An illuminator/collector assembly can deliver incident light to a sample and collect return light returning from the sample. A sensor can measure ray intensities as a function of ray position and ray angle for the collected return light. A ray selector can select a first subset of rays from the collected return light at the sensor that meet a first selection criterion. In some examples, the ray selector can aggregate ray intensities into bins, each bin corresponding to rays in the collected return light that traverse within the sample an estimated optical path length within a respective range of optical path lengths. A characterizer can determine a physical property of the sample, such as absorptivity, based on the ray intensities, ray positions, and ray angles for the first subset of rays. Accounting for variations in optical path length traversed within the sample can improve accuracy.

A gas sensor for measuring concentration of a predetermined gas includes a light source (2) arranged to emit pulses of light, a measurement volume (10), a detector (4) arranged to receive light that has passed through the measurement volume (10), and an adaptable filter (6) disposed between the light source (2) and the detector (4). The gas sensor has a measurement state in which it passes at least one wavelength band which is absorbed by the gas and a reference state in which said wavelength band is attenuated relative to the measurement state. A controller is connected to each of the light source, the detector and the adaptable filter to change the adaptable filter between one of said measurement state and said reference state to the other at least once during a gas sensor operation period.

This measurement system comprises: an infrared emission unit that emits first infrared light; an infrared reception unit that receives second infrared light, which is light obtained as a result of the first infrared light being reflected on a portion of the body of a measurement subject or being transmitted through a portion of the body of a measurement subject; an infrared current generation unit that applies a pulse current to the infrared emission unit; a duty control part that, on the basis of the intensity of the second infrared light, changes the duty of the pulse current applied by the infrared current generation unit; and a glucose level determination device that, on the basis of the intensity of the second infrared light, determines the blood glucose level of the measurement subject.

An apparatus for remote detection of plant growth dynamics is described. The apparatus includes an excitation LED (light emitting diode) module, a detection module and a controller module coupled to the excitation LED module and the detection module. The excitation LED module includes at least one LED. Each LED is configured to emit an excitation light in response to an excitation control signal. The excitation light has an emitted light spectrum. The detection module includes a photodetector configured to detect an initial chlorophyll a fluorescence (“ChlF”) light and an excited ChlF light from a plant species. The photodetector is further configured to convert the detected initial ChlF light into an initial detection electrical signal and the detected excited ChlF light into an excited detection electrical signal. The excited ChlF light is emitted from the plant species in response to receiving the excitation light. The controller module is configured to provide the excitation control signal to the excitation module, to capture the initial and excited detection electrical signals from the detection module and to determine chlorophyll fluorescence data based, at least in part, on the initial and excited detection electrical signals. The excitation LED module and the detection module are configured to be positioned remotely from the plant species. The chlorophyll fluorescence data represents a growth characteristic of the plant species.

System and methods for analyzing single molecules and performing nucleic acid sequencing. An integrated device includes multiple pixels with sample wells configured to receive a sample, which when excited, emits radiation. The integrated device includes at least one waveguide configured to propagate excitation energy to the sample wells from a region of the integrated device configured to couple with an excitation energy source. A pixel may also include at least one element for directing the emission energy towards a sensor within the pixel. The system also includes an instrument that interfaces with the integrated device. The instrument may include an excitation energy source for providing excitation energy to the integrated device by coupling to an excitation energy coupling region of the integrated device. One of multiple markers distinguishable by temporal parameters of the emission energy may label the sample and configuration of the sensor within a pixel may allow for detection of a temporal parameter associated with the marker labeling the sample.

Systems and indicators for determining the presence or absence of specific environmental, exposure, or biological conditions are provided. Indicators include a plurality of sensors, each sensor independently having a biological or chemical sensing modality to detect one or more analytes of interest. Analytes of interest include nucleic acids (e.g., DNA, RNA, etc.), proteins, peptides, and other amino acid chains and may come from a subject or the microbiome of a subject. The signals from the plurality of sensors may be processed to provide a readily understandable readout concerning a health condition or predisposition of a subject, such as cancer and exposure to coronavirus. The signals from the plurality of sensors may be colorimetric (e.g. a color change in response to the presence or absence of an analyte), and a plurality of colorimetric signals may be combined to provide a readily understandable colorimetric output. Indicators may be wearable.

An open path gas detector for detecting the presence of a target gas in the presence of fog or water vapor. A transmitter transmits flashes of optical energy along a path in an area under surveillance, including energy at a sample wavelength region at which the target gas is absorbed, at a reference wavelength region not significantly absorbed by the target gas, and at a synchronization wavelength region different from the first and second wavelengths. A receiver includes a sample channel responsive to the optical energy at the sample wavelength region, a reference channel responsive to optical energy at the reference wavelength region, and a third synchronization channel responsive to the optical energy at the synchronization wavelength region. The receiver detects the target gas and synchronizes operation of the receiver to the transmitter flashes of optical energy using the output of the synchronization channel.

An illuminator/collector assembly can deliver incident light to a sample and collect return light returning from the sample. A sensor can measure ray intensities as a function of ray position and ray angle for the collected return light. A ray selector can select a first subset of rays from the collected return light at the sensor that meet a first selection criterion. In some examples, the ray selector can aggregate ray intensities into bins, each bin corresponding to rays in the collected return light that traverse within the sample an estimated optical path length within a respective range of optical path lengths. A characterizer can determine a physical property of the sample, such as absorptivity, based on the ray intensities, ray positions, and ray angles for the first subset of rays. Accounting for variations in optical path length traversed within the sample can improve accuracy.

A high-throughput optofluidic device for detecting fluorescent droplets is disclosed. The device uses time-domain encoded optofluidics to detect a high rate of droplets passing through parallel microfluidic channels. A light source modulated with a minimally correlating maximum length sequences is used to illuminate the droplets as they pass through the microfluidic device. By correlating the resulting signal with the expected pattern, each pattern formed by passing droplets can be resolved to identify individual droplets.

An open path gas detector for detecting the presence of a target gas in the presence of fog or water vapor. A transmitter transmits flashes of optical energy along a path in an area under surveillance, including energy at a sample wavelength region at which the target gas is absorbed, at a reference wavelength region not significantly absorbed by the target gas, and at a synchronization wavelength region different from the first and second wavelengths. A receiver includes a sample channel responsive to the optical energy at the sample wavelength region, a reference channel responsive to optical energy at the reference wavelength region, and a third synchronization channel responsive to the optical energy at the synchronization wavelength region. The receiver detects the target gas and synchronizes operation of the receiver to the transmitter flashes of optical energy using the output of the synchronization channel.