noise a squeezed vacuum is injected into the usually unused input port. It is investigated under which conditions the gravitational wave signal may be amplified without increasing counting noise concurrently. Such a possibility was suggested as a consequence of the entanglement of the two output ports of a beam splitter. We find that amplification without concurrent increase of noise is not possible for reasonable squeezing parameters. Photon distributions for various beam splitter angles and squeezing parameters are calculated.