Abstract:
A method for deriving a background-corrected portion of a measured optical emission spectrum comprising the steps of identifying two or more background correction points from the portion of the measured emission spectrum; deriving a background correction function fitted to the identified background correction points, and applying the background correction function to the portion of the measured emission spectrum so as to produce a background-corrected portion of the emission spectrum, wherein the background correction points are identified from the measured data points by consideration of the gradients between the measured data points.
Abstract:
A spectrometer includes a light source to project a light beam to a target object, an optical element including a plurality of apertures through which the light beam reflected by the target object transmits, a diffraction element to form diffracted images from a plurality of light beams having transmitted through the optical element, and a light receiving element to receive the diffracted images formed by the diffraction element and including an optical shield to block a diffracted image other than a certain-order diffracted image.
Abstract:
Aspects of the subject technology relate to methods and systems for identifying a target material. The system includes a tunable laser, an imaging device, and a signal processor. The tunable laser is configured to intermittently direct electromagnetic radiation of at least one selected wavelength at a surface of a target material. The imaging device is configured to capture at least one “on” image of the surface when the electromagnetic radiation of the at least one selected wavelength is directed at the surface and capture at least one “off” image of the surface when electromagnetic radiation of the at least one selected wavelength is not directed at the surface. The signal processor is configured to compare, for each selected wavelength, the “on” image(s) corresponding to the selected wavelength with the “off” image(s) corresponding to the selected wavelength and identify the target material based on the comparison.
Abstract:
A spectrometer includes a light source to project a light beam to a target object, an optical element including a plurality of apertures through which the light beam reflected by the target object transmits, a diffraction element to form diffracted images from a plurality of light beams having transmitted through the optical element, and a light receiving element to receive the diffracted images formed by the diffraction element and including an optical shield to block a diffracted image other than a certain-order diffracted image.
Abstract:
A spectroscopic measurement apparatus includes: a wavelength tunable interference filter including a fixed substrate having a fixed reflection film, a movable substrate having a movable reflection film, and an electrostatic actuator that changes a gap value of an inter-reflection-film gap by applying a voltage to bend the movable substrate; a detector that detects a light level; and a controller that measures a spectral characteristic of light under measurement. The controller includes a filter driver that applies a drive voltage to the electrostatic actuator to change the inter-reflection-film gap, a detected light level acquisition unit that acquires light levels detected by the detector, and a target light level acquisition unit that acquires a light level corresponding to an oscillation center of the movable substrate as a target light level based on how the detected light level transitions and a natural oscillation cycle that the movable substrate has.
Abstract:
A system for reducing effects relating to stretching of an optical fiber includes an optical control source, the optical source outputting an optical signal, a terahertz transmitter and receiver both being optically coupled to the optical source, and a means for providing the optical signal to both the terahertz transmitter and terahertz receiver such that the terahertz receiver is synchronized to the terahertz transmitter by the optical signal. The means prevents the stretching of an fiber carrying the optical signal provided to the terahertz transmitter or terahertz receiver or allows for the stretching an optical fiber such that the terahertz receiver will still be synchronized to the terahertz transmitter by the optical signal.
Abstract:
Remote absorption spectroscopy uses coded electromagnetic transmission directed through a medium under investigation to one or more remote receivers. The coded transmission includes at least one wavelength coincident with an absorption band of interest and one wavelength in an off-line band and a predefined relationship between spectral components in and outside the absorption band is controlled. The relationship between spectral components may be evaluated at the receiver to determine whether deviation thereof from the controlled relationship at the transmitter exists at the receiver. The deviation of the received optical signal from the prescribed relationship is processed to indicate the absorption of the radiation in the absorption band.
Abstract:
A system for reducing effects relating to stretching of an optical fiber includes an optical control source, the optical source outputting an optical signal, a terahertz transmitter and receiver both being optically coupled to the optical source, and a means for providing the optical signal to both the terahertz transmitter and terahertz receiver such that the terahertz receiver is synchronized to the terahertz transmitter by the optical signal. The means prevents the stretching of an fiber carrying the optical signal provided to the terahertz transmitter or terahertz receiver or allows for the stretching an optical fiber such that the terahertz receiver will still be synchronized to the terahertz transmitter by the optical signal.
Abstract:
Methods in a spectral measurement apparatus are disclosed. Light is received with a plurality of sensors. Each sensor generates an output signal having a frequency proportional to an intensity of light received by the sensor. First, second and third signals are generated each having a frequency proportional to an intensity of light received by a sensor of a wavelength or spectral band. A spectral characteristic of the received light is determined based on at least the first, second and third signals, which are are coupled to a processing element and input in parallel. The spectral characteristic is determined based on measuring a frequency or period of the at least first, second and third signals. Spectral data based on the determined spectral characteristic is generated by the processing element and displayed on a display device for perception by a viewer or transmitted to a data interface for transmission to an electronic device external to the spectral measurement apparatus.
Abstract:
A colour measuring unit (1) comprising a radiation device (2) which emits light onto a surface (9) to be examined, wherein the radiation device (2) comprises at least one semiconductor-based light source (6), and a radiation detector device (12) which receives at least a portion of the light scattered by the surface and outputs a signal characteristic of this light, wherein the radiation detector device (12) allows a spectral analysis of the light impinging thereon. According to the invention, the colour measuring unit comprises at least one sensor device (10) which determines at least one electrical parameter of the light source (6), and also a processor device (14) which outputs from this measured parameter at least one value characteristic of the light emitted by the radiation device (2).