A magnetic photomultiplier tube (PMT) system, comprising a PMT. The PMT comprising a photocathode for converting an impinging photon to a photoelectron, an anode, and at least two or a series of oppositely facing pairs of dynodes, wherein each pair is spaced apart from an adjacent pair, a first electric field being generated intermediate at least one pair of oppositely facing dynodes and a second electric field generated intermediate at least one adjacent pairs of dynodes. The PMT system comprises a magnetic field generated by a magnetic system, the PMT being positioned within the magnetic field.

A cytometer includes an avalanche photodiode, a switching power supply, a filter, and voltage adjustment circuitry. The switching power supply includes a feedback loop. The filter is electrically connected between the switching power supply and the avalanche photodiode. The voltage adjustment circuitry adjusts a voltage on the feedback loop based at least in part on a voltage measured between the filter and the avalanche photodiode.

An apparatus, including: a probe to interface with a surface of a tissue; a light source optically coupled to the probe, the light source directing light of at least 1000 nm into the tissue; a detector optically coupled to the probe, the detector to detect light based on scattering of light from the light source in the tissue, and the detector having a light sensitivity in a range of at least 1000 nm; a processor coupled to the detector, the processor to: receive a signal from the detector corresponding to the detected light from the light source, and determine a blood flow measurement from the region of interest using diffuse correlation spectroscopy based on the signal.

A system, apparatus and method of improved measurement of the SPF factor of sunscreen compositions. In one embodiment, a method of measuring the protection of a sunscreen composition includes exposing skin to a known intensity of light, measuring the amount of remitted light from the skin, applying sunscreen to the skin, exposing the skin to which the sunscreen has been applied the known intensity of emitted light of the spectrum of light from which the sunscreen is intended to protect the skin, measuring the amount of light remitted from the skin, and calculating a UltraViolet-A Protection Factor (UVA-PF) of the sunscreen by comparing the amount of light remitted from the skin with the sunscreen to the amount of light remitted from the skin without the sunscreen.

Disclosed herein is a photomultiplier tube (PMT) comprising: an electron ejector configured for emitting primary electrons in response to an incident photon; a detector configured for collecting electrons and providing an output signal representative of the incident photon; and a series of electrodes between the electron ejector and the detector, wherein each of the electrodes is configured for emitting secondary electrons in response to incident electrons, and each of the electrodes includes a bi-metal arc-shaped sheet.

Eye tracking system incorporates and/or uses one or more silicon photomultiplier (SiPM) sensor and an infrared module of a microelectromechanical (MEMs)-based scanner. The infrared module emits a beam of photons, where at least some of the photons are directed towards a user's eye while the eye tracking system is being used. The SiPM sensor(s) capture a reflection that emanates off of the user's eye.

A system, apparatus and method of improved measurement of the SPF factor of sunscreen compositions. In one embodiment, a method of measuring the protection of a sunscreen composition includes exposing skin to a known intensity of light, measuring the amount of remitted light from the skin, applying sunscreen to the skin, exposing the skin to which the sunscreen has been applied the known intensity of emitted light of the spectrum of light from which the sunscreen is intended to protect the skin, measuring the amount of light remitted from the skin, and calculating a UltraViolet-A Protection Factor (UVA-PF) of the sunscreen by comparing the amount of light remitted from the skin with the sunscreen to the amount of light remitted from the skin without the sunscreen.

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.

A fluorescence lifetime measurement apparatus according to an embodiment of the present invention includes an illumination light generation unit that generates illumination light, a fluorescence photon detection unit that collects fluorescence photons generated by illuminating a sample including fluorescent molecules with the illumination light, a conversion unit that converts the collected fluorescence photons into a first clock signal and converts illumination light that does not pass through the sample into a second clock signal, a first module that analyzes a fluorescence lifetime of the collected fluorescence photons from the conversion unit, a control unit that designates a range of interest (ROI) of the sample from the first module, and a second module that analyzes a fluorescence lifetime of fluorescence photons corresponding to the ROI.

A handheld luminometer system and assembly are shown and described. In one embodiment, an assembly includes a portable luminometer and a front end platform having a microcontroller circuit to communicate with a host device. Typically, the portable luminometer includes a sample port to accept a test sample holder, a photomultiplier assembly with at least one photomultiplier tube, and a base. The result is a luminometer assembly for use with a single-use test sample holder in communication with a host device.