A method for infrared chemical imaging through nondegenerate two-photon absorption includes a step of providing pulsed or continuous wave radiation having pumping photons at near-infrared wavelength and providing pulsed or continuous wave radiation that having mid-infrared photons at a mid-infrared wavelength with peak intensities less than 50 W/cm.sup.2. The mid-infrared photons are directed onto a target sample. The method also includes a step of spatially and temporally overlapping the mid-infrared photons with the pumping photons. The mid-infrared photons and the pumping photons are directed onto a camera having an array or matrix of imaging devices. Characteristically, the sum of photon energy for each temporally and spatially overlapping mid-infrared photons and pumping photons is greater than or equal to the bandgap energy.

A drug scanning and identification system including a spectrometer, a drug holder, a mobile device and a drug identification model is provided. The spectrometer includes a light source, a diffraction grating, a light-absorption element, a wavelength selector, and a single-point photodetector. The drug holder includes a transparent area and a light-absorption area. The drug is disposed on the transparent area. The light-absorption area surrounds the transparent area. The mobile device is adapted to send a control command to trigger the spectrometer scanning the drug so as to obtain spectrum data of the drug. The spectrometer is adapted to transmit the spectrum data of the drug to the drug identification model. The drug identification model is adapted to identify the spectrum data of the drug such that the drug identification model generates an identification result. The identification result is displayed by the mobile device.

A dual-comb spectrometer comprising two lasers outputting respective frequency combs having a frequency offset between their intermode beat frequencies. One laser acts as a master and the other as a follower. Although the master laser is driven nominally with a DC drive signal, the current on its drive input line nevertheless oscillates with an AC component that follows the beating of the intermode comb lines lasing in the driven master laser. This effect is exploited by tapping off this AC component and mixing it with a reference frequency to provide the required frequency offset, the mixed signal then being supplied to the follower laser as the AC component of its drive signal. The respective frequency combs in the optical domain are thus phase-locked relative to each other in one degree of freedom, so that the electrical signals obtained by multi-heterodyning the two optical signals are frequency stabilized.

The present disclosure provides for an apparatus for measuring optical properties of liquid samples. The apparatus includes a sample chamber and a spectrometer optically coupled with the sample chamber. One or multiple sources of electromagnetic radiation are positioned relative to the sample chamber to direct electromagnetic radiation through the sample chamber to measure the color, haze, and/or clarity of the sample. Also provided is a method for measuring optical properties of liquid samples, including inserting a cuvette containing a liquid sample into the sample chamber of the apparatus, and directing electromagnetic radiation from the one or more sources and through the sample to measure the color, haze, and/or clarity of the sample. The apparatus and methods may be used to analyze various samples, such as petroleum-based fluids, including fuels and lubricants.

A dual-comb spectrometer comprising two lasers outputting respective frequency combs having a frequency offset between their intermode beat frequencies. One laser acts as a master and the other as a follower. Although the master laser is driven nominally with a DC drive signal, the current on its drive input line nevertheless oscillates with an AC component that follows the beating of the intermode comb lines lasing in the driven master laser. This effect is exploited by tapping off this AC component and mixing it with a reference frequency to provide the required frequency offset, the mixed signal then being supplied to the follower laser as the AC component of its drive signal. The respective frequency combs in the optical domain are thus phase-locked relative to each other in one degree of freedom, so that the electrical signals obtained by multi-heterodyning the two optical signals are frequency stabilized.

Provided is a system for measuring gas temperature and component concentrations in a combustion field based on optical comb. The system includes two pulse laser devices, two continuous laser devices, a beam splitting device, a measurement path, an interference signal detecting device, an optical processing and electrical processing device and a signal acquisition and analysis device. The measurement path refers to the combustion field to be measured. The interference signal detecting device outputs an interference signal. The optical processing and electrical processing device includes several optic elements and electrical elements, and outputs an adaptive compensation signal and an asynchronous sampling clock signal after a series of processing on output of the two pulse laser devices and two continuous laser devices. The signal acquisition and analysis device outputs the measurement result based on the adaptive compensation signal, the asynchronous sampling clock signal and a stable interference signal.

The invention comprises a method and apparatus for sampling a common tissue volume and/or a common skin layer skin of a person as a part of noninvasive analyte property determination system, comprising the steps of: providing an analyzer, comprising at least three detectors at least partially embedded in a probe housing, the probe housing comprising a sample side surface, the detectors including a first and second range of detection zones of differing radial distances from a first illumination zone and second illumination zone, respectively coupled to separate sources; repetitively illuminating the illumination zones of the skin with photons in a range of 1200 to 2500 nm; and detecting portions of light from the sources with the at least three detectors, the detectors positioned on a common line with the sources.

A photonic integrated circuit-based dual frequency comb source, an integrated system for dual comb spectroscopy and corresponding method are disclosed. The dual comb source includes, on a same substrate of the photonic integrated circuit, a first and second semiconductor integrated mode-locked laser, a master laser, and connection arrangement between the master laser and each of the first and second mode-locked laser. The master laser is configured for generating a lasing line for simultaneous optical injection-locking of the first and second mode-locked laser, the first and second mode-locked laser are configured for generating a first and second frequency comb respectively, and the connection arrangement is suitable for coherently transferring lasing light from the master laser to each mode-locked laser. The mode-locked lasers include a gain section and a saturable absorber section to provide mode-locking, and an extended optical cavity formed in the substrate.

An endoscopic imaging system for use in a light deficient environment includes an imaging device having a tube, one or more image sensors, and a lens assembly including at least one optical elements that corresponds to the one or more image sensors. The endoscopic system includes a display for a user to visualize a scene and an image signal processing controller. The endoscopic system includes a light engine having an illumination source generating one or more pulses of electromagnetic radiation and a lumen transmitting one or more pulses of electromagnetic radiation to a distal tip of an endoscope.

Systems, methods, and devices for hyperspectral imaging with increased dynamic range are disclosed. A system includes an emitter for emitting pulses of electromagnetic radiation and an image sensor comprising a pixel array for sensing reflected electromagnetic radiation, wherein the pixel array comprises a plurality of pixels each configurable as a short exposure pixel or a long exposure pixel. The system includes a controller comprising a processor in electrical communication with the image sensor and the emitter. The system is such that at least a portion of the pulses of electromagnetic radiation emitted by the emitter comprises one or more of electromagnetic radiation having a wavelength from about 513 nm to about 545 nm, electromagnetic radiation having a wavelength from about 565 nm to about 585 nm, or electromagnetic radiation having a wavelength from about 900 nm to about 1000 nm.