Abstract:
A spectral instrument including a light source configured to produce a light beam, the light beam comprising a plurality of wavelengths, and the light beam being about collimated or pseudo-collimated. The spectral instrument also includes a spectral dispersion device in optical communication with the light source. The spectral instrument also includes a screen disposed in the optical path after the spectral dispersion device. The screen comprises a material configured to be substantially opaque to at least some of the plurality of wavelengths. The screen is sized and dimensioned to at least partially block selected ones of the plurality of wavelengths. The screen is movable with respect to an axis of the screen. The spectral instrument also includes an imaging lens disposed in the optical path and disposed either after the screen or before the screen.
Abstract:
Wavenumber linear spectrometers are provided including an input configured to receive electromagnetic radiation from an external source; collimating optics configured to collimate the received electromagnetic radiation; a dispersive assembly including first and second diffractive gratings, wherein the first diffraction grating is configured in a first dispersive stage to receive the collimated electromagnetic radiation and wherein the dispersive assembly includes at least two dispersive stages configured to disperse the collimated input; and an imaging lens assembly configured to image the electromagnetic radiation dispersed by the at least two dispersive stages onto a linear detection array such that the variation in frequency spacing along the linear detection array is no greater than about 10%.
Abstract:
A liquid fuel property detection apparatus includes a fuel passage, a light emitting device for emitting a light including a plurality of predetermined wavelengths toward the fuel in the passage, a light receiving device for receiving the light passing through the fuel, and a calculation unit for calculating the concentration of at least one of aroma, paraffin and olefin, which are hydrocarbon component components contained in the fuel. The calculation unit calculates the concentration of a specific component, which is one of aroma, paraffin and olefin, based on the reference transmittance of light in the specific component and the actual transmittance calculated from the amount of light emitted by the light emitting device and the amount of light received by the light receiving device with respect to each wavelength of the light.
Abstract:
A mechanism for bandwidth selection includes a dispersive optical element having a body including a reflective face of dispersion including an area of incidence extending in a longitudinal axis direction along the reflective face of the dispersive optical element. The body also includes a first end block, disposed at a first longitudinal end of the body and a second end block, disposed at a second longitudinal end of the body, the second longitudinal end being opposite the first longitudinal end. The bandwidth selection mechanism also includes a first actuator mounted on a second face of the dispersive optical element, the second face being opposite from the reflective face, the first actuator having a first end coupled to the first end block and a second end coupled to the second end block, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body and in a first direction normal to the reflective face of the dispersive optical element. The bandwidth selection mechanism also includes a second actuator mounted on a third face of the dispersive optical element, the third face being normal to the reflective face, the second actuator having a first end coupled to the first end block with a first flexture and a second end coupled to the second end block with a second flexture, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element, the second direction also being perpendicular to the first direction the second actuator including a pressurized fluid force application mechanism. A method of selecting bandwidth is also disclosed.
Abstract:
A spectroanalytical system includes entrance aperture defining structure for receiving radiation to be analyzed along a first path; collimating structure in the first path for providing collimated radiation along a second path; fixed refraction structure in the second path for spatially separating (refracting) radiation in the second path in a first direction as a function of wavelength; fixed echelle grating structure in the second path for spatially separating the refracted radiation as a function of wavelength in a second direction orthogonal to the first direction and directing the orthogonally dispersed radiation in a beam along a third path that does not pass through the first refraction structure; and two-dimensional array detector structure for detecting the beam of orthogonally refracted radiation.
Abstract:
A remote sensing system for time-of-flight measurements may comprise an array of laser diodes with Bragg reflectors operating in the near-infrared wavelength range synchronized to a detection system comprising lenses, spectral filters and a photodiode array coupled to a processor. The time-of-flight depth information may be combined with various camera imaging systems. The camera system may comprise a lens system, prism and a sensor. In another embodiment, the data from two cameras may be combined with the time-of-flight depth information. Yet another embodiment comprises an imaging system with another array of laser diodes followed by a beam splitter and a detection system. The remote sensing system may be coupled to a smart phone, tablet or wearable device, and the combined data may provide three-dimensional information about at least some part of an object. Also, artificial intelligence may be used in the processing to make decisions regarding the depth and images.
Abstract:
A sensing system includes laser diodes with Bragg reflectors generating light having an initial light intensity and one or more near-infrared optical wavelengths. The laser diodes are modulated with a pulsed output with 0.5 to 2 nanosecond pulse duration. A beam splitter receives light from the laser diodes, splits the light into a received sample arm light directed to an object and a received reference arm light. A detection system includes a second lens and spectral filters in front of a photodiode array. The photodiode array is coupled to CMOS transistors and receives at least a portion of the received reference arm light and generates a reference detector signal. The detection system is synchronized with the laser diodes. A time-of-flight measurement is based on a comparison of the sample detector signal and the reference detector signal and measures a temporal distribution of photons in the received reflected sample arm light.
Abstract:
An optical device may include a dispersion element. The optical device may include a reflective optic to reflect an optical beam with a fixed offset perpendicular to a dispersion direction of the dispersion element and with a negative offset in the dispersion direction of the dispersion element. The reflective optic may be aligned to the dispersion element to offset an optical beam with respect to the dispersion element and to cause the optical beam to pass through the dispersion element on a plurality of passes, offsetting the optical beam on each of the plurality of passes.
Abstract:
An optical system operating in the near or short-wave infrared wavelength range identifies an object based on water absorption. The system comprises a light source with modulated light emitting diodes operating at wavelengths near 1090 and 1440 nanometers, corresponding to lower and higher water absorption. The system further comprises one or more wavelength selective filters and a housing that is further coupled to an electrical circuit and a processor. The detection system comprises photodetectors that are synchronized to the light source, and the detection system receives at least a portion of light reflected from the object. The system is configured to identify the object by comparing the reflected light at the first and second wavelength to generate an output value, and then comparing the output value to a threshold. The optical system may be further coupled to a wearable device or a remote sensing system with a time-of-flight sensor.
Abstract:
An imaging device includes laser diodes (LDs) generating near-infrared wavelength light, lenses configured to deliver the light to tissue, a first receiver having one or more detectors, and a first part with at least one of the LDs capable of being pulsed. The first receiver receives light reflected from the tissue and is synchronized to the pulsed light and configured to perform a time-of-flight measurement. An infrared camera receives light reflected by the tissue from a second part of the imaging device. The camera captures light while the second part is off, and while the second part is on to generate corresponding signals, and differences the signals to generate an image. An array of LDs generates a grid of spots on the tissue, which is reflected to the camera. A coupled phone, tablet, or computer receives and processes the time-of-flight measurement, the image, and the reflected grid of spots.