An optical pulse to voltage signal converter may include a photodetector, a front end-circuit, and a signal processor. The front-end circuit may include a tunable loading network configured to convert a stream of current pulses from the photodetector into a stream of input voltage signals, at least one tunable voltage source configured to generate at least one stream of signals with at least one select voltage, and at least one amplifier coupled to the at least one tunable voltage source. The at least one amplifier may be configured to compare the stream of input voltage signals and the at least one stream of signals with the at least one select voltage to generate at least one stream of output voltage signals with a select duty-cycle phase and duty-cycle resolution. The amplifier may be further configured to output the at least one stream of output voltage signals to the signal processor.

A method and a detection circuit. The detection circuit may include (a) a photodiode that is configured to convert radiation to a photodiode current; (b) a photodiode bias circuit that is configured to bias the photodiode; (c) a dynamic resistance circuit that has a first terminal and a second terminal; (d) a transimpedance amplifier that is configured to amplify an output current of the dynamic resistance circuit to provide an output voltage, wherein the second terminal is coupled to a negative input port of the amplification circuit; and (e) a conductor that is coupled between the first terminal and an anode of the photodiode.

A UV detection device is removably attached to a surface of a structure and includes a photodetector to detect UV light incident on the structure. The UV detection device includes signal processing and a transmitter that wirelessly transmits UV detection data to a remote monitoring station where the detection signals are accumulated and analyzed to determine the total exposure of the structure to UV light.

In one example, a method comprises: enabling a photodiode to, in response to incident light, accumulate residual charge, and to transfer overflow charge to a first charge storage device and a second charge storage device when the photodiode saturates; disconnecting the second charge storage device from the first charge storage device; enabling the photodiode to transfer the residual charge to the first charge storage device to cause the charge sensing unit to output a first voltage; quantizing the first voltage to generate a first digital value to measure the residual charge; connecting the second charge storage device with the first charge storage device to cause the charge sensing unit to output a second voltage; quantizing the second voltage to generate a second digital value to measure the overflow charge; and generating a digital representation of the incident light intensity based on the first digital value and the second digital value.

A system for generating clock signals for a photonic quantum computing system includes a pump photon source configured to generate a plurality of pump photon pulses at a first repetition rate, a waveguide optically coupled to the pump photon source, and a photon-pair source optically coupled to the first waveguide. The system also includes a photodetector optically coupled to the photon-pair source and configured to generate a plurality of electrical pulses in response to detection of at least a portion of the plurality of pump photon pulses at the first repetition rate and a clock generator coupled to the photodetector and configured to convert the plurality of electrical pulses into a plurality of clock signals at the first repetition rate.

A summation circuit (1) for summing one or more signals received from a photomultiplier array is proposed. The summation circuit comprises one or more readout circuits (5) coupleable to one or more photodiodes of the photomultiplier array (2), respectively, and a channel summing module (50), coupled at one or more outputs of the one or more readout circuits, respectively, to sum the one or more signals provided by the one or more readout circuits. The one or more readout circuits are coupleable to the photodiode of the photomultiplier array. Each readout circuit (5) comprises one or more coefficient controllers (C1, C2) for controlling multiplying coefficients of the received signal. The coefficient controllers may be placed at the input and/or at the output of the readout circuits (5).

A system for generating clock signals for a photonic quantum computing system includes a pump photon source configured to generate a plurality of pump photon pulses at a first repetition rate, a waveguide optically coupled to the pump photon source, and a photon-pair source optically coupled to the first waveguide. The system also includes a photodetector optically coupled to the photon-pair source and configured to generate a plurality of electrical pulses in response to detection of at least a portion of the plurality of pump photon pulses at the first repetition rate and a clock generator coupled to the photodetector and configured to convert the plurality of electrical pulses into a plurality of clock signals at the first repetition rate.

An optical sensor includes at least one photodetector configured to be reverse biased at a voltage exceeding a breakdown voltage by an excess bias voltage. At least one control unit is configured to adjust the reverse bias of the at least one photodetector. A method of operating an optical sensor is also disclosed.

Systems for detecting light (e.g., in a flow stream) are described. Light detection systems according to embodiments include a photodetector, an input modulator configured to modulate signal input into the photodetector and an output modulator configured to modulate signal output from the photodetector. Photodetector arrays having a plurality of light detection systems, e.g., as described, are also provided. Methods for matching output signals from two or more photodetectors (e.g., a plurality of photomultiplier tubes in a photodetector array) are also described. Flow cytometer systems and methods for detecting light from a sample in a flow stream are provided. Aspects further include kits having two or more of the subject light detection systems.

In one example, a method comprises: enabling a photodiode to, in response to incident light, accumulate residual charge, and to transfer overflow charge to a first charge storage device and a second charge storage device when the photodiode saturates; disconnecting the second charge storage device from the first charge storage device; enabling the photodiode to transfer the residual charge to the first charge storage device to cause the charge sensing unit to output a first voltage; quantizing the first voltage to generate a first digital value to measure the residual charge; connecting the second charge storage device with the first charge storage device to cause the charge sensing unit to output a second voltage; quantizing the second voltage to generate a second digital value to measure the overflow charge; and generating a digital representation of the incident light intensity based on the first digital value and the second digital value.