An all-fiber source of pulsed twin beams at telecom band for quantum communication

TL;DR

This paper presents a simple, all-fiber pulsed twin beam source at 1550 nm for quantum communication, demonstrating noise reduction below shot noise limit, with potential for further improvements.

Contribution

First demonstration of an all-fiber pulsed twin beam source at telecom wavelength using a high gain fiber optical parametric amplifier.

Findings

Noise of intensity difference is 3.1 dB below shot noise limit.

After correction, noise reduction reaches 10.4 dB.

Identified factors limiting further noise reduction.

Abstract

Motivated by the pursuit of a simple system to produce non-classical light sources for long- distance quantum communication, we generate for the first time an all-fiber source of pulsed twin beams in 1550 nm band by using a high gain fiber optical parametric amplifier. The noise of intensity difference of the twin beams is below the shot noise limit by 3.1 dB (10.4 dB after correction for losses). A detailed study reveals a number of limiting factors for higher noise reduction. Therefore, further noise reduction will be feasible once care is taken for these limiting factors.