A system and method to discriminate between a first preselected gas and at least one other preselected gas use of an absorption spectroscopy analyzer that includes a Herriott cell and a temperature sensitive light source. The light source operates at a temperature that emits a beam at a wavelength that corresponds to high absorption by a first preselected gas. When a predetermined level of this gas is detected in a gas sample, the analyzer changes the operating temperature of the light source to emit a beam at a wavelength that corresponds to high absorption by a second preselected gas. The second preselected gas can be a different isotope of the first preselected gas.

A spectrometry device includes a first converter that processes a reception signal based on an irradiation light from a first emitter, a second converter that processes a reception signal based on an irradiation light from a second emitter, and a controller that controls the first emitter and the second emitter. The reception signal based on the irradiation light irradiated from the first emitter includes a first reception signal and a second reception signal that each include information that relates to an optical spectrum. When the controller stops the operation of the second emitter, the first converter converts the first reception signal into a first digital signal and the second converter converts the second reception signal into a second digital signal.

Detector data representative of an intensity of light that impinges on a detector after being emitted from a light source and passing through a gas over a path length can be analyzed using a first analysis method to obtain a first calculation of an analyte concentration in the volume of gas and a second analysis method to obtain a second calculation of the analyte concentration. The second calculation can be promoted as the analyte concentration upon determining that the analyte concentration is out of a first target range for the first analysis method.

Provided is a spectroscopic apparatus including an encoder configured to output an orthogonal code, a light source configured to receive the orthogonal code and provide to a sample an optical signal encoded as a pattern corresponding to the orthogonal code, a detector configured to detect a output signal emitted from the sample, and a decoder configured to share the orthogonal code with the encoder and extract a valid signal corresponding to the sample based on a correlation between the orthogonal code and the output signal.

A method for operating an optical measuring system including a wavelength-tunable temperature-stabilized laser light source for measuring the concentration of a target gas in a measured gas, wherein an instantaneous base current I.sub.DC_ZG,act corresponding to a wavelength .sub.ZG of a target gas absorption line is set so that a wavelength distance .sub.DC defined during calibration between a target gas absorption line for a target gas and a reference gas absorption line for a reference gas is maintained. During operation, a temperature difference in the laser light source, defined in advance during calibration, between the operating points selected at the time of calibration of the reference gas, with a base current I.sub.DC_RG,cal, and the target gas, with a base current I.sub.DC_ZG,cal, is maintained by determining the required instantaneous base current I.sub.DC_ZG,act for the target gas, as a function of an instantaneous base current I.sub.DC_RG,act for the reference gas.

A system for measuring a liquid sample comprising biological material, the system comprising an integrating light collector for collecting light and for at least partially containing the sample; a light source for introducing light in the integrating light collector; a signal generator or modulator configured to cause a known modulation of the light output by the light source; a phase-sensitive detector for detecting scattered light in the integrating light collector; at least one of an exit port to allow un-scattered light to exit the integrating light collector, a beam dump, or a baffle arranged to absorb unscattered light; and a processor configured to analyse the detected modulated light to determine changes in the detected modulated light as a function of time thereby to determine at least one of: drug susceptibility of the biological material; a change in a number of cells in the sample; a change in cell state; a change in the biological material.

A system for measuring a sample comprising: an integrating sphere light collector (12) for collecting light and containing the sample; a light source (24) for introducing light in the integrating sphere light collector (12), wherein the light source (24) is operable to output light with a known modulation, preferably by using a signal generator (26); a detector (22) for detecting scattered light in the integrating sphere light collector (12) and generating a signal indicative of the scattered light, and a lock-in amplifier (28) operable use the known light modulation and the signal generated by the detector (22) to provide an output for analysis.

In swept source Raman (SSR) spectroscopy, a swept laser beam illuminates a sample, which inelastically scatters some of the incident light. This inelastically scattered light is shifted in wavelength by an amount called the Raman shift. The Raman-shifted light can be measured with a fixed spectrally selective filter and a detector. The Raman spectrum can be obtained by sweeping the wavelength of the excitation source and, therefore, the Raman shift. The resolution of the Raman spectrum is determined by the filter bandwidth and the frequency resolution of the swept source. An SSR spectrometer can be smaller, more sensitive, and less expensive than a conventional Raman spectrometer because it uses a tunable laser and a fixed filter instead of free-space propagation for spectral separation. Its sensitivity depends on the size of the collection optics. And it can use a nonlinearly swept laser beam thanks to a wavemeter that measures the beam's absolute wavelength during Raman spectrum acquisition.

Methods for controlling a plant detection system include determining a target phase delay based on a first phase delay of reflected portions of a first light beam and a second phase delay of reflected portions of a second light beam. A composite light beam comprising the first light beam and the second light beam is emitter towards bare soil, and reflected portions of the composite light beam are detected. An intensity of at least one of the first light beam or the second light beam is adjusted so that a phase delay of the composite light beam is approximately equal to the target phase delay.

Methods for controlling a plant detection system include determining a target phase delay based on a first phase delay of reflected portions of a first light beam and a second phase delay of reflected portions of a second light beam. A composite light beam comprising the first light beam and the second light beam is emitter towards bare soil, and reflected portions of the composite light beam are detected. An intensity of at least one of the first light beam or the second light beam is adjusted so that a phase delay of the composite light beam is approximately equal to the target phase delay.