Systems and methods for filtering an optical beam are described. In one implementation, a system for filtering an input optical beam includes a first beamsplitter, a first spectral slicing module, a second spectral slicing module, and a second beamsplitter. The first beamsplitter is configured to split the input optical beam into a first optical beam and a second optical beam. The first spectral slicing module has a first passband and is configured to filter the first optical beam. The second spectral slicing module has a second passband and is configured to filter the second optical beam. The second beamsplitter is configured to combine the first optical beam and the second optical beam into an output optical beam. The first and second spectral slicing modules may each comprise a longpass filter and a shortpass filter aligned along its optical axis, and the longpass filter and/or the shortpass filter are rotatable relative to the optical axis. Advantageously, the optical system allows for tunable spectral filtering of the input optical beam suitable for 2-D imaging systems.

A typical configuration of the angle adjustment mechanism according to the present invention is provided with a parabolic mirror, a housing accommodating a parabolic mirror, a screw including a head arranged outside the housing and a shaft engaged with the parabolic mirror through a hole formed in the housing, and a base portion in contact with both the housing and the parabolic mirror. A force is applied to an engaging portion of the parabolic mirror in a direction approaching the housing and a force is applied to a portion of the parabolic mirror in contact with the base portion in a direction away from the housing. The angle of the parabolic mirror with respect to the housing changes in accordance with the change in the length of a portion where the shaft and the parabolic mirror engage.

A light radiating portion radiates light with wavelength λ1 having predetermined absorptivity for an object and light with wavelength λ2 having smaller absorptivity for the object than the wavelength λ1, to a target, so as to scan in 2-dimensional directions. A light receiving portion receives scattered lights reflected by the target based on light with wavelength λ1 and light with wavelength λ2. A measuring portion generates information used for detection of the object at the target, based on difference between the two scattered lights with wavelength λ1 and wavelength λ2 received by the light receiving portion. An output portion outputs whether or not the object is present at the target, by 2-dimensional area information, based on scanning by the light radiating portion and information generated by the measuring portion.

A method for analysing radiation emitted by the upper atmosphere, including the steps of collecting a beam coming from a direction (h, A) of the atmosphere, polarising the collected beam, selecting at least one frequency range of the collected beam and measuring an intensity of the at least one frequency range of the collected and polarised beam (I(θ,t)) according to the angle θ(t). The method includes the step of determining, from the values of I(θ,t) collected on a rotation of at least Π/2 radians of the variable angle polariser:—at least one physical and/or chemical and/or electromagnetic parameter of the upper atmosphere, and/or a variation of at least one physical and/or chemical and/or electromagnetic parameter of the upper atmosphere, and/or—a probability of malfunction and/or degradation of networks and/or electrical and/or electronic equipment and/or systems and/or devices.

A printer incorporating a spectrometry device includes a spectroscope that includes a light receiving optical system including a light receiver which receives reflected light from a range of measurement in a medium, a distance sensor that detects the distance between the medium and the spectroscope, and a reflecting mirror driver and an optical path adjuster that adjust the optical path of the reflected light which is incident on the light receiving optical system from the range of measurement according to the distance detected by the distance sensor.

An apparatus for generating a spectral image includes a filter to receive incident light. The filter has a variable refractive index. The apparatus also includes a modulator, operably coupled to the filter, to modulate the variable refractive index of the filter so as to generate a plurality of optical patterns from the incident light. The plurality of optical patterns represents the spectral image and each optical pattern in the plurality of optical patterns corresponds to a different modulation of the variable refractive index. The apparatus further includes a detector, in optical communication with the filter, to detect the plurality of optical patterns.

A tunable ultra-compact spectrometer and methods for spectrometry therefor can include a single pixel and a Fresnel zone plate having a focal length at a first temperature T.sub.1 and a first wavelength λ.sub.1, and a focal point. The pixel can be twenty micrometers square and can be placed at a distance from the pixel that equal to the focal length so that the focal point is at the pixel. The Fresnel zone plate can be made of a material that causes the same focal point at the pixel at T.sub.2, but at a different wavelength λ.sub.2 than wavelength λ.sub.1. A heat source can selectively add heat to the Fresnel zone plate to cause a second temperature T.sub.2. Exemplary materials for the Fresnel zone plate can be quartz for visible wavelengths, silicon for infrared wavelength, or other materials, according to the λ(s) of interest.

At least one light source is configured to emit at least one beam into a sample volume of an absorbing medium. In addition, at least one detector is positioned to detect at least a portion of the beam emitted by the at least one light source. Further, at least one beam modification element is positioned between the at least one detector and the at least one light source to selectively change at least one of (i) a power intensity of, or (ii) a shape of the beam emitted by the at least one light source as detected by the at least one detector. A control circuit is coupled to the beam modification element. Related apparatus methods, articles of manufacture, systems, and the like are described.

A system and method of dynamically localizing a measurement of parameter characterizing tissue sample with waves produced by spectrometric system at multiple wavelengths and detected at a fixed location of the detector of the system. The parameter is calculated based on impulse response of the sample, reference data representing characteristics of material components of the sample, and path lengths through the sample corresponding to different wavelengths. Dynamic localization is effectuated by considering different portions of a curve representing the determined parameter, and provides for the formation of a spatial map of distribution of the parameter across the sample. Additional measurement of impulse response at multiple detectors facilitates determination of change of the measured parameter across the sample as a function of time.

A compact hyperspectral imager adapted to operate in harsh environments and to conduct post acquisition signal processing to provide automated and improved hyperspectral processing results is disclosed. The processing includes luminance and brightness processing of captured hyperspectral images, hyperspectral image classification and inverse rendering to produce luminance invariance image processing.