# Emission of photon pairs in optical fiber -- effect of zero-point fluctuations

## TL;DR

This paper investigates photon pair emission in optical fibers caused by zero-point fluctuations and periodic optical length changes, proposing a nonperturbative model predicting enhanced radiation suitable for entangled photon sources.

## Contribution

It introduces a nonperturbative theoretical framework for photon pair emission in fibers due to zero-point fluctuations and optical length oscillations, highlighting conditions for strong radiation peaks.

## Key findings

- Strong radiation peak when oscillation amplitude matches half the laser wavelength
- Enhanced photon emission in long fibers due to periodic length changes
- Potential application as a source of entangled photons

## Abstract

A nonlinear quantum-optical process is considered: emission of photon pairs by the reflecting end of a fiber excited by a standing laser wave. Radiation occurs due to periodic changes in the optical length of the fiber over time. This radiation can be significantly enhanced in long fibers. Because of this enhancement, a nonperturbative description of the process is required. Such a description presented here predicts a strong peak of radiation, if the amplitude of the oscillations of the optical length coincides with half of the laser wavelength. The considered phenomenon can be used to create a source of entangled photons.

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Source: https://tomesphere.com/paper/1907.04321