A lens device and an imaging apparatus that can emit illumination light coaxial with a lens optical system are proposed herein. A lens device includes an optical system that includes a first lens and a second lens forming an optical image of a subject; a first optical member that includes a frame that includes a plurality of aperture regions, a plurality of optical filters that include two or more optical filters transmitting lights having at least some wavelength ranges different from each other, and a plurality of polarizing filters that have different polarization directions; and a second optical member that is provided outside the optical system and closer to a subject side than the first optical member and emits illumination light, which is incident from the outside of the optical system, to the subject side via the optical system.

There are provided a lens device, an imaging apparatus, and an imaging method that suppress the occurrence of overexposure by dimming or blocking totally reflected light. The lens device (100) includes: an optical system (100A); a wavelength polarizing filter unit (130) that is disposed at a pupil position of the optical system (100A) or near the pupil position and includes a plurality of aperture regions, a plurality of optical filters that are disposed in the plurality of aperture regions and include two or more optical filters transmitting lights having a part of wavelength ranges different from each other, and a plurality of first polarizing filters that are disposed in the plurality of aperture regions and are at least two first polarizing filters having polarization directions different from each other; and a first circularly polarizing optical element (101) that is provided between a subject and the wavelength polarizing filter unit.

Modulation-encoded light, using different spectral bin coded light components, can illuminate a stationary or moving (relative) target object or scene. Response signal processing can use information about the respective different time-varying modulation functions, to decode to recover information about a respective response parameter affected by the target object or scene. Electrical or optical modulation encoding can be used. LED-based spectroscopic analysis of a composition of a target (e.g., SpO2, glucose, etc.) can be performed; such can optionally include decoding of encoded optical modulation functions. Baffles or apertures or optics can be used, such as to constrain light provided by particular LEDs. Coded light illumination can be used with a focal plane array light imager receiving response light for inspecting a moving semiconductor or other target. Encoding can use orthogonal functions, such as an RGB illumination sequence, or a sequence of combinations of spectrally contiguous or non-contiguous colors.

The invention provides methods and apparatus comprising a multi-wavelength laser source that uses a single unfocused pulse of a low intensity but high power laser over a large sample area to collect Raman scattered collimated light, which is then Rayleigh filtered and focused using a singlet lens into a stacked fiber bundle connected to a customized spectrograph, which separates the individual spectra from the scattered wavelengths using a hybrid diffraction grating for collection onto spectra-specific sections of an array photodetector to measure spectral intensity and thereby identify one or more compounds in the sample.

The present disclosure provides for an apparatus for measuring optical properties of liquid samples. The apparatus includes a sample chamber and a spectrometer optically coupled with the sample chamber. One or multiple sources of electromagnetic radiation are positioned relative to the sample chamber to direct electromagnetic radiation through the sample chamber to measure the color, haze, and/or clarity of the sample. Also provided is a method for measuring optical properties of liquid samples, including inserting a cuvette containing a liquid sample into the sample chamber of the apparatus, and directing electromagnetic radiation from the one or more sources and through the sample to measure the color, haze, and/or clarity of the sample. The apparatus and methods may be used to analyze various samples, such as petroleum-based fluids, including fuels and lubricants.

Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

A meteorological lidar performs highly precise meteorological observation by primarily removing elastically scattered light and by detecting rotational Raman-scattered light without filtering it out. The meteorological lidar according to embodiments measures scattered light of a laser beam, and includes: a diffraction grating diffracting rotational Raman-scattered light contained in scattered light in accordance with the wavelength of rotational Raman-scattered light; a detector detecting the diffracted rotational Raman-scattered light; and a removing element primarily removing elastically scattered light of a specific wavelength contained in the scattered light.

A method for retrieving a corrected spectrum from a measured spectrum (e.g., retrieving a top-of-water spectrum from a measured top-of-atmosphere spectrum) includes creating a scene-specific model of a region of interest and performing a ray-tracing simulation to simulate rays of light that would reach an airborne (or spaceborne) sensor. The region of interest can be an optically complex area such as an inland or coastal body of water. Based on the ray-tracing simulation, a scene-specific correction for unwanted effects (e.g., adjacency effects, variable atmospheric conditions, and/or other suitable effects) is obtained. A corrected spectrum is obtained by correcting the measured spectrum using the scene-specific correction. The ray-tracing simulation may be performed using a graphical processing unit, allowing the scene-specific correction to be performed in real time or near real time.

A spectroscopic measurement apparatus includes an optical system, a photodetector, and an analysis unit. The optical system guides measurement target light from an object to a light receiving surface of the photodetector, and forms a spectral image of the measurement target light on the light receiving. The photodetector includes the light receiving surface on which a plurality of pixels are arranged respectively on a plurality of rows. The photodetector receives the spectral image for a first exposure time by a plurality of pixels in a first region on the light receiving surface, and outputs first spectrum data. The photodetector receives the spectral image for a second exposure time by a plurality of pixels in a second region on the light receiving surface, and outputs second spectrum data. The second exposure time is longer than the first exposure time.

A hyperspectral camera based on a continuously variable film filter and a coating method thereof can solve interference between partial bands of the hyperspectral camera based on the continuously variable film filter. The hyperspectral camera includes: a camera body and a detector chip, wherein a continuously variable film is coated on the detector chip; a semi-transmission half-cut filter is provided in front of the continuously variable film, and a distance between the semi-transmission half-cut filter and the continuously variable film is 0 mm. According to the present invention, the semi-transparent half-cut filter and the detector chip are integrated without any gap therebetween. As a result, optical interference caused by incident light sequentially passing through the semi-transparent half-cut filter and the detector chip is greatly reduced, which can reduce distortion of spectral signals, and finally satisfy wide-band application requirements which can be truly realized based on such technology.