On‐chip single photon sources using planar photonic crystals and single quantum dots

Abstract

We review the basic light-matter interactions and optical properties of chip-based single photon sources, that are enabled by integrating single quantum dots with planar photonic crystals. A theoretical framework is presented that allows one to connect to a wide range of quantum light propagation effects in a physically intuitive and straightforward way. We focus on the important mechanisms of enhanced spontaneous emission, and efficient photon extraction, using all-integrated photonic crystal components including waveguides, cavities, quantum dots and output couplers. The limitations, challenges, and exciting prospects of developing on-chip quantum light sources using integrated photonic crystal structures are discussed.A sequence of optical pulses (top right) interacting with a single quantum dot embedded in a photonic crystal system, resulting in the emission of a train of single photons on-chip.

Atom–light interactions in photonic crystals

“…For example, the ability to tune band edges near atomic transition frequencies can give rise to strongly enhanced optical interactions [36][37][38][39][40] . This enables a single atom to exhibit nearly perfect emission into the guided modes (G 1D cG 0 ) and to act as a highly reflective mirror (for example, reflection |r 1 |\0.95 and transmission |t 1 |t0.05 for one atom 41 ).…”

Vertical-external-cavity surface-emitting lasers and quantum dot lasers

“…Their calculated results reproduce the features of the experimentally observed on-resonant spectral triplet, the origin of which has puzzled the community for several years. Such a formalism should prove to be useful for future studies, such as practical analyses of quantum information processing using QD spins and cavity QED [4,80,[85][86][87], as well as studies of the design and optimization of the performance of single photon sources [1,82,85]. We believe that these results above will stimulate a full understanding of the physical nature of solid-state cavity QED systems.…”

“…Recently, such a coupled system consisting of a nanocavity and a QD shown in Fig. 4(c) has been further extensively investigated because of its promising applications such as quantum information processing [4,[83][84][85][86], single photon sources [1,81,85], and ultimately low-threshold nanolasers [78,80,[86][87][88][89]. For such a single QD PhC nanocavity system, utilization of a single mode cavity with a sufficiently high Q factor as a lasing mode, the modal volume of which should be as small as possible to maximize the interaction with the single QD gain medium, is key to realize a thresholdless QD nanolaser.…”

“…These features are unique to semiconductor nanostructure systems and are not predicted by conventional cavity QED in atomic systems. In our study the QD was typically modeled by a simple atomic two-level system and the effect of pure dephasing was to broaden the transition energy of the two-level system [39,86], which makes it possible for the tail of the transition energy to overlap with the cavity energy, and generates an additional way in which to interact with the cavity. Owing to this interaction, a cavity photon is created with the transition of the excited two-level system to the ground state, a process generally known as the anti-Zeno effect (AZE), induced by pure dephasing in the QD.…”

Two-photon interference from a quantum dot microcavity: Persistent pure dephasing and suppression of time jitter

“…One of the most promising platforms for single-photon sources is solid-state quantum dots (QDs) [6][7][8][9][10]. Compared to alternative platforms, such as cold atoms or trapped ions, single QDs offer several advantages: they can be driven electrically, which is of crucial importance for compact future applications [11][12][13], and, in principle, can be integrated in complex photonic environments and architectures, such as on-chip quantum optical networks [14,15]. When embedded in a bulk semiconductor, however, QDs suffer from poor photon extraction efficiencies, since only a minor fraction of the photons can leave the high refractive index material.…”