The disclosure relates to a quantum detector configured to receive a microwave signal from a microwave source. The quantum detector comprises a main element formed by a main Josephson junction and a Josephson transmission line which is coupled to the main element for outputting a measurement signal. The Josephson transmission line comprises at least a first set of JTL elements and a second set of JTL elements. The capacitively shunted Josephson junction in each JTL element in the first set is weakly damped, and the JTL element in the second set are more strongly damped than the JTL elements in the first set.

A system counts photon interactions in an array of photosensitive diodes and addresses the issue of improving position resolution. Every photo-detector diode of the array is connected to a readout unit cell containing a high-gain charge-to-voltage amplifier, a shaper, at least two comparators with independent thresholds and at least one interpixel communication logic, receiving as input signals from comparator outputs of the same readout unit cell and of the neighboring readout unit cells. This logic is then connected to at least one counter, each counter followed by a counter readout. By means of the digital interpixel communication logic and the set of comparators with different thresholds in every readout unit cell, it is possible to determine the photon hit position in the detector with a higher position resolution than the physical photo-detector size including the removal of the corner effect in pixel detectors.

A single photon avalanche diode (SPAD) has a cathode coupled to a high voltage supply and an anode coupled to a first node. A photodetection circuit includes: a first n-channel transistor having a drain coupled to the first node, a source coupled to ground, and a gate coupled to a third node; a second n-channel transistor having a drain coupled to the first node, a source coupled to ground, and a gate coupled to a second node; and an inverter having an input coupled to the first node and an output coupled to an intermediate node. A current starved inverter has an input coupled to the intermediate node and an output coupled to the second node, a logic gate has inputs coupled to the intermediate node and the second node, and an output coupled to the third node.

An evaporatively cooled device and a system including the same. In some embodiments, the system includes an oligolayer conductive sheet; a superconductor; a tunneling barrier, between the oligolayer conductive sheet and the superconductor; and a bias circuit, configured to apply a bias voltage across the tunneling barrier, the bias voltage being less than a gap voltage of the superconductor and greater than one-half of the gap voltage of the superconductor.

A single photon detector (SPD) includes a resonator to store probe photons at a probe wavelength and an absorber disposed in the resonator to absorb a signal photon at a signal wavelength. The absorber is also substantially transparent to the probe photons. In the absence of the signal photon, the resonator is on resonance with the probe photons, thereby confining the probe photons within the resonator. Absorption of the signal photon by the absorber disturbs the resonant condition of the resonator, causing the resonator to release multiple probe photons. A photodetector (PD) then detects these multiple probe photons to determine the presence of the signal photon.

An optical device is provided. The optical device includes a time-of-flight (TOF) sensor array, a photon conversion thin film, and a light source. The photon conversion thin film is disposed above the time-of-flight sensor array. The light source emits light with a first wavelength towards the photon conversion thin film to be converted into light with a second wavelength received by the time-of-flight sensor array. The second wavelength is longer than the first wavelength.

An optical sensing apparatus is provided. A bias-voltage generating circuit provides a first bias voltage and a second bias voltage to a photo-sensing diode when the optical sensing apparatus is respectively in a first mode and a second mode, such that the photo-sensing diode provides a time-of-flight ranging signal in the first mode and an ambient-light sensing signal in the second mode. A quenching circuit provides the time-of-flight ranging signal to a ranging signal processing circuit in the first mode, quenches the photo-sensing diode, and provides the ambient-light sensing signal to a light-sensing signal processing circuit in the second mode.

Single-photon detector apparatus comprising a large core optical fiber with a core diameter larger than 8 .Math.m, a small core optical fiber with a core diameter smaller or equal to 5 .Math.m, a taper between the large core optical fiber and the small core optical fiber, a superconducting nanowire having a surface area configured to receive all photons emitted from the small core optical fiber and cost effective and high yield method for manufacturing such.

The present invention provides a time-resolved single-photon counting apparatus, including an excitation light source for generating pulsed excitation light, a specimen optics for collecting an optical signal caused by irradiating the pulsed excitation light to a specimen, a photoelectric converter for photoelectrically converting the optical signal to generate an analog single-photon signal, an analog-to-digital (AD) signal converter for sampling the analog single-photon signal to convert the same into a digital single-photon signal, a digital photon-discrimination and timing detector for generating a photon-discrimination signal by discriminating the single-photon property of the digital single-photon signal to count a pulse time point of the digital single-photon signal to generate a delay time signal having delay time information, and a time-signal processor for counting valid single-photon detection events according to the delay time with reference to the photon-discrimination signal.

A light sensor includes an integrated circuit chip and a boost DC/DC converter. The integrated circuit chip supports an array of pixels, each pixel including a SPAD. The boost DC/DC converter delivers to the SPADs a bias potential capable of placing the SPADs in Geiger mode. The boost DC/DC converter includes an inductive element, a first switch, a second switch, and a circuit for controlling on/off switching of the first switch. The inductive element and the first and second switches are arranged outside of the integrated circuit chip while the control circuit forms part of the integrated circuit chip.