A moisture sensing device includes: a light source part; a projection optical system configured to project illumination light emitted from the light source part, onto a road surface; a photodetector configured to receive reflected light of the illumination light reflected by the road surface; a light-receiving optical system configured to condense the reflected light onto the photodetector; and an optical element configured to align the optical axis of the projection optical system and the optical axis of the light-receiving optical system with each other in a range on the road surface side.

A light observation apparatus includes: a first photodetector that, upon irradiation of at least part of a physical object with irradiation light, receives first light containing ambient light and at least one selected from the group consisting of reflected light returning from the at least part and fluorescence produced from the at least part, and that outputs a first output signal representing a reception intensity of the first light; a second photodetector that receives second light containing the ambient light and outputs a second output signal representing a reception intensity of the second light; and a signal processing circuit. The signal processing circuit attenuates a first signal component corresponding to the ambient light from the first output signal based on the first output signal and the second output signal.

The embodiments disclose a method for in-situ inspection and processing of an object including providing a pulsed laser source during the in-situ inspection of a surface of the object for modifying at least one of an optical, mechanical, or chemical property of a first region of the surface, directing the laser source through an optics path to shape, position and focus a pulsed laser beam at the first region, directing a probe illumination light beam to the optics path to produce a combined and collinear optical light path of the probe illumination light beam and the pulsed laser beam to focus and deliver the combined and collinear optical light path at a same region on the surface, superimposing a first focus spot of the probe illumination light beam over a second focus spot of the pulsed laser beam on an illuminated region of the surface.

Provided are a light scattering measuring apparatus. The light scattering measuring apparatus includes: light sources; a single light receiver; a sample holder including a cell, a frame body, a first opening formed in an incident portion of a first optical path used for forward measurement or side measurement, and a second opening formed in an incident portion of a second optical path used for back measurement, and an optical element; and a moving mechanism. The first optical path and the second optical path are separated from each other in vertical direction. The moving mechanism moves the first opening to a position of the incident portion of the first optical path when the forward or side measurement is to be performed, and to move the second opening to a position of the incident portion of the second optical path when the back measurement is to be performed.

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.

An enclosure permits ingress of an infrared light beam and ultrasonic signal entering the enclosure from two different locations and facilitates their exit from the enclosure along a substantially similar egress path. The enclosure contains fluid which propagates the ultrasonic wave and a glass element which reflects the ultrasonic wave from its ingress direction onto an egress path. The fluid is an index matching fluid having a refractive index the same as the refractive index of the glass element, rendering the glass element transparent to the infrared light beam. Thus, the infrared light beam, having been induced into the enclosure on an entry path directed through the glass element, passes through the glass element without being reflected or refracted by it, placing the infrared light beam on a substantially similar path to that of the ultrasonic wave for egress of both waves from the enclosure at substantially the same point.

Improvements in spectroscopy are disclosed herein that rely on the interaction of both an infrared beam and a probe beam with a sample. These beams are used in a pump-probe arrangement, with a fiber optic probe collecting the beams of infrared and probe radiation from the infrared source and delivering it to the sample. At least a portion of the beam of infrared radiation and the beam of probe radiation overlap one another on the sample. The fiber also collects probe radiation that has interacted with the sample. A detector can use this collected signal to indicate an intensity of the collected probe radiation, and an analyzer can generate a signal indicative of infrared absorption of the sample adjacent the fiber.

A method is provided for detecting a property of a gas comprising: emitting a light, comprising a plurality of wavelengths covering a plurality of absorption lines of the gas, along a first axis, the light being scattered by particles of the gas resulting in a scattered light, generating a sensor image using a detection arrangement configured to receive the scattered light and comprising: an optical arrangement having an optical plane and being configured to direct the scattered light on to a light sensor, the light sensor having at least one pixel columns, wherein the pixel columns are aligned to an image plane and configured to output a sensor image, wherein the first axis, the optical plane, and the image plane intersect such that a Scheimpflug condition is achieved, determining, from the sensor image, properties of the gas at a plurality of positions along the first axis.

A single-shot Mueller matrix polarimeter (1700), MMP, comprising: a polarization state generator (1706), PSG, arranged to receive a source optical field (1704) and provide a probe field (1708) having a plurality of spatial portions, each portion having a different polarization state; a polarization state analyser (1718), PSA, arranged to receive a modified probe field (1716) resulting from interaction of the probe field generated by the PSG with a sample under investigation, and further arranged to apply, to each of a corresponding plurality of spatial portions of the modified probe field, a plurality of retardances and a plurality of fast axis orientations; and a detector (1720) arranged to detect an output (1722) of the PSA.