A system and method are described for performing tear film structure measurement. A broadband light source illuminates the tear film. A spectrometer measures respective spectra of reflected light from at least one point of the tear film. A color camera performs large field of view imaging of the tear film, so as to obtain color information for all points of the tear film imaged by the color camera. A processing unit calibrates the camera at the point measured by the spectrometer so that the color obtained by the camera at the point matches the color of the spectrometer at the same point. The processing unit determines, from the color of respective points of the calibrated camera, thicknesses of one or more layers of the tear film at the respective points. Other applications are also described.

Gas detection apparatus for the detection of a target gas in a gas mixture, having a radiation source, a first measurement chamber and a second measurement chamber, as well as a first and second measurement detector. A first gas mixture flows through the first measurement chamber, and a second gas mixture flows through the second measurement chamber. Electromagnetic radiation emitted by the radiation source passes initially through the first measurement chamber and subsequently through the second measurement chamber. The first measurement detector registers a physical effect in the first measurement chamber, this physical effect correlating with the intensity of the radiation passing through the first measurement chamber, and generates a first signal correlating with the physical effect. The second measurement detector is correspondingly configured for the second measurement chamber. A second measurement point is thus provided without requiring a second radiation source.

A device for optical detection of analytes in a sample includes at least two optoelectronic components. The optoelectronic components include at least one optical detector configured to receive a photon and at least one optical emitter configured to emit a photon. The at least one optical emitter includes at least three optical emitters disposed in a flat, non-linear arrangement, and the at least one optical detector includes at least three optical detectors disposed in a flat, non-linear arrangement. The at least three optical emitters and the at least three optical detectors include at least three different wavelength characteristics.

A measuring device is provided for measuring the absorption of gases. The measuring device (1) includes a radiation source (2), a first detector element (3), a second detector element (9) and a reflector array (4). The reflector array (4) defines a first optical path (5) between the radiation source (2) and the first detector element (3) and defines a second optical path (10) between the radiation source (2) and the second detector element (9). The first optical path (5) has at least two points of intersection with itself and the second detector element (9) is arranged outside of a first plane which is defined by the radiation source (2) and two points of intersection (6) of the first optical path (5).

A microfluidic apparatus is provided. The microfluidic apparatus includes a first substrate; a microfluidic layer on the first substrate and defining a microfluidic channel, wherein the first substrate having a first side closer to the microfluidic layer, and a second side away from the microfluidic layer, the first side and the second side opposite each other; a plurality of detectors on a side of the microfluidic channel away from the first substrate; a unitary grating plate on the second side of the first substrate and including a plurality of grating blocks of different wavelength selectivity; and a light extraction layer including a plurality of light extractors on the first side of the first substrate and configured to extract light diffracted by the plurality of grating blocks out of the first substrate.

Described here are optical sampling architectures and methods for operation thereof. An optical sampling architecture can be capable of emitting a launch sheet light beam towards a launch region and receiving a detection sheet light beam from a detection region. The launchregion can have one dimension that is elongated relative to another dimension. The detection region can also have one dimension elongated relative to another dimension such that the system can selectively accept light having one or more properties (e.g., angle of incidence, beam size, beam shape, etc.). In some examples, the elongated dimension of the detection region can be greater than the elongated dimension of the launch region. In some examples, the system can include an outcoupler array and associated components for creating a launch sheet light beam having light rays with different in-plane launch positions and/or in-plane launch angles.

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.

Embodiments create an arrangement and a method for analyzing a fluid. The arrangement (10) for analyzing a fluid comprises beam splitter and mixer optics (12) configured to spatially mix an optical signal and split the same into at least two spatial sub-beams and a flow cell (14) configured to spectrally influence at least the two spatial sub-beams (15a; 15b) by means of a probe of the fluid. The arrangement further comprises a measurement system (16) configured to measure the at least two spatially separated sub-beams (15a; 15b).

A microfluidic apparatus is provided. The microfluidic apparatus includes a first substrate; a microfluidic layer on the first substrate and defining a microfluidic channel, wherein the first substrate having a first side closer to the microfluidic layer, and a second side away from the microfluidic layer, the first side and the second side opposite each other; a plurality of detectors on a side of the microfluidic channel away from the first substrate; a unitary grating plate on the second side of the first substrate and including a plurality of grating blocks of different wavelength selectivity; and a light extraction layer including a plurality of light extractors on the first side of the first substrate and configured to extract light diffracted by the plurality of grating blocks out of the first substrate.