Single quantum dots emit single photons at a time: Antibunching experiments

Abstract

We have studied the photoluminescence correlation from a single InAs/GaAs self-assembled Stranski–Krastanow quantum dot under continuous, as well as under pulsed excitation. Under weak continuous excitation, where the single dot luminescence is due primarily to single exciton recombinations, antibunching is observed in the single dot emission correlation. Under weak pulsed excitation, the number of photons emitted by the quantum dot per pulse is close to one. We present data obtained under both conditions and are able to show that devices based on single quantum dots can be used to generate single photons.

Photoneutralization and slow capture of carriers in quantum dots probed by resonant excitation spectroscopy

“…The results of 4 measurements (over a set of 12 measurements) are presented in figure 10. Even if the time window has a width of 350 ns, which is large for photon correlation experiments in InAs/GaAs QDs [14,47,48], it appears not large enough to observe the limit value of the number of coincidences at long time scales, and therefore, the data normalization becomes tricky. To overcome this problem, the raw experimental data are plotted in the unit of the number of coincidences as a function of the time delay τ .…”

Directed self‐assembly of single quantum dots for telecommunication wavelength optical devices

“…After relaxation, the quantum system is necessarily in its ground state, and can not emit until the next excitation pulse. Antibunched emission, a signature of single photon emission, has been observed in both the InAs/GaAs [10][11][12][13][14] and InAs/InP [15] material systems.…”

“…On demand emission is provided by pulsed excitation, the dwell time determined by the excitation used and the excitation recombination rate. It is the exciton recombination that has been used to demonstrate single photon emission in the InAs/GaAs material system using second-order correlation spectroscopy for both randomly nucleated [10,11,13,14] and site-controlled quantum dots [31,32]. Demonstration of single photon emission from InAs/InP quantum dots [15] has proved more difficult due to the inferior performance with respect to dark counts of single photon InGaAs detectors compared to Si CCD devices.…”

Dressed photon technology

“…The Au nanoparticle plays the role of improving the output effi ciency of propagating light serving as an output signal of the device. That is, since the gallium arsenide (GaAs) constituting the barrier layer has a large refractive index, optical signals emitted by the device are scattered backward in the direction of the substrate [19] . The Au nanoparticle shown in Figure 1 allows a greater portion of the scattered light to be released to the outside of the device.…”