Summary
An essential aspect of a quantum channel is the detection and analysis of quantum signals in the form of photons. For most free-space applications, the photons are polarization encoded, e.g. by assigning the ‘0’ to horizontally polarized photons and ‘1’ to vertically polarized photons. However, where the geometric reference is not constant at all times – such as links to hand-held devices or aircraft – polarization encoding leads to increased error. For these situations, time-bin encoding offers a promising robust solution. In this approach, time photon represents ‘0’ or ‘1’ depending on its detection in one of two time windows. Just like in the case of polarization encoding, where a photon can be in a superposition of vertical and horizontal polarization, a time-bin encoded photon can be in a superposition of being in the first and the second time window. Additionaly, quantum signals can be relatively easily converted between being polarization and time-bin encoded.
In this project, we jointly develop a quantum receiver with short time delay and high timing resolution that is optimized to handle time-bin encoded quantum signals. By combining our team’s expertise in free-space quantum receivers with a new detector array technology developed by Dr. Serge Charlebois and Jean-Francois Pratte of the University of Sherbrooke and by introducing new capabilities for integrated free-space time-bin encoding with high timing resolution detection, we expect to achieve state-of-the-art performance for quantum signal receiver technology. Such high-speed devices will open new doors for a variety of applications including daylight and continuous variable quantum key distribution, quantum sensing, imaging and LIDAR, and fundamental science tests.

Figure 1. The above animation shows the interference variation of the intensity on the single-photon camera. See details in (S. Sajeed et al, 2021)
Related Content

Magnetoelectric Coupling in New Composite Multiferroic Nanostructures as High-Density Quantum Multistate Memory Elements
Summary Magnetoelectric multiferroics are materials that exhibit correlated ferroelectric and ferromagnetic properties (i.e., a magnetoelectric effect). The resulting ability of these materials to simultaneously store data in electric polarization and magnetic moment could increase data storage density and data processing speed while reducing energy consumption. This project aims to design and fabricate new composite multiferroic […]
February 1, 2023

Micro-Supercapacitors Based on Termination Optimized MXene Quantum Dots with Ultra-High Rate Capability and Fast Frequency Response
Micro-supercapacitors (MCs) are miniaturized energy storage devices that can enhance the performance of wearable health devices, medical implants, wireless sensors, and micro-electromechanical systems due to their fast frequency response, long life cycle, and vast temperature operation. However, to make these MC systems into commercially feasible products, necessary improvements to current MC performance are necessary, primarily […]
June 12, 2023

Ultrafast Dynamical Studies of Valley-Based Qubits
Summary As monolayers, transition metal dichalcogenides (TMDCs) – such as tungsten diselenide (WSe2) – become direct-bandgap semiconductors capable of emitting light. Compared to conventional direct-bandgap semiconductors, such as III-V semiconductors like GaAs, excitons (quasiparticles made of an electron hole bound with an electron) and single-layer TMDCs (SL-TMDCs) have much stronger binding energy. Excitons and […]
June 29, 2018

Quantum Light Sources Based on Deterministic Photon Subtraction
Summary This project develops new sources of light that utilize quantum entanglement to enhance imaging resolution and detection. We aim to go beyond simple photon pairs and advance our understanding and control of new quantum states of light. Our approach uses deterministic single-photon subtraction (removing of a specific photon from a pulse of light) […]
July 13, 2018