A fiber-integrated single photon source emitting at telecom wavelengths

TL;DR

This paper introduces an alignment-free, fiber-integrated single photon source based on quantum dots emitting at telecom wavelengths, enabling efficient coupling for quantum communication applications.

Contribution

The work presents a novel, alignment-free fiber-integrated single photon source using a nanobeam with quantum dots and an adiabatic coupler, simplifying integration into quantum photonic systems.

Findings

Fiber-coupled single photon emission with 1.5% brightness

Photon purity achieved at 86%

Device enables integration into fiber-optic quantum circuits

Abstract

Fiber-coupled single photon sources are essential components of photonics-based quantum information processors. Most fiber-coupled single photon sources require careful alignment between fibers and quantum emitters. In this work, we present an alignment-free fiber-integrated single photon source based on an InAs/InP quantum dot emitting at telecom wavelengths. We designed a nanobeam containing the quantum dots attached to a fiber taper. The adiabatic tapered coupler of the nanobeam enables efficient light coupling to the fiber taper. Using a tungsten probe in a focused ion beam system, we transferred the nanobeam to the fiber taper. The observed fiber-coupled single photon emission occurs with a brightness of 1.5% and purity of 86%. This device provides a building block for fiber-optic quantum circuits that have various applications, such as quantum communication and distributed quantum computing.