Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission

Abstract

Self-assembled, epitaxially grown InAs/GaAs quantum dots (QDs) are promising semiconductor quantum emitters that can be integrated on a chip for a variety of photonic quantum information science applications. However, self-assembled growth results in an essentially random in-plane spatial distribution of QDs, presenting a challenge in creating devices that exploit the strong interaction of single QDs with highly confined optical modes. Here, we present a photoluminescence imaging approach for locating single QDs with respect to alignment features with an average position uncertainty <30 nm (<10 nm when using a solid-immersion lens), which represents an enabling technology for the creation of optimized single QD devices. To that end, we create QD single-photon sources, based on a circular Bragg grating geometry, that simultaneously exhibit high collection efficiency (48%±5% into a 0.4 numerical aperture lens, close to the theoretically predicted value of 50%), low multiphoton probability (g(2)(0) <1%), and a significant Purcell enhancement factor (≈3).

Metallic Nano-Rings for Efficient, Broadband Light Extraction from Solid-State Single-Photon Sources

“…A double light-emitting diode (LED) imaging technique is used to locate single QDs with nanometer-scale accuracy [5]. The emitters are then spectrally characterized by means of micro-photoluminescence laser spectroscopy at cryogenic temperatures.…”

Combined Atomic Force Microscopy and Photoluminescence Imaging to Increase the Yield of Quantum Dot Photonic Devices

“…We use photoluminescence imaging as a high-throughput technique to locate single QDs with nanometer scale accuracy [5][6][7] , by imaging their emission, along with reflected light off reference alignment marks, onto a sensitive CCD camera. A schematic of the sample and an example of a photoluminescence image of the QD emission and alignment marks are shown in Figs.…”

High-Quality Confinement of Visible Light in Disordered Photonic Crystal Waveguides in the Anderson-Localized Regime

“…We apply a nanoscale imaging technique [5] to directly image the confined optical modes, by illuminating the sample with a wide-area 455 nm LED, and imaging the emitted light with an electron multiplying charge coupled device (EMCCD) (Fig. 1b).…”