Provided are a refractive index measuring device and a refractive index measuring method. A detector (2) detects an intensity of a measuring beam transmitted through the sample. A camera (200) images a color image of the measuring beam which is dispersed into multiple colors by transmitting through the sample. A scanning processing portion (101) carries out scanning by changing an angle of receiving the measuring beam transmitted through the sample or an angle of the measuring beam incident on the sample. A wavelength specifying processing portion (102) specifies, based on the detected intensity of the detector (2) varying with the scanning by the scanning processing portion (101) and color information corresponding to a position of the measuring beam incident on the detector (2) in a color image which is imaged by the camera (200), the wavelength corresponding to each peak of the detected intensity.

An apparatus and a method for in-situ phase determination are provided. The apparatus includes a measurement chamber configured to retain a substance, and an entrance window mounted on a side of the measurement chamber. An exit window is mounted on an opposite side of the measurement chamber, and the exit window is parallel with the entrance window. The apparatus further includes a light source configured to generate an incident light beam. The incident light beam is directed to the entrance window at a non-zero angle of incidence with respect to a normal of the entrance window. The incident light beam passes through the entrance window, the measurement chamber and the exit window to form an output light beam. A detector is positioned under the exit window and configured to collect the output light beam passing through the exit window and generate measurement data.

A flow cell for differential refractive index detection. The flow cell includes a transparent body that extends from a first end to a second end along a longitudinal axis. The transparent body defines a sample prism chamber and reference prism chamber. The sample prism chamber is configured to allow fluid flow between the first and second ends of the transparent body along the longitudinal axis. The reference prism chamber is configured to receive a reference fluid. The sample and reference prism chambers each include a grating comprising a plurality of grooves extending along the longitudinal axis in the direction of fluid flow.

A dynamic light scattering apparatus includes a source configured for irradiating a sample with primary electromagnetic radiation, a detector configured for detecting secondary electromagnetic radiation generated by scattering the primary electromagnetic radiation at the sample, a refraction index determination unit including a movable optical element and configured to determine information indicative of a refraction index of the sample based on measurements of the secondary electromagnetic radiation for a plurality of different positions of the movable optical element, and a particle size determining unit configured to determine information indicative of particle size of particles in the sample by analyzing the detected secondary electromagnetic radiation and taking into account the refraction index determined by the refraction index determining unit.

A method for determining an index-of-refraction profile of an optical object, which has a cylindrical surface and a cylinder longitudinal axis, said method comprising the following method steps: (a) scanning the cylindrical surface of the object at a plurality of scanning locations by means of optical beams; (b) capturing, by means of an optical detector, a location-dependent intensity distribution of the optical beams deflected in the optical object; (c) determining the angles of deflection of the zero-order beams for each scanning location from the captured intensity distribution, comprising eliminating beam intensities, and (d) calculating the index-of-refraction profile of the object on the basis of the angle-of-deflection distribution, wherein method steps (a) and (b) are carried out with light beams having at least two different wavelengths.

An opto chip for detecting a physical parameter of a liquid sample, comprising an optical structure monolithically integrated with a substrate layer and a functional layer, wherein the substrate layer is light-transmissive and configured to have an upper surface for receiving a droplet of the liquid sample and a lower surface bonded to the functional layer; and the functional layer comprises a light-emitting region and a light-detecting region with the light-emitting region being configured to emit measurement light. The light-detecting region is configured to receive reflected light derived from the measurement light and a signal reflecting the change in intensity thereof is converted into a photocurrent signal. A viscometer and detection method operated using the same opto chip technique. The need for complex external optical calibration is thus eliminated, making the viscometer easier to operate and reducing the overall size of the device.

A device for measuring solution concentration includes housing, a catadioptric structure, an electromagnetic radiation emitter and an electromagnetic radiation detector. The housing is formed with a detecting part for receiving a solution to be detected. The catadioptric structure is received in the housing, and includes a ray entrance portion, a first total internal reflection part, a second total internal reflection part and a ray exit portion. An accommodation part corresponds to the detecting part. The emitter is disposed at one side of the ray entrance portion, and a ray sequentially passes the ray entrance portion, the detecting part, the solution to be detected, and the first total internal reflection part. Then, the ray is totally internally reflected and converged to the second total internal reflection part, and is reflected again. Finally, the ray passes the ray exit portion and is received by the detector.

A method for determining a refractive index profile of an optical object having a cylindrical surface includes: (a) scanning the surface at a first plurality of scanning locations with a pinhole aperture in a path of one or more optical beams; (b) measuring a first deflection function based detecting the optical beams after deflection by the optical object for each of the first plurality of scanning locations; (c) scanning the surface at a second plurality of scanning locations where the path of the optical beams is free of the pinhole aperture; (d) measuring a second deflection function based on detecting the optical beams after deflection by the optical object for each of the second plurality of scanning locations; (e) merging at least portions of the first and second deflection functions to obtain a composite deflection function; and (f) calculating the refractive index profile using the composite deflection function.

A method can include transmitting, from a light source, light through a fuel tank ullage, and determining, by a processing device, an amount of absorption of at least one wavelength of the transmitted light. The method can further include determining, by the processing device based on the amount of absorption of the at least one wavelength of the transmitted light, a chemical composition of the fuel tank ullage.

A device for measuring solution concentration includes housing, a catadioptric structure, an electromagnetic radiation emitter and an electromagnetic radiation detector. The housing is formed with a detecting part for receiving a solution to be detected. The catadioptric structure is received in the housing, and includes a ray entrance portion, a first total internal reflection part, a second total internal reflection part and a ray exit portion. An accommodation part corresponds to the detecting part. The emitter is disposed at one side of the ray entrance portion, and a ray sequentially passes the ray entrance portion, the detecting part, the solution to be detected, and the first total internal reflection part. Then, the ray is totally internally reflected and converged to the second total internal reflection part, and is reflected again. Finally, the ray passes the ray exit portion and is received by the detector.