Integration of Colloidal PbS/CdS Quantum Dots with Plasmonic Antennas and Superconducting Detectors on a Silicon Nitride Photonic Platform

Single-photon sources and detectors are indispensable building blocks for integrated quantum photonics, a research field that is seeing ever increasing interest for numerous applications. In this work, we implemented essential components for a quantum key distribution transceiver on a single photonic chip. Plasmonic antennas on top of silicon...

On-demand generation of background-free single photons from a solid-state source

True on-demand high-repetition-rate single-photon sources are highly sought after for quantum information processing applications. However, any coherently driven two-level quantum system suffers from a finite re-excitation probability under pulsed excitation, causing undesirable multi-photon emission. Here, we present a solid-state source of...

Polarization-insensitive fiber-coupled superconducting-nanowire single photon detector using a high-index dielectric capping layer

Superconducting-nanowire single photon detectors (SNSPDs) are able to reach near-unity detection efficiency in the infrared spectral range. However, due to the intrinsic asymmetry of nanowires, SNSPDs are usually very sensitive to the polarization of the incident radiation, their responsivity being maximum for light polarized parallel to the...

Universal fine-structure eraser for quantum dots

We analyze the degree of entanglement measurable from a quantum dot via the biexciton-exciton cascade as a function of the exciton fine-structure splitting and the detection time resolution. We show that the time-energy uncertainty relation provides means to measure a high entanglement even in presence of a finite fine-structure splitting...

Bright nanoscale source of deterministic entangled photon pairs violating Bell's inequality

Global, secure quantum channels will require efficient distribution of entangled photons. Long distance, low-loss interconnects can only be realized using photons as quantum information carriers. However, a quantum light source combining both high qubit fidelity and on-demand bright emission has proven elusive. Here, we show a bright photonic...

On-chip single photon filtering and multiplexing in hybrid quantum photonic circuits

Quantum light plays a pivotal role in modern science and future photonic applications. Since the advent of integrated quantum nanophotonics different material platforms based on III-V nanostructures-, colour centers-, and nonlinear waveguides as on-chip light sources have been investigated. Each platform has unique advantages and limitations;...

Overcoming power broadening of the quantum dot emission in a pure wurtzite nanowire

One of the key challenges in developing quantum networks is to generate single photons with high brightness, purity, and long temporal coherence. Semiconductor quantum dots potentially satisfy these requirements; however, due to imperfections in the surrounding material, the coherence generally degrades with increasing excitation power...

Deterministic Integration of Single Photon Sources in Silicon Based Photonic Circuits

A major step toward fully integrated quantum optics is the deterministic incorporation of high quality single photon sources in on-chip optical circuits. We show a novel hybrid approach in which preselected III-V single quantum dots in nanowires are transferred and integrated in silicon based photonic circuits. The quantum emitters maintain...

Design of broadband high-efficiency superconducting-nanowire single photon detectors

In this paper several designs to maximize the absorption efficiency of superconducting-nanowire single-photon detectors are investigated. Using a simple optical cavity consisting of a gold mirror and a SiO₂ layer, the absorption efficiency can be boosted to over 97%: this result is confirmed experimentally by the realization of an...

Photon pair generation in a silicon micro-ring resonator with reverse bias enhancement

Photon sources are fundamental components for any quantum photonic technology. The ability to generate high count-rate and low-noise correlated photon pairs via spontaneous parametric down-conversion using bulk crystals has been the cornerstone of modern quantum optics. However, future practical quantum technologies will require a scalable...

Single carbon nanotube photovoltaic device

Here we present photocurrent measurements on a single suspended carbon nanotube p-n junction. The p-n junction was induced by electrostatic doping by local gates, and the E11 and E22 resonances in the nanotube could be probed using photocurrent spectroscopy. Current-voltage characteristics were recorded, revealing an enhanced optoelectronic...

Read-out of superconducting single photon detectors

Detection arrangement having an array of at least one superconducting single photon detector (SSPD). The detection arrangement further has a cryogenic part (9) with the array of at least one SSPD (1), the cryogenic part (9) being at a superconducting temperature in operation. Also, a separate charge storage element (5) in the form of an...