The present disclosure describes a method and apparatus of measuring dynamic light scattering of a sample. In an embodiment, the apparatus includes a platen, a light source underneath the platen and configured to emit emitted light through the platen and into the sample, collector optics underneath the platen and configured to capture scattered light, and an optical absorber configured to be in contact with the sample, configured to absorb transmitted light, and configured to redirect reflected light away from the collector optics. In an embodiment, the method includes depositing a sample on a platen, emitting emitted light from a light source underneath the platen through the platen and into the sample, capturing via collector optics underneath the platen scattered light, contacting the sample with an optical absorber, absorbing via the absorber transmitted light, and redirecting via the absorber reflected light away from the collector optics.

Disclosed is a transient-state THz spectrometer applied to cells and biological macromolecules, including a femtosecond laser amplifier. A femtosecond laser output by the femtosecond laser amplifier is divided into two beams of pump light and probe light after passing through a beam splitter of which a transmission-reflection ratio is 7:3, the pump light is focused to irradiate a gap between electrodes of a nonlinear photoconductive antenna and emit a terahertz wave after successively passing through a half wave plate, a silver-plated reflector and a first lens, the terahertz wave forms a terahertz wave collineation after successively passing through a second lens, a slab waveguide, a third lens and an ITO film, the terahertz wave collineation and the probe light form a probe light collineation of wavefront tilt which is perpendicularly incident on a ZnTe crystal and detected and recorded by using a CCD camera.

Modular docking station and methods for sampling and monitoring gas and other fluids, where a sampling device is able to be removably attached to the docking station, thereby allowing the sampling device to be replaced without having to remove or disconnect the docking station from the rest of the sampling system. This allows the docking station to remain connected to the rest of the system with minimal or no interruption and reduces maintenance costs and time when replacing the sampling device.

Disclosed is a transient-state THz spectrometer applied to cells and biological macromolecules, including a femtosecond laser amplifier. A femtosecond laser output by the femtosecond laser amplifier is divided into two beams of pump light and probe light after passing through a beam splitter of which a transmission-reflection ratio is 7:3, the pump light is focused to irradiate a gap between electrodes of a nonlinear photoconductive antenna and emit a terahertz wave after successively passing through a half wave plate, a silver-plated reflector and a first lens, the terahertz wave forms a terahertz wave collineation after successively passing through a second lens, a slab waveguide, a third lens and an ITO film, the terahertz wave collineation and the probe light form a probe light collineation of wavefront tilt which is perpendicularly incident on a ZnTe crystal and detected and recorded by using a CCD camera.

Techniques for detecting cannabinoid, opioid, and virus aerosols in an exhaled breath are provided. An example method of identifying a virus-containing aerosol in exhaled breath includes capturing a breath input in an aerosol filter cartridge, disposing the aerosol filter cartridge in an optical path in a spectroscopy system, detecting one or more infrared spectral features of the breath input with the spectroscopy system, and identifying the virus-containing aerosol based on the one or more infrared spectral features.

Techniques for detecting cannabinoid, opioid, and virus aerosols in an exhaled breath are provided. An example method for analyzing exhaled breath includes receiving an aerosol breath sample, concentrating the aerosol breath sample onto an infrared-transparent coupon with an electrostatic precipitator, disposing the infrared-transparent coupon in an optical path of a spectroscopy system, detecting one or more infrared spectral features of the concentrated aerosol breath sample with the spectroscopy system, and analyzing the aerosol breath sample based on the one or more infrared spectral features.

A short-pulse, narrowband, line-selectable and tunable solid-state laser is described. The device requires a pump source, an active solid-state laser medium, an enclosing cavity, mirrors to contain the light, a method of removing the pulse from the cavity, a wavelength selection system, and a laser linewidth narrowing system. One implementation of this is an Er:YAG laser, side pumped by semiconductor lasers in the erbium absorption band near 1475 nm, with an intracavity etalon and a switchable spectral filter. To remove the pulse from the cavity, cavity dumping issues, which assures constant pulse energy and pulse length over a range of repetition rates, in this case from 100 Hz to 20 kHz. Line selection is obtained by use of wavelength filters and fine tuning with an etalon, which also acts as the linewidth narrowing system.

Super continuum light having a continuous spectrum over at least 1100 to 1300 nm is emitted from a pulsed light source, is pulse-stretched by a stretching element such that a relationship between a wavelength and an elapsed time in one pulse is one to one, and is radiated to a product. The light transmitted through the product is received by a light receiver, and output data is input to the determination unit. A quality determination program of the determination unit calculates an absorption spectrum from the output data, quantifies the absorption spectrum by chemometrics, and compares the absorption spectrum with a reference value to determine quality. The product determined to be a defective product is excluded by an exclusion mechanism.

According to an example aspect of the present invention, there is provided a method of detecting carbon dioxide in a gaseous sample, the method comprising: flowing the gaseous sample through an anion exchange resin that is capable of selectively adsorbing CO.sub.2 present in the gaseous sample; releasing the adsorbed CO.sub.2 from the resin by heating the resin to a temperature in the range 80 to 250° C. to obtain a concentrated gaseous sample; determining the amount of an isotopic form of CO.sub.2 in the concentrated gaseous sample by infrared absorption spectroscopy.

A photo-acoustic gas sensor using a method for modulating the wavelength of the laser radiation, the modulation being obtained via judicious use of an electric current, called the generation current, which pumps the one or more laser sources, and is configured to cause the one or more laser sources to operate in pulsed mode, and of a current, called the base current, which takes non-zero values between each laser pulse with a lower magnitude than the magnitude of the generation current, the magnitude of base current being modulated so that the one or more laser sources emit, into the cell, light radiation having a wavelength that varies periodically about a central wavelength so as to take, at regular intervals, a value specifically suitable for the excitation of a gas to be detected, whereby an interaction between the light radiation and the gas to be detected contained in the cell induces the generation of acoustic waves at a resonant frequency of the cell.