One of the most promising approach to ensure a secure communication is Quantum Key Distribution (QKD), a quantum cryptography method to produce and share encryption keys. Moreover, quantum internet can enable sending and receiving quantum bits (qubits) over a large network, paving the way to cloud quantum computing. Here, single photon detection is the key enabling technology.

Space-based Quantum Key Distribution (QKD) enables global secure communication by transmitting quantum states, like single photons, between satellites and ground stations. In Optical Ground Stations (OGS), SNSPDs are vital for their ultra-low dark counts, reducing detection noise, and low timing jitter, ensuring precise photon detection. These features enhance the efficiency and security of quantum key generation, making SNSPDs indispensable for Space QKD.

Quantum information leverages principles like superposition and entanglement to process, store, and transmit data, forming the foundation of quantum computing and communication. Superconducting nanowire single-photon detectors are crucial in these systems due to their high detection efficiency and ability to handle high photon rates, ensuring accurate and reliable measurements of quantum states critical for these technologies.

Deep space optical communication enables high-speed data transmission across vast distances, using laser-based systems for greater efficiency than traditional radio waves. This technology, tested in the Psyche mission in collaboration with ESA and NASA, showcases its potential for interplanetary data links. Superconducting nanowire single-photon detectors are integral to these systems, offering exceptional sensitivity and low noise, ensuring reliable signal reception even over extreme distances.

Photonics Quantum Computing relies on manipulating photons to perform quantum operations, offering scalability and room-temperature operation advantages. Photon-number-resolving (PNR) SNSPDs are crucial in this field, enabling precise measurement of photon states, which is essential for error correction and complex quantum algorithms.

LiDAR Measurements use laser pulses to map environments with high precision, critical for applications like autonomous navigation and environmental monitoring. Superconducting nanowire single-photon detectors enhance LiDAR performance with their high sensitivity and fast recovery times, enabling detection of faint reflections and operation over long distances.

Polarization-entangled photon sources and single-photon detectors are critical in many quantum applications. Here we demonstrate how to characterize such a source by coupling Single Quantum SNSPDs to Qunnect’s Qu-SRC.

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Photon number resolving (PNR) detectors canrecognize the number of arriving photons in one detection event. Until now, single-photon detectors based on superconducting nanowires (SNSPDs) could only resolve the photon number by making a multi-pixel array of SNSPDs connected to a read-out circuit that determine how many pixels click simultaneously.

However, the need for more pixels increases the cost of the system and the probability that multiple photons are absorbed in the same pixel, reducing the photon number information.

Single Quantum has recently improved the timing jitter and recovery time of SNSPDs. This allows for a less complicated solution for PNR: with only one SNSPD, the PNR can be measured through a simple jitter measurement.

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By pairing a superconducting nanowire single photon detector (SNSPD) with a Fourier transform spectrometer, a high-performance system with exceptional sensitivity and temporal resolution can be obtained.

With SNSPDs boasting >90% quantum efficiency in the near-infrared and up to 35% in the mid-infrared, this combination enables unprecedented sensitivity for time-resolved spectral measurements. Download the application note to explore how this system has been used by a research group at the University of Technology in Eindhoven, in collaboration with Nireos and PicoQuant, to study carrier dynamics in semiconductors and uncover new insights into photoluminescence spectra behavior.

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There are two types of oscilloscopes to measure radio frequency (RF) signals: Real-time and Sampling oscilloscopes. Typically, sampling oscilloscopes provide more electrical bandwidth, but they need a repetitive signal to analyze. Often sampling scopes are used to analyze optical signals.

In this application note, we showcase how a superconducting single-photon detector (SNSPD) can be used to analyze low-power optical signals together with a time tagger. In the present work, we characterize a 200 ps wide pulse from a fast pulse generator.

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Photon number resolving (PNR) detectors can recognize the number of arriving photons in one detection event.

Until now, single-photon detectors based on superconducting nanowires (SNSPDs) could only resolve the photon number by making a multi-pixel array of SNSPDs connected to a read-out circuit that determine how many pixels click simultaneously. However, the need for more pixels increases the cost of the system and still has the probability that multiple photons are absorbed in the same pixel, reducing the photon number information.

Single Quantum has improved the timing jitter and recovery time of SNSPDs. This allows for a less complicated solution for PNR: with only one SNSPD, the PNR can be measured through a simple jitter measurement.

Download the Application Note

Photon-correlation measurements are the backbone of quantum-optics experiments and are performed with dedicated hardware; a so-called “correlator”.

Under some circumstances, it would be beneficial to perform correlation measurements with an oscilloscope, because pulses and trigger levels can be visualized and the timing jitter is superior.

Typically, photon correlation experiments operate below 100 kCnts/s photons on each correlation channel. In this situation an RTO scope misses only a few percent of the incoming photons. In return a scope allows to perform the experiment in a What You See Is What You Get approach, making it easier to use than a traditional correlator.

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The field of brain imaging uses various techniques to image the structure and function of the nervous system. It is an emerging discipline crossing the boundary of medicine and neuroscience that has seen tremendous advances in recent years. 

The use of SNSPDs coupled to a confocal microscope operating in the SWIR opens up the possibility ofimaging biological structures 2 to 4 times deeper than previously possible with one-photon confocal fluorescence microscopy.

In this article, we show deep brain imaging achieved with infrared light while utilizing SNSPD’s.

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