The First Single-Photon Sources

Alain Aspect, Philippe Grangier

Steven Trpkovski, Lloyd C. L. Hollenberg, Steven Prawer

The nanodiamond technology has developed the first packaged, single-photon source that operates at room temperature and in well-lit environments, where an ideal single-photon source produces one photon per pulse. These sources are key components for building quantum information systems that can implement quantum-key distribution (QKD) for ultrasecure communications. The optically active color centers in diamond have been found to exhibit attractive optical properties through the nitrogen-vacancy (N-V) center emission ranging 600 to 750 nm, and that have realized the practical sources of single-photon emission. Photo statistics has to be determined to measure the performance of a single-photon source, which can be measured by the autocorrelation function g2 (0) using Hanbury-Brown and Twiss interferometer. The results showed that the SPS 1.01 demonstrates stable single-photon performance without requirement of recalibration.

Sana Khalid, Fabrice P. Laussy

We introduce the gapped coherent state in the form of a single-photon source (SPS) that consists of uncorrelated photons as a background, except that we demand that no two photons can be closer in time than a time gap [Formula: see text]. While no obvious quantum mechanism is yet identified to produce exactly such a photon stream, a numerical simulation is easily achieved by first generating an uncorrelated (Poissonian) signal and then for each photon in the list, either adding such a time gap or removing all photons that are closer in time from each other than [Formula: see text]. We study the statistical properties of such a hypothetical signal, which exhibits counter-intuitive features. This provides a neat and natural connection between continuous-wave (stationary) and pulsed single-photon sources, with also a bearing on what it means for such sources to be perfect in terms of single-photon emission.

Matthew T. Rakher

Moez Attia, Amor Gueddana, Rihab Chatta

In this work we address a comparison study between two kinds of Single Photon Sources (SPS). The first SPS is an Enhanced SPS (ESPS), which consists of an association between InAs/GaAs Quantum Dot (QD) and photonic crystal (PC) microcavity. The ESPS emits a single photon at 1550 nm with probability P1 around 0.7. The second SPS is the Heralded SPS (HSPS) and based on active two-dimensional PC over LiNbO3 and emits photons at 1310 nm and 1550nm. The photon at 1310 nm triggers the detection mechanism of the photon at 1550nm. The probability to obtain a HSPS at 1550 nm is closed to 0.57. Finally, we present a comparison study between ESPS and HSPS when they are used in an application of quantum communication.