Abstract:
A device for detecting electromagnetic radiation comprises a waveguide and at least one resonator on a substrate, and a low-refractive index region between each resonator and the substrate. The low-refractive index region has a lower refractive index than a material of the resonator. The low-refractive index region may be annular, and may have a width corresponding to a width of a region in which electromagnetic radiation is concentrated in a whispering-gallery resonant mode. The low-refractive index region may be an air gap between the substrate and the resonator. The device may be a spectrometer for detecting a plurality of predetermined wavelengths of electromagnetic radiation.
Abstract:
A method of optical spectroscopy and a device for use in optical spectroscopy. The device includes a substrate, and a plurality of etalon cavities affixed to or coupled to the substrate. A signal is received from a Fabry-Perot interferometer. The signal is sampled using the device according to a generalized Nyquist-Shannon sampling criterion. The signal is sampled using the device according to a phase differential criterion for wave number resolution. An input spectrum for the signal is reconstructed based on the signal sampled according to the generalized Nyquist-Shannon sampling criterion and the signal sampled according to the phase differential criterion for wave number resolution.
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 spectroscopic analysis apparatus includes a light source section that radiates light toward an object being imaged, an imaging section that captures light reflected off the object being imaged to acquire an image, a pixel detector that detects an abnormal pixel in the image which is a pixel where a reflectance ratio is greater than or equal to 1 and detects normal pixels in the image each of which is a pixel where the reflectance ratio is smaller than 1, and a light amount corrector that calculates a light amount correction value based on the amounts of light at normal pixels in a pixel area including the abnormal pixel in the image and replaces the amount of light at the abnormal pixel with the light amount correction value.
Abstract:
An Etalon filter includes a first substrate, a second substrate which faces the first substrate, a first optical film which is provided on the first substrate, and a second optical film which is provided on the second substrate to face the first optical film. The reflective characteristic of the first optical film determined by the reflectance of light of each wavelength in a reflective band is different from the reflective characteristic of the second optical film determined by the reflectance of light of each wavelength in the reflective band. The first optical film can have a reflective characteristic with a first wavelength λ1 as a center wavelength, and the second optical film can have a reflective characteristic with a second wavelength λ2 different from the first wavelength as a center wavelength.
Abstract:
A spectroscopic measurement apparatus includes a fixed substrate, a movable substrate, and a wavelength variable interference filter which includes an electrostatic actuator for changing the gap dimension between the substrates, a vibration disturbance detection unit which detects vibration added to the wavelength variable interference filter, and a bias driving unit which applies a feed-forward voltage based on a detected value of the vibration disturbance detection unit to the electrostatic actuator.
Abstract:
An optical module includes a wavelength variable interference filter that selects light of a predetermined wavelength from incident light, and can change the wavelength of emitted light; a global shutter imaging element that accumulates electric charges while being exposed to the emitted light, and outputs a detection signal in response to the accumulated electric charges; an imaging element controller for setting a photodetection period during which the electric charges are accumulated in the imaging element, and a standby period during which the electric charges accumulated in the imaging elements are reset; and a spectroscopic controller for controlling the wavelength change driving of the emitted light. The imaging element controller sets the duration of the standby period to a minimum drive time for changing the wavelength or greater. The spectroscopic controller starts the wavelength change driving at the start of the standby period.
Abstract:
A system for remotely sensing a target material in situ include a broad-band laser source, at least one tunable filter coupled to the source laser for generating a swept-frequency signal an optical device for splitting the swept-frequency signal into a first illumination signal and second illumination signal, a first optical path for directing the first illumination signal unto the target material and receiving a reflected signal from the target material, a second optical path for receiving the second illumination signal and generating a spectral reference signal, and a controller coupled to the first optical path and the second optical path for adjusting the frequency and spatial resolution of the laser source based at least in part on a comparison of the spectral reference signal and the reflected signal.
Abstract:
A wavelength-tunable interference filter comprising a first substrate, a second substrate facing the first substrate, a first reflective film provided on the first substrate, a second reflective film provided on the second substrate, the second reflective film facing the first reflective film, a first electrode provided on the first substrate, and a second electrode provided on the second substrate, the second electrode facing the first electrode, wherein the first electrode includes a first electrode layer and a second electrode layer, the first electrode layer has a first in-plane internal stress which is compressive, and the second electrode layer has a second in-plane internal stress which is tensile.
Abstract:
A system includes a downhole formation fluid sampling tool and a processor. An optical spectrometer of the downhole formation fluid sampling tool is able to measure an optical characteristic of a formation fluid flowing through the downhole formation fluid sampling tool over a plurality of wavelengths. The optical spectrometer generates optical spectra data indicative of this optical characteristic. The processor is designed to receive the optical spectra data generated by the optical spectrometer and to estimate a formation volume factor of the formation fluid based on the optical spectra data.