Single‐Photon Sources

Abstract

Photons' “light quantas” are considered as the central tool of the “second quantum revolution.” The “second quantum revolution” refers to the application of the discovered quantum mechanical laws toward the development of quantum information technologies that are aimed to completely outperform their classical counterparts. For practical applications, these emerging quantum technologies including all‐optical quantum information processing, communications, and metrology largely rely on the development of a novel optical tool – a bright, controllable, on‐demand source of single photons. Such a device is termed as a single‐photon source (SPS). In this article, we describe in detail the concept of a SPS and explore the various potential candidates in this regard.