The invention relates to methods and apparatus for detecting properties of suspended particles. Embodiments disclosed include an optical instrument (200) for detecting properties of a sample, comprising: a sample cell (103) for holding a sample of a particulate dispersion; a coherent light source (101) configured to illuminate the sample in the sample cell (103); a light intensity detector (104, 106) positioned to receive and measure an intensity of light from the coherent light source (101) elastically scattered by the sample in the sample cell (103); and a spectral light detector (212) positioned and configured to receive and measure a range of wavelengths of light from the coherent radiation source (101) inelastically scattered by the sample in the sample cell (103).

The present invention provides a meter and method of use for measuring an optical attenuation coefficient in a liquid medium. In operation, a collimated beam, produced by a laser of the attenuation meter apparatus, propagates thru the liquid medium with filtered back-scattered light arriving at a camera of the meter. A light image is formed at a focal plane of the camera. The light image is recorded and analyzed by a microcomputer to provide optical beam attenuations coefficients.

Apparatus and associated methods relate to determining metrics of water particles in clouds by directing light pulses at a cloud and measuring a peak, a post-peak value and a high-frequency fluctuation of light signals reflected from the cloud. The light pulses include: a first pulse having circularly polarized light of a first wavelength; and a second pulse of a second wavelength. The reflected light signals include: a first reflected light signal having left-hand circular polarization of the first wavelength; a second reflected light signal having right-hand circular polarization of the first wavelength; and a third reflected light signal of the second wavelength. An extinction coefficient and a backscatter coefficient are determined based on the measured peak and post-peak slopes of the first and second reflected light signals. The measured high-frequency fluctuations of the three reflected light signals can be used to calculate cloud particle sizes.

Turbidity measurement systems and methods of using the same are described. A turbidity measurement system comprises a vessel configured to hold a wellbore fluid, wherein a porous media is positioned in the vessel; a light source positioned to direct light at the vessel; a light detector positioned to measure light intensity of light emitted by the light source and passing through the vessel; a backscatter detector configured to measure the light intensity of reflected light emitted from the light source; and a computer system communicatively coupled to at least one of the light source, light detector, or light detector.

A multi-function imaging system comprises a light sensor and a software defined light source to enable real-time automatic adjustment of various parameters of the one or more light sources. The system is realized in a single unit, or as multiple co-located units, thus reducing the cost of having such multiple functions. The system is capable of self-calibrating in the field to enable accurate imaging.

A measuring apparatus is provided with: an irradiator configured to irradiate fluid with light; a first light receiver configured to receive a forward scatter component of scattered light scattered by the fluid; a second light receiver configured to receive a backscatter component of the scattered light; a third light receiver configured to receive a side scatter component of the scattered light; and an outputting device configured to output fluid information about the fluid, which is obtained on the basis of light receiving signals of the first light receiver, the second light receiver, and the third light receiver. According to this measuring apparatus, it is possible to output accurate fluid information because of the use of the forward scatter component, the backscatter component, and the side scatter component of the scattered light.

The subject matter of this specification can be embodied in, among other things, a method that includes separating, from a few mode optical fiber, a collection of backscattered Rayleigh signals based on a vibration of the few mode optical fiber at a vibration frequency at a first location along the few mode optical fiber, separating, from the few mode optical fiber, a collection of backscattered Stokes Raman signals and Anti-Stokes Raman signals based on a temperature of the few mode optical fiber at a second location along the few mode optical fiber, detecting the separated Rayleigh signals and Raman signals, determining, based on detecting the collection of backscattered Rayleigh traces, at least one of the first location, the vibration frequency, and an amplitude of the vibration, and determining, based on the detecting the collection of backscattered Raman signals, the temperature at the second location.

An exemplary catheter can be provided, which can include, for example a source fiber(s) configured to (i) receive a near infrared spectroscopic (NIRS) radiation, and (ii) provide the NIRS radiation to a portion(s) of a sample(s), a detection fiber(s) configured to receive a return radiation from the sample(s) that can be based on the NIRS radiation that was provided to the portion(s) of the sample(s), and an ablation electrode(s) configured to ablate the sample(s) based on the return radiation. The source fiber(s), the detection fiber(s), and the ablation electrode(s) can be integrated into the single sheath. The ablation electrode(s) can be a radiofrequency ablation electrode.

Provided is an apparatus for measuring particulate matter, the apparatus including an air inflow device configured to receive air including particulate matter particles, two or more light sources configured to respectively emit light of different wavelengths to the air received, a pattern measuring device configured to measure scattering patterns for each wavelength of light based on detecting light that is forward-scattered by the particulate matter particles and light that is back-scattered by the particulate matter particles, and a processor configured to obtain a size of the particulate matter particles and a concentration of the particulate matter particles based on the scattering patterns for each wavelength of light.

Systems and methods for acquiring images of a sample are provided. According to an aspect of the invention, a system includes a first light source that emits first light having a first wavelength as a temporally continuous beam; a second light source that emits second light having a second wavelength as a temporally modulated beam; and a scanning mirror that raster scans the first light across a sample during a raster scan period, and projects a structured light pattern of the second light onto the sample during the raster scan period. A first image of the sample is generated from at least a portion of the first light that is backscattered from the sample during the raster scan period, and a second image of the sample is generated from at least a portion of the second light that is backscattered from the sample during the raster scan period.