A system for visualizing melanin present in tissue can include an imaging system to record a signal based on a presence of melanin in tissue and a display device to display an image based on the signal. A first laser source can emit a Stokes pulse train and a second laser source can emit a pump pulse train. Both the first laser source and the second laser source comprise a tunable center wavelength or frequency. An energy difference between a frequency of the Stokes pulse train and a frequency of the pump pulse train is from 1750 cm.sup.−1 to 2250 cm.sup.−1. The Stokes and the pump pulse train overlap in space and time. A scanning mechanism focuses the combined Stokes pulse train and pump pulse train within the tissue and scans across the tissue. A detector detects the signal based on a presence of melanin within the tissue.

The present disclosure is to provide a measurement chip, a measuring device, and a measuring method which can accurately estimate an analyte concentration with a simple configuration. A measurement chip may include a propagation layer, an introductory part, a drawn-out part and a reaction part. Through the propagation layer, light may propagate. The introductory part may introduce the light into the propagation layer. The drawn-out part may draw the light from the propagation layer. The reaction part may have, in a surface of the propagation layer where a reactant that reacts to a substance to be detected is formed, an area where a content of the reactant changes monotonously in a perpendicular direction perpendicular to a propagating direction of the light, over a given length in the propagating direction.

Described embodiments include a system for inspecting a tubular device that includes an outer surface and a spatially-periodic supporting structure beneath the outer surface. The system includes an imaging device, configured to acquire an image of a reflection of light from the outer surface, and a processor, configured to ascertain a spatial frequency of the supporting structure by processing the image. Other embodiments are also described.

The present disclosure is to provide a measurement chip, a measuring device, and a measuring method which can accurately estimate an analyte concentration with a simple configuration. A measurement chip may include a propagation layer, an introductory part, a drawn-out part and a reaction part. Through the propagation layer, light may propagate. The introductory part may introduce the light into the propagation layer. The drawn-out part may draw the light from the propagation layer. The reaction part may have, in a surface of the propagation layer where a reactant that reacts to a substance to be detected is formed, an area where a content of the reactant changes monotonously in a perpendicular direction perpendicular to a propagating direction of the light, over a given length in the propagating direction.

Disclosed herein are systems and methods for imaging cells. Quantitative phase imaging uses variations in the index of refraction of a sample as a source of endogenous contrast, providing label-free information of sub-cellular structures and allowing for the reconstruction of valuable biophysical parameters, such as cell dry-mass at femtogram scales, mass transport, and sample thickness and fluctuations at nanometer scales. As a result, QPI has become a valuable tool in biology and medicine. However, QPI has suffered from the need for trans-illumination through relatively thin objects in order to gain access to the forward-scattered field, which carries crucial low spatial frequency information of a sample and avoid contributions from multiple scattered light or out-of-focus planes. The disclosed methods and systems can provide for reconstruction of QPI and corresponding analysis for imaging samples of cells in thick samples using an epi-illumination configuration.

An object transfer function for a sample object is determined on the basis of a reference measurement. Subsequently, an optimization is carried out in order to find an optimized illumination geometry on the basis of the object transfer function and an optical transfer function for an optical unit.

Systems and methods for imaging cells. Quantitative phase imaging uses variations in the index of refraction of a sample as a source of endogenous contrast, providing label-free information of sub-cellular structures and allowing for the reconstruction of valuable biophysical parameters, such as cell dry-mass at femtogram scales, mass transport, and sample thickness and fluctuations at nanometer scales. As a result, QPI has become a valuable tool in biology and medicine. However, QPI has suffered from the need for trans-illumination through relatively thin objects in order to gain access to the forward-scattered field, which carries crucial low spatial frequency information of a sample and avoid contributions from multiple scattered light or out-of-focus planes. The disclosed methods and systems can provide for reconstruction of QPI and corresponding analysis for imaging samples of cells in thick samples using an epi-illumination configuration.

A detector system for spatially resolved detection of a gas substance in an area is described. The detector system includes a detector comprising an image sensor; a band filter arranged in an optical beam path before the detector for transferring a beam with a wavelength spectrum including an absorption wavelength corresponding to the gas substance, a telescope, a polarizing beam splitter, and an interferometric stage including a retarder for creating an optical path difference for measuring absorption dips due to the presence of the gas substance. The retarder includes multiple birefringent media arranged with the optical axes relative to each other so that at least one increases an optical path difference and at least one decreases an optical path difference between the polarized beam components, and the thicknesses of the birefringent media are tuned to minimize a focal shift between the polarized beam components.

A concentration measurement method for measuring a concentration of impurities includes a step of irradiating a DUT 10 serving as a measurement target object with measurement light and stimulus light subjected to intensity modulation using a modulation signal including a default frequency, a step of outputting a detection signal by detecting an intensity of reflected light from the DUT 10 or transmitted light through the DUT 10, and a step of detecting a phase delay of the detection signal with respect to the modulation signal, obtaining a frequency at which the phase delay has a predetermined value, and estimating a concentration of impurities in the measurement target object on the basis of the frequency.

Disclosed herein are systems and methods for imaging cells. Quantitative phase imaging uses variations in the index of refraction of a sample as a source of endogenous contrast, providing label-free information of sub-cellular structures and allowing for the reconstruction of valuable biophysical parameters, such as cell dry-mass at femtogram scales, mass transport, and sample thickness and fluctuations at nanometer scales. As a result, QPI has become a valuable tool in biology and medicine. However, QPI has suffered from the need for trans-illumination through relatively thin objects in order to gain access to the forward-scattered field, which carries crucial low spatial frequency information of a sample and avoid contributions from multiple scattered light or out-of-focus planes. The disclosed methods and systems can provide for reconstruction of QPI and corresponding analysis for imaging samples of cells in thick samples using an epi-illumination configuration.