207 research outputs found
Demonstration of a Thermally Coupled Row-Column SNSPD Imaging Array
While single-pixel superconducting nanowire single photon detectors (SNSPDs) have demonstrated remarkable efficiency and timing performance from the UV to near-IR, scaling these devices to large imaging arrays remains challenging. Here, we propose a new SNSPD multiplexing system using thermal coupling and detection correlations between two photosensitive layers of an array. Using this architecture with the channels of one layer oriented in rows and the second layer in columns, we demonstrate imaging capability in 16-pixel arrays with accurate spot tracking at the few-photon level. We also explore the performance trade-offs of orienting the top layer nanowires parallel and perpendicular to the bottom layer. The thermally coupled row-column scheme is readily able to scale to the kilopixel size with existing readout systems and, when combined with other multiplexing architectures, has the potential to enable megapixel scale SNSPD imaging arrays
Large array of low-frequency readout quantum capacitance detectors
Quantum capacitance detectors (QCDs) are photon shot noise-limited terahertz detectors based on a single Cooper-pair box superconducting qubit. The QCD has demonstrated photon shot noise-limited performance for 1.5 THz radiation under loading conditions between 10⁻²⁰ and 10⁻¹⁸ W and single-photon detection and counting at that frequency. We report here fabrication and preliminary characterization of a 441 pixel array of QCDs with readout frequencies between 700 and 850 MHz
Optically addressing single rare-earth ions in a nanophotonic cavity
We demonstrate optical probing of spectrally resolved single Nd rare-earth
ions in yttrium orthovanadate. The ions are coupled to a photonic crystal
resonator and show strong enhancement of the optical emission rate via the
Purcell effect, resulting in near radiatively limited single photon emission.
The measured high coupling cooperativity between a single photon and the ion
allows for the observation of coherent optical Rabi oscillations. This could
enable optically controlled spin qubits, quantum logic gates, and spin-photon
interfaces for future quantum networks
Time-walk and jitter correction in SNSPDs at high count rates
Superconducting nanowire single-photon detectors (SNSPDs) are a leading
detector type for time correlated single photon counting, especially in the
near-infrared. When operated at high count rates, SNSPDs exhibit increased
timing jitter caused by internal device properties and features of the RF
amplification chain. Variations in RF pulse height and shape lead to variations
in the latency of timing measurements. To compensate for this, we demonstrate a
calibration method that correlates delays in detection events with the time
elapsed between pulses. The increase in jitter at high rates can be largely
canceled in software by applying corrections derived from the calibration
process. We demonstrate our method with a single-pixel tungsten silicide SNSPD
and show it decreases high count rate jitter. The technique is especially
effective at removing a long tail that appears in the instrument response
function at high count rates. At a count rate of 11.4 MCounts/s we reduce the
full width at one percent maximum level (FW1%M) by 45%. The method therefore
enables certain quantum communication protocols that are rate-limited by the
(FW1%M) metric to operate almost twice as fast. \c{opyright} 2022. All rights
reserved.Comment: 5 pages, 3 figure
Waveguide-Coupled Superconducting Nanowire Single-Photon Detectors
We have demonstrated WSi-based superconducting nanowire single-photon detectors coupled to SiN_x waveguides with integrated ring resonators. This photonics platform enables the implementation of robust and efficient photon-counting detectors with fine spectral resolution near 1550 nm
Demonstration of a Thermally Coupled Row-Column SNSPD Imaging Array
While single-pixel superconducting nanowire single photon detectors (SNSPDs) have demonstrated remarkable efficiency and timing performance from the UV to near-IR, scaling these devices to large imaging arrays remains challenging. Here, we propose a new SNSPD multiplexing system using thermal coupling and detection correlations between two photosensitive layers of an array. Using this architecture with the channels of one layer oriented in rows and the second layer in columns, we demonstrate imaging capability in 16-pixel arrays with accurate spot tracking at the few-photon level. We also explore the performance trade-offs of orienting the top layer nanowires parallel and perpendicular to the bottom layer. The thermally coupled row-column scheme is readily able to scale to the kilopixel size with existing readout systems and, when combined with other multiplexing architectures, has the potential to enable megapixel scale SNSPD imaging arrays
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