Sample cells, light scattering detectors utilizing the sample cells, and methods for using the same are provided. The sample cell may include a body defining a flowpath extending axially therethrough. The flowpath may include a cylindrical inner section interposed between a first outer section and a second outer section. The first outer section may be frustoconical. A first end portion of the first outer section may be in direct fluid communication with the inner section and may have a cross-sectional area relatively smaller than a cross-sectional area at a second end portion thereof. The body may further define an inlet in direct fluid communication with the inner section. The inlet may be configured to direct a sample to the inner section of the flowpath.

A method for ascertaining a solid physical state of water on a roadway surface. The method encompasses: emitting light having at least two predefined wavelengths or predefined wavelength ranges which differ from one another; receiving a signal representing an intensity of a portion of the emitted light which is scattered back by the roadway surface to an optical sensor; ascertaining a solid physical state of water on a roadway surface based on a ratio of received values for light intensities of the respective predefined wavelengths or predefined wavelength ranges within the signal; classifying the solid physical form of water on the roadway surface by reconciling absolute values of the signal with a first predefined threshold value and/or by reconciling a signal-to-noise ratio of the signal with a second predefined threshold value; and using the ascertained information regarding the solid physical state of the water in the transportation device.

Disclosed is a method for determining a visibility using a sensor unit, in particular a lidar sensor, including having the sensor unit emit a transmission signal, capturing a received signal backscattered by an object, determining the distance from the object using the received signal, and determining the visibility on the basis of the ascertained distance from the object and/or the strength of the received signal.

An optical probe includes an optical housing, a transmitting lens and a receiving lens. The optical housing extends from a proximate end to an opposing distal end. The transmitting lens is disposed at the distal end and is configured to output a first transmitted signal beams having a first transmission axis and a second transmitted beam having a second transmission axis that is different from the first transmission axis. The receiving lens is disposed at the distal end and configured to receive the first and second reflected signal beams corresponding respectively to the first and second transmitted signal beams. The optical housing has formed therein a transmitting optical channel configured to communicate an input optical signal from the proximate end to the transmitting lens. A receiving optical channel separated from the transmitting optical channel communicates the first and second reflected signal beams to the proximate end.

A system comprises an optical air data system that measures aerosol and molecular scattering of light, and an optical instrument that measures aerosol and/or molecular scattering of light. A processor receives data from the air data system and from the optical instrument. The processor performs one or more signal analysis and data fusion methods comprising: (a) determining aerosol and/or molecular concentration from the received data, modifying a data analysis algorithm to optimize any remaining unknown parameters, and outputting enhanced air data parameters; (b) determining aerosol concentration from the received data, dynamically optimizing hardware settings in the air data system to enhance a signal level and avoid system saturation, and outputting enhanced air data parameters; or (c) determining aerosol and/or molecular concentration from the received data, estimating a confidence level of an air data algorithm, verifying optical health of the air data system, and reporting the optical health to a user.

An electronic device is described. The electronic device includes a housing, a set of one or more SMI sensors attached to the housing, and a processor. The set of one or more SMI sensors includes a set of one or more electromagnetic radiation emitters having a set of one or more resonant cavities and configured to emit a set of one or more beams of electromagnetic radiation. The set of one or more SMI sensors also includes a set of one or more detectors configured to generate indications of self-mixing within the set of one or more resonant cavities. The processor is configured to characterize, using the indications of self-mixing, an optical field speckle of a target. The processor is also configured to characterize, using the characterization of the optical field speckle, a surface quality of the target.

A device and method for observing an object, in particular a biological object includes a light source able to illuminate a sample. Under the effect of the illumination, the object emits back-scattered radiation that propagates to a screen, the area of which is larger than 100 cm.sup.2. The projection of the back-scattered radiation onto the screen forms an image representative of the back-scattered radiation, called a scattergram. An image sensor allows an image representative of the scattergram formed on the screen to be acquired.

A shared optics and telescope for transmitting a transmission beam and receiving a return signal is provided. The shared optics and telescope includes a pair of axicon lenses operable to shape the transmission beam into an annular beam having an outer diameter and an inner diameter, a secondary mirror operable to deflect the annular beam into a deflected annular transmission beam, and a primary mirror that includes an inner mirror portion and an outer mirror portion, the inner mirror portion operable to expand the deflected annular transmission beam, and the outer mirror portion operable to collect the return signal.

A system, wearable device, and method include a light emitter configured to emit light at a first wavelength of between approximately 900 and 1000 nanometers and at a second wavelength of approximately 1350 nanometers, a first light detector spaced at a first distance from the light emitter, and a second light detector spaced at a second distance from the light emitter, the second distance approximately twice the first distance. At least one of hydration and glycogen of muscle tissue is determinable based on a relationship between backscatter light from the muscle tissue as detected by the second light detector and backscatter light from non-muscle tissue as detected by the first light detector.

An illuminator/collector assembly can deliver incident light to a sample and collect return light returning from the sample. A sensor can measure ray intensities as a function of ray position and ray angle for the collected return light. A ray selector can select a first subset of rays from the collected return light at the sensor that meet a first selection criterion. In some examples, the ray selector can aggregate ray intensities into bins, each bin corresponding to rays in the collected return light that traverse within the sample an estimated optical path length within a respective range of optical path lengths. A characterizer can determine a physical property of the sample, such as absorptivity, based on the ray intensities, ray positions, and ray angles for the first subset of rays. Accounting for variations in optical path length traversed within the sample can improve accuracy.