A method of determining a phase shift caused by reflection at, or transmission through, a dielectric coating as a function of wavenumber includes obtaining a nominal phase shift for the dielectric coating as a function of wavenumber, determining a first wavenumber and a second wavenumber for performing measurements of phase shift at these wavenumbers based on the nominal phase shift, determining a wavenumber shift based on a first measurement of phase shift at the first wavenumber, a second measurement of phase shift at the second wavenumber, and the nominal phase shift as a function of wavenumber, and determining the phase shift as a function of wavenumber based on the wavenumber shift and the nominal phase. Further described is a method of determining a layer design for a dielectric coating, wherein the dielectric coating comprises a plurality of stacked layers.

Methods and apparatus for examining a material are provided. One example method generally includes disposing the material in a dielectric contrast analysis structure, wherein the dielectric contrast analysis structure comprises a bulk dielectric substance and a plurality of receptacles in the bulk dielectric substance, wherein the material is disposed in one or more of the plurality of receptacles; exposing the dielectric contrast analysis structure to incident electromagnetic radiation; detecting resultant radiation from the exposed dielectric contrast analysis structure; and analyzing the detected resultant radiation to estimate at least one of a phase fraction and a phase distribution in the material. One example system generally includes an electromagnetic radiation source; a dielectric contrast analysis structure comprising a bulk dielectric substance and a plurality of receptacles in the bulk dielectric substance for receiving the material; and an electromagnetic radiation detector, wherein the analysis structure is between the radiation source and the detector.

Proposed are a three-dimensional (3D) optical tomography method and apparatus using a partially coherent light and a multi-illumination pattern. The 3D optical diffraction tomography method based on low coherence light and a multi-illumination pattern using a 3D optical diffraction tomography apparatus may include making light incident on a sample using a plurality of patterns, measuring, by an image measurement unit, different locations at different depth locations of the sample and measuring two-dimensional (2D) images of the sample, and reconstructing 3D refractive index information of the sample based on the different patterns and the 2D images obtained at the different depth locations.

Systems for examining a material comprising: an electromagnetic radiation source; a dielectric contrast analysis structure comprising: a bulk dielectric substance; a plurality of receptacles in the bulk dielectric substance for receiving the material; and an electromagnetic radiation detector, wherein the dielectric contrast analysis structure is between the electromagnetic radiation source and the electromagnetic radiation detector. Wherein the plurality of receptacles are substantially parallel with one another and are disposed in a dielectric contrast analysis structure that is disposed in a pipe. Wherein the dielectric contrast analysis structure comprises: a bulk dielectric substance having a first end, a second end, and the plurality of receptacles disposed within the bulk dielectric substance, wherein a flow path of the material through the receptacles is from the first end of the bulk dielectric substance to the second end of the bulk dielectric substance.

An observation apparatus includes a light source, a mirror, a condenser lens, an objective lens, a beam splitter, an imaging unit, and an analysis unit. The analysis unit includes an interference intensity image acquisition unit, a first complex amplitude image generation unit, a second complex amplitude image generation unit, a two-dimensional phase image generation unit, a three-dimensional phase image generation unit, and a refractive index distribution calculation unit. The analysis unit irradiates an observation object with light along each of a plurality of light irradiation directions, acquires an interference intensity image at a reference position for each of the plurality of light irradiation directions from the imaging unit, and performs necessary processing based on the interference intensity images to obtain a three-dimensional refractive index distribution of the observation object.

Proposed are a three-dimensional (3D) optical tomography method and apparatus using a partially coherent light and a multi-illumination pattern. The 3D optical diffraction tomography method based on low coherence light and a multi-illumination pattern using a 3D optical diffraction tomography apparatus may include making light incident on a sample using a plurality of patterns, measuring, by an image measurement unit, different locations at different depth locations of the sample and measuring two-dimensional (2D) images of the sample, and reconstructing 3D refractive index information of the sample based on the different patterns and the 2D images obtained at the different depth locations.

A method is provided that allows the sulfur component concentration in gasoline to be estimated to high precision. The measuring method of the disclosure is a method of measuring the concentration of sulfur components in gasoline that contains sulfur components and aromatic components. The measuring method of the disclosure comprises: (A1) removing a portion of the gasoline by gasification to lower the proportion of the aromatic component concentration with respect to the sulfur component concentration in the gasoline, (A2) measuring values related to the refractive index of the gasoline, and (A3) measuring the sulfur component concentration in the gasoline based on the values related to the refractive index.

An imaging device for a microscope includes an optical imaging system configured to form at least two optical images of an object in at least two different focusing states, and a processor configured to process image information from the at least two optical images in order to obtain phase information that is characteristic of the object being imaged. The optical imaging system comprises an image sensor module having at least two image sensors each being associated with a respective one of the at least two different focusing states. The at least two image sensors are configured to simultaneously detect the at least two optical images for generating the image information. The image sensor module comprises an adjustable aperture element which is controllable by the processor.

A deformometer includes: a cavity body; entry and exit optical cavity optics, such that the optical cavity produces filtered combined light from combined light; a first laser that provides first light; a second laser that provides second light; an optical combiner that: receives the first light; receives the second light; combines the first light and the second light; produces combined light from the first light and the second light; and communicates the combined light to the entry optical cavity optic; a beam splitter that: receives the filtered combined light; splits the filtered combined light; a first light detector in optical communication with the beam splitter and that: receives the first filtered light from the beam splitter; and produces a first cavity signal from the first filtered light; and a second light detector that: receives the second filtered light; and produces a second cavity signal from the second filtered light.

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.