Provided is a frequency domain (FD)-based multi-wavelength bio-signal analyzing apparatus including: four or more light sources configured to irradiate frequency-modulated light at four or more different discrete wavelengths; at least one light detector configured to detect an output light reflected and introduced from a subject; and a processing circuit connected to the four or more light sources and the at least one light detector and configured to calculate a scattering coefficient and an absorption coefficient at each discrete wavelength based on an output light detected by the at least one light detector and calculate a concentration of a chromophore present in the subject based on the scattering coefficient and the absorption coefficient at each discrete wavelength. Herein, the processing circuit drives at least two of the four or more light sources based on the chromophore present in the subject.

A measurement system comprises a pulsed laser diode array that includes one or more Bragg reflectors, and wherein the light generated by the array penetrates tissue comprising skin. At least some of the wavelengths of light are in the near infrared. The detection system is synchronized to the laser diode array and comprises an infrared camera and a first receiver comprising a plurality of detectors. The first receiver comprises one or more detector arrays and performs a time-of-flight measurement. The measurement system generates an image, the detection system non-invasively measures blood in blood vessels within or below a dermis layer within the skin based at least in part on near-infrared diffuse reflection from the skin, and the detection system measures absorption of hemoglobin between 700 and 1300 nanometers wavelength range. A processor compares the absorption of hemoglobin between different tissue spatial locations, and the measurement system processes the time-of-flight measurement.

A modular testing device includes a base unit and an expansion unit that communicates with the base unit. The expansion unit includes a housing, a receptacle in which a sample holder containing a biological sample and reagent mixture can be placed, and an optical assembly positioned in the housing. The optical assembly is configured to amplify and detect a signal from the biological sample and reagent mixture. Data that is collected in the optical assembly is communicated to the base unit.

A detector is for identifying chemicals in a sample. The detector may include a photodetector comprising SiC semiconductor material and configured to have an acceptor energy band of range E.sub.aE.sub.a to E.sub.a+E.sub.a. The SiC semiconductor material may be doped with a dopant to exceed a threshold dopant concentration level. The photodetector may be configured to receive fluorescence information from the sample.

A hand held spectrometer is used to illuminate the object and measure the one or more spectra. The spectral data of the object can be used to determine one or more attributes of the object. In many embodiments, the spectrometer is coupled to a database of spectral information that can be used to determine the attributes of the object. The spectrometer system may comprise a hand held communication device coupled to a spectrometer, in which the user can input and receive data related to the measured object with the hand held communication device. The embodiments disclosed herein allow many users to share object data with many people, in order to provide many people with actionable intelligence in response to spectral data.

The present invention enables an analysis device that utilizes light absorption to measure concentrations of target components by means of a simple calculation, and without any complex spectrum calculation processing being required, and analyzes target components that are contained in a sample, and is provided with a light source that emits modulated light whose wavelength is modulated relative to a central wavelength using a predetermined modulation frequency, a photodetector that detects an intensity of sample light obtained when the modulated light is transmitted through the sample, a correlation value calculation unit that calculates correlation values between intensity-related signals that are related to the intensity of the sample light, and predetermined feature signals, and a concentration calculation unit that calculates concentrations of the target components using the correlation values obtained by the correlation value calculation unit.

A photoacoustic gas analyzer, including: a gas chamber to receive a gas to be analyzed; a radiation source that emits into the gas chamber electromagnetic radiation with a time-varying intensity to excite gas molecules of N mutually different gas types the concentrations of which are to be determined in the received gas, wherein the radiation source is operable in N mutually different modes, each mode having a unique emission spectrum different from the emission spectra of the other N-1 modes; an acoustic-wave sensor that detects acoustic waves generated by the electromagnetic radiation emitted into the gas to be analyzed; and a control unit to operate the radiation source in the different modes respectively to emit electromagnetic radiation with a time-varying intensity; to receive in each mode from the acoustic-wave sensor signals; and to determine from the signals received in each mode the concentrations of the N mutually different gas types.

A photoacoustic gas analyzer including a gas chamber to receive a gas sample, a radiation source to emit an electromagnetic radiation adapted to excite N different types of gas molecules in the gas sample, the concentrations of which are to be determined, an acoustic-wave sensor to detect acoustic waves generated by the irradiated gas, and a control unit. The control unit controls the radiation source to emit electromagnetic radiation with a time-varying intensity and to modulate the frequency at which the intensity is varied with a modulation signal having at least N different values, to receive from the acoustic-wave sensor signals indicative of acoustic waves generated by the irradiated gas, to determine at least N mutually different signal amplitudes each associated with a respective N mutually different frequencies at which the intensity of the emitted electromagnetic radiation is varied, and to determine the concentrations of the N different gas types.

A detector is for identifying chemicals in a sample. The detector may include a photodetector comprising SiC semiconductor material and configured to have an acceptor energy band of range E.sub.aE.sub.a to E.sub.a+E.sub.a. The SiC semiconductor material may be doped with a dopant to exceed a threshold dopant concentration level. The photodetector may be configured to receive fluorescence information from the sample.

Disclosed is a method for measuring the absorbance of light of a substance in a solution in a measuring cell, said method comprising the steps of: transmitting a first light beam from a light source towards a beam splitter; dividing the first light beam into a signal light ray and a reference light ray by the beam splitter; modulating the signal light ray; modulating the reference light ray; providing the measuring cell such that the signal light ray passes through the measuring cell; detecting a signal in a detector, which signal is the combined signal intensity of the signal light ray and the reference light ray detected by the detector; performing synchronous detection of the detected signal in order to reconstruct the intensities of the signal light ray and the reference light ray from the combined signal detected by the detector, said synchronous detection being based on the modulation performed to the signal light ray and the reference light ray. Disclosed also is a measuring device for carrying out said method