Abstract:
An active remote sensing system is provided with an array of laser diodes that generate light directed to an object having one or more optical wavelengths that include at least one near-infrared wavelength between 700 nanometers and 2500 nanometers. One of the laser diodes pulses with pulse duration of approximately 0.5 to 2 nanoseconds at repetition rate between one kilohertz and about 100 megahertz. A beam splitter receives the laser light, separates the light into a plurality of spatially separated lights and directs the lights to the object. A detection system includes a photodiode array synchronized to the array of laser diodes and performs a time-of-flight measurement by measuring a temporal distribution of photons received from the object. The time-of-flight measurement is combined with images from a camera system, and the remote sensing system is configured to be coupled to a wearable device, a smart phone or a tablet.
Abstract:
An imaging system (200) for generating a measure of authenticity of an object (10) comprises a dispersive imaging arrangement (30) and an image sensor arrangement (60). They are positioned so that, when electromagnetic radiation (20) from the object (10) illuminates the dispersive imaging arrangement (30), the electromagnetic radiation is dispersed and imaged by the image sensor arrangement (60). The imaging system (200) is configured to then generate a measure of authenticity of the object (10) depending at least on a relation between the imaged dispersed electromagnetic radiation and reference spectral information. The invention also relates to imaging methods, computer programs, computer program products, and storage mediums.
Abstract:
A wearable device includes a measurement device adapted to be placed on a wrist or ear having a light source with LEDs to measure physiological parameters. The measurement device generates an optical beam having a near infrared wavelength between 700-2500 nanometers by modulating the LEDs, and lenses to deliver the beam to tissue, which reflects the beam to a receiver having spectral filters in front of spatially separated detectors coupled to analog to digital converters that generate at least two receiver outputs. Signal-to-noise ratio of the beam reflected from the tissue is improved by comparing the receiver outputs, and by increasing light intensity from the LEDs. The receiver is synchronized to the modulation of the LEDs and uses a lock-in technique that detects the modulation frequency. The measurement device generates an output signal representing a non-invasive measurement on blood within the tissue.
Abstract:
In a color imaging system, multiple rendering devices are provided at different nodes along a network. Each rendering device has a color measurement instrument for calibrating the color presented by the rendering device. A rendering device may be a printer in which the measuring of color samples on a sheet rendered by the printer is provided by a sensor coupled to a transport mechanism which moves the sensor and sheet relative to each other, where the sensor provides light from the samples to a spectrograph. A rendering device may also be a display having a member supporting a color measuring instrument for receiving light from an area of the screen. The color measuring instruments provide for non-contact measurements of color samples rendered on a display or a sheet, and are self-calibrating by the use of calibration references.
Abstract:
A device and method for surface height profiling are presented. The device has a source with a source slit through which light is provided. The device includes an objective lens having a reference surface. The objective lens is configured to illuminate a sample with test light from the source and to combine test light reflected from the sample with reference light reflected from the reference surface to form combined light. A spectrometer is positioned to receive the combined light at an entrance slit. The spectrometer is configured to image the combined light as a 2D image with a wavelength dimension and a spatial position dimension. A processor in electrical communication with the spectrometer is programmed to receive a signal representing the 2D image and to determine a surface height profile of the sample based on the signal.
Abstract:
The subject matter described herein includes a curved VPH grating with tilted fringes and spectrographs, both retroreflective and transmissive, that use such gratings. A VPH grating according to the subject matter described herein includes a first curved surface for receiving light to be diffracted. The grating includes an interior region having tilted fringes to diffract light that passes through the first surface. The grating further includes a second curved surface bounding the interior region on a side opposite the first surface and for passing light diffracted by the fringes.
Abstract:
A sensor unit (100) provided with a substrate (101), a plurality of light-receiving units (102) that are provided on the substrate (101) and detect light, and a diffraction grating layer (103) that is provided on the substrate (101) and the light-receiving units (102) and has at least two diffraction means for diffracting light of corresponding wavelengths and condensing the light onto the light-receiving units, wherein at least two of the diffraction means are composed from holograms formed on a first diffraction grating layer and at least a portion of the plurality of holograms formed on the first diffraction grating layer overlap at least partially with another adjacent hologram.
Abstract:
A system and method for using near-infrared or short-wave infrared (SWIR) sources such as lamps, thermal sources, LED's, laser diodes, super-luminescent laser diodes, and super-continuum light sources for early detection of dental caries measure transmission and/or reflectance. In the SWIR wavelength range, solid, intact teeth may have a low reflectance or high transmission with very few spectral features while a carious region exhibits more scattering, so the reflectance increases in amplitude. The spectral dependence of the transmitted or reflected light from the tooth may be used to detect and quantify the degree of caries. Instruments for applying SWIR light to one or more teeth may include a C-clamp design, a mouth guard design, or hand-held devices that may augment other dental tools. The measurement device may communicate with a smart phone or tablet, which may transmit a related signal to the cloud, where additional value-added services are performed.
Abstract:
In a color imaging system, multiple rendering devices are provided at different nodes along a network. Each rendering device has a color measurement instrument for calibrating the color presented by the rendering device. A rendering device may be a printer in which the measuring of color samples on a sheet rendered by the printer is provided by a sensor coupled to a transport mechanism which moves the sensor and sheet relative to each other, where the sensor provides light from the sample to a spectrograph. A rendering device may also be a display having a member supporting a color measuring instrument for receiving light from an area of the screen. The color measuring instruments provide for non-contact measurements of color samples rendered on a display or a sheet, and are self-calibrating by the use of calibration references.
Abstract:
A system and method for using near-infrared or short-wave infrared (SWIR) light sources between approximately 1.4-1.8 microns, 2-2.5 microns, 1.4-2.4 microns, 1-1.8 microns for active remote sensing or hyper-spectral imaging for detection of natural gas leaks or exploration sense the presence of hydro-carbon gases such as methane and ethane. Most hydro-carbons (gases, liquids and solids) exhibit spectral features in the SWIR, which may also coincide with atmospheric transmission windows (e.g., approximately 1.4-1.8 microns or 2-2.5 microns). Active remote sensing or hyper-spectral imaging systems may include a fiber-based super-continuum laser and a detection system and may reside on an aircraft, vehicle, handheld, or stationary platform. Super-continuum sources may emit light in the near-infrared or SWIR. An imaging spectrometer or a gas-filter correlation radiometer may be used to identify substances or materials such as oil spills, geology and mineralogy, vegetation, greenhouse gases, construction materials, plastics, explosives, fertilizers, paints, or drugs.