Abstract:
Provided are methods and systems for concurrent imaging at multiple wavelengths. In one aspect, a hyperspectral/multispectral imaging device includes a lens configured to receive light backscattered by an object, a plurality of photo-sensors, a plurality of bandpass filters covering respective photo-sensors, where each bandpass filter is configured to allow a different respective spectral band to pass through the filter, and a plurality of beam splitters in optical communication with the lens and the photo-sensors, where each beam splitter splits the light received by the lens into a plurality of optical paths, each path configured to direct light to a corresponding photo-sensor through the bandpass filter corresponding to the respective photo-sensor.
Abstract:
A handheld moisture sensing device for use in determining the moisture content of biological material, such as animal feed. Adapted to be pressed against biological material to be analyzed, the device includes a sensor assembly, including a housing with an end structure including a grate adapted to engage the material to be examined, a near infrared (NIR) LED, an NIR light sensor, a glass mounted in the housing adjacent the light source so that light from the light source passes through the glass, a glass heater positioned adjacent the glass for heating the glass, a lens mounted in the housing adjacent the NIR sensor so that the NIR light reflected off the biological material passes through the glass and is focused by the lens onto the NIR sensor, and a controller connected to the NIR sensor and receiving a signal related to the reflected NIR light received by the NIR sensor.
Abstract:
Devices, methods, and systems for cavity-enhanced spectroscopy are described herein. One system includes an optical frequency comb (OFC) coupled to a laser source, and a cavity coupled to the OFC comprising a number of mirrors, wherein at least one of the number of mirrors is coupled to a piezo-transducer configured to alter a position of the at least one of the number of mirrors.
Abstract:
A light source for near-infrared transmission and reflection spectroscopy can be constructed from a combination of a high power blue or blue-green light emitting diode (LED) and a phosphor element based on an inorganic material. The phosphor element absorbs the LED light and, in response to the LED excitation, emits luminescence that continuously covers the 700-1050 nm range. One possible material that can be used for such a near-infrared emitting phosphor element is a single crystal rod of Ti+3 doped Sapphire. An alternative near-infrared emitting phosphor material is a disk or rectangular shaped composite of Ti+3 doped Sapphire powder embedded in a clear optical epoxy or silicone encapsulant. Such a combination of a blue LED for excitation of a phosphor element that emits in a broad wavelength band has been widely used in white LEDs where the emission is in the 400-700 nm range.
Abstract:
In one embodiment, active (continuous or intermittent) passivation may be employed to prevent interaction of sticky molecules with interfaces inside of an instrument (e.g., an infrared absorption spectrometer) and thereby improve response time. A passivation species may be continuously or intermittently applied to an inlet of the instrument while a sample gas stream is being applied. The passivation species may have a highly polar functional group that strongly binds to either water or polar groups of the interfaces, and once bound presents a non-polar group to the gas phase in order to prevent further binding of polar molecules. The instrument may be actively used to detect the sticky molecules while the passivation species is being applied.
Abstract:
The present disclosure relates more particularly to active optical fibers, amplified spontaneous emission (ASE) sources using such active optical fibers, and imaging and detection systems and methods using such ASE sources. In one aspect, the disclosure provides an active optical fiber that includes a rare earth-doped gain core configured to emit radiation at at least a peak wavelength emitted wavelength when pumped with pump radiation having a pump wavelength; a pump core surrounding the gain core; and a cladding surrounding the pump core, wherein the value M=16R2(NA)2/λ2 in which R is the gain core radius, NA is the active optical fiber numerical aperture, and λ is the peak emitted wavelength, is at least 50, or at least 100. The present disclosure also provides an optical source that includes the optical fiber coupled to a pump source.
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:
A spectrometer comprises a plurality of isolated optical channels comprising a plurality of isolated optical paths. The isolated optical paths decrease cross-talk among the optical paths and allow the spectrometer to have a decreased length with increased resolution. In many embodiments, the isolated optical paths comprise isolated parallel optical paths that allow the length of the device to be decreased substantially. In many embodiments, each isolated optical path extends from a filter of a filter array, through a lens of a lens array, through a channel of a support array, to a region of a sensor array. Each region of the sensor array comprises a plurality of sensor elements in which a location of the sensor element corresponds to the wavelength of light received based on an angle of light received at the location, the focal length of the lens and the central wavelength of the filter.
Abstract:
A method and analyser for identifying or verifying or otherwise characterising a sample comprising: using or having an electromagnetic radiation source for emitting electromagnetic radiation in at least one beam at a sample, the electromagnetic radiation comprising at least two different wavelengths, using or having a sample detector that detects affected electromagnetic radiation resulting from the emitted electromagnetic radiation affected by the sample and provides output representing the detected affected radiation, and using or having a processor for determining sample coefficients from the output, and identifying or verifying or otherwise characterising the sample using the sample coefficients and training coefficients determined from training samples, wherein the coefficients reduce sensitivity to a sample retainer variation and/or are independent of concentration.
Abstract:
A terahertz spectrometer includes: a terahertz-wave emitter and a terahertz receiver elements. The terahertz wave generated by means of generating beat frequency corresponding to the difference between two rapidly tunable continuous wave lasers. Having a difference in time between the interrogating signal and the reference signal at the receiver end side, which corresponds to intermediate frequency (IF), not centered around the baseband, i.e. zero Hertz. The offset step size of the intermediate frequency from zero Hertz is linearly correlated to the position of the interrogated object position.