A gas sensor (2) distinguishes between a target gas and a contaminant and includes a light source (8), a measurement volume (4), a detector (22), and an adaptable filter system (20) with a first optical filter and a second optical filter. The filter system switches between a first composite state, with both filters in a reference state, a second composite state, with the first filter in a first reference state and the second filter in a second measurement state, a third composite state with the first filter in a first measurement state and the second filter in a second reference state, and a fourth composite state, with both filters in a measurement state. The gas sensor detects a target gas and makes a determination as to a presence of the contaminant by comparing the respective detector signals, generated during at least three of the composite states, with each other.

A method of performing spectroscopic measurements provides an optical frequency comb, and directs the comb through or at a sample. The optical frequency comb is generated by gain switching a laser diode constructed from Gallium Nitride and related materials. Various techniques are described for manipulating the comb source to achieve desired benefits for spectroscopy.

A method of determining the concentration of a species in a portion of a furnace atmosphere is described. The method comprises the steps of measuring first, second and third intensities of electromagnetic radiation in the furnace at first, second and third wavelengths respectively. The third wavelength is selected to be representative of absorption of electromagnetic radiation by the species. A fourth intensity of electromagnetic radiation is calculated, being an estimate of the intensity of electromagnetic radiation in the furnace at the third wavelength absent any absorbing species in the furnace atmosphere. The third intensity and the fourth intensities are used to determine a parameter that is proportional to the concentration of absorbing species in the portion of the furnace atmosphere. Apparatus for carrying out the method is also described.

In an analysis device that irradiates light from three or more light sources onto a cell, embodiments proposed herein prevent a reduction in the intensity of light from each light source, and are provided with at least a first light source, a second light source, and a third light source, and an optical system that guides light from the respective light sources onto a cell. The optical system is provided with a second light source optical element that reflects the light from the first light source and transmits the light from the second light source, and a third light source optical element that reflects the light from the first light source that has been reflected by the second light source optical element and the light from the second light source that has been transmitted through the second light source optical element, and transmits the light from the third light source.

The present disclosure provides a detection system for detecting matter and distinguishing specific matter from other matter. The detection system comprises at least one light source arranged to emit one or more light beams having a known wavelength or wavelength range. Further, the detection system comprises at least one optical element configured to direct the one or more light beams onto a plurality of locations within an area of interest including the matter. The detection system also comprises a detector for detecting intensities of the one or more light beams reflected at the plurality of locations within the area of interest including the matter. In addition, the detection system comprises an outcome determination system. The system is arranged to obtain information indicative of at least a portion of a shape of at least some of the matter based on detected light intensities of the one or more light beams reflected at the plurality of locations. The system is also arranged to obtain information indicative of a spectral intensity distribution based on detected light intensities of the one or more light beams reflected at the plurality of locations. The outcome determination system is arranged determine whether the matter is specific matter based on the information indicative of at least a portion of a shape of at least some of the matter and based on the information indicative of a spectral intensity distribution.

A detecting device of the present disclosure includes a first light-emitting unit that emits first light having a green wavelength band, a second light-emitting unit that emits second light having a wavelength band higher than the green wavelength band, a first light-receiving unit that receives the first light emitted from the first light-emitting unit and emitted from a biological body, and a second light-receiving unit that receives the second light emitted from the second light-emitting unit and emitted from the biological body, in which the first light-receiving unit includes a bandpass filter that selectively transmits the first light, and a distance from the first light-emitting unit to the first light-receiving unit is shorter than a distance from the second light-emitting unit to the second light-receiving unit.

A sensor for monitoring the quality of oil in mechanical machinery is provided. The sensor includes a portion that is sealed from the oil which contains electric circuitry to process signals received from the sensing elements. Another portion of the sensor is exposed to the oil and contains one or more sensing elements to sense one or more properties of the oil. The sensed properties may include electrical properties, temperature properties and/or optical properties.

A body fluid analysis device includes a light source, a detector, a normalization part, and a calculation part. The light source is configured to emit light at a first wavelength and light at a second wavelength different from each other to a body fluid. The detector is configured to receive light emitted from the light source and transmitted through the body fluid or light reflected by the body fluid, and is configured to detect intensity of the light. The normalization part is configured to calculate a ratio of an intensity of light emitted at the second wavelength to an intensity of light emitted at the first wavelength, both of which are detected by the detector. The calculation part is configured to calculate a concentration of a predetermined component included in the body fluid on the basis of the ratio calculated by the normalization part.

The present disclosure provides a detection system for detecting matter and distinguishing specific matter from other matter. The detection system comprises at least one light source arranged to emit one or more light beams having a known wavelength or wavelength range. Further, the detection system comprises at least one optical element configured to direct the one or more light beams onto a plurality of locations within an area of interest including the matter. The detection system also comprises a detector for detecting intensities of the one or more light beams reflected at the plurality of locations within the area of interest including the matter. In addition, the detection system comprises an outcome determination system. The system is arranged to obtain information indicative of at least a portion of a shape of at least some of the matter based on detected light intensities of the one or more light beams reflected at the plurality of locations. The system is also arranged to obtain information indicative of a spectral intensity distribution based on detected light intensities of the one or more light beams reflected at the plurality of locations. The outcome determination system is arranged determine whether the matter is specific matter based on the information indicative of at least a portion of a shape of at least some of the matter and based on the information indicative of a spectral intensity distribution.

Systems and methods herein provide low power non-dispersive infrared (NDIR) gas sensors. The gas sensors comprise a thin film plasmonic light source that produces a time modulated parallel light beam at multiple selected wavelengths. The parallel light beam from the light source passes through a gas chamber without using focusing or collimating optical components. The gas sensors are continuously self-calibrated against environmental changes, such as temperatures and relative humidity, and aging. The gas sensors are suitable for use in hazardous environments because their low power and small thermal mass reduces the risk of explosion. The gas sensors can be integrated into conventional mobile device platforms.