Abstract: A temporal-spectral multiplexing sensor for simultaneous or near simultaneous spatial-temporal-spectral analysis of an incoming optical radiation field. A spectral encoder produces a time series of spectrally encoded optical images at a high sampling rate. A series of full panchromatic spectrally encoded optical images are collected at a rate similar to the sampling rate. A detector records at least one spatial region of the spectrally encoded optical image. A processor is configured to process two series of spectrally encoded optical images to produce an artifact-free spectral image. The processing includes using the panchromatic images to normalize the spectrally encoded images, and decoding the normalized encoded images to produce high fidelity spectral signatures, free of temporal artifacts due to fluctuations at frequencies slower than the sampling rate for polychromatic images.

Abstract: A temporal-spectral multiplexing sensor for simultaneous or near simultaneous spatial-temporal-spectral analysis of an incoming optical radiation field. A spectral encoder produces a time series of spectrally encoded optical images at a high sampling rate. A series of full panchromatic spectrally encoded optical images are collected at a rate similar to the sampling rate. A detector records at least one spatial region of the spectrally encoded optical image. A processor is configured to process two series of spectrally encoded optical images to produce an artifact-free spectral image. The processing includes using the panchromatic images to normalize the spectrally encoded images, and decoding the normalized encoded images to produce high fidelity spectral signatures, free of temporal artifacts due to fluctuations at frequencies slower than the sampling rate for polychromatic images.

Abstract: A single-shot spectral imager or imaging system which acquires multiplexed spatial and spectral data in a single snapshot with high optical collection efficiency and with the speed limited only by the readout time of the detector circuitry. The imager uses dispersive optics together with spatial light modulators to encode a mathematical transform onto the acquired spatial-spectral data. A multitude of encoded images is recorded simultaneously on a focal plane array and subsequently decoded to produce a spectral/spatial hypercube.

Abstract: An adaptive spectral sensor, and methods of using the sensor. The sensor uses a programmable band pass transmission filter to produce both contrast signals, which discriminate specific target materials from background materials by comparing spectral signatures in hardware, and scene radiance spectra. The adaptive spectral sensor may measure one or more scene spectra and may form a spectral image. The sensor may automatically adjust to changing spectral, spatial and temporal conditions in the environment being monitored, by changing sensor resolution in those dimensions and by changing the detection band pass. The programmable band pass can be changed on-the-fly in real time to implement a variety of detection techniques in hardware or measure the spatial or spectral signatures of specific materials and scenes.

Abstract: A single-shot spectral imager or imaging system which acquires multiplexed spatial and spectral data in a single snapshot with high optical collection efficiency and with the speed limited only by the readout time of the detector circuitry. The imager uses dispersive optics together with spatial light modulators to encode a mathematical transform onto the acquired spatial-spectral data. A multitude of encoded images is recorded simultaneously on a focal plane array and subsequently decoded to produce a spectral/spatial hypercube.

Abstract: A spectral encoder for producing spectrally selected images of a radiation field containing multiple spectral components. An imaging spectrograph defines a first optical path that produces from the input radiation field a spectrally dispersed image comprising multiple spectral components displaced along a dispersion direction. Spectral pass bands are encoded on the dispersed image by a programmable spatial light modulator using one or more spatial masks. The imaging spectrograph further defines a second optical path that reverses the spectral dispersion of the first path and produces a spectrally-encoded polychromatic output image containing only those spectral components encoded by the spatial mask. The first and second optical paths share a common dispersing element. A detector records at least one spatial region of the spectrally encoded output image.

Abstract: A spectral encoder for producing spectrally selected images of a radiation field containing multiple spectral components. An imaging spectrograph defines a first optical path that produces from the input radiation field a spectrally dispersed image comprising multiple spectral components displaced along a dispersion direction. Spectral pass bands are encoded on the dispersed image by a programmable spatial light modulator using one or more spatial masks. The imaging spectrograph further defines a second optical path that reverses the spectral dispersion of the first path and produces a spectrally-encoded polychromatic output image containing only those spectral components encoded by the spatial mask. The first and second optical paths share a common dispersing element. A detector records at least one spatial region of the spectrally encoded output image.

Abstract: An optical light source for use in wavelength division multiplexed and dense wavelength division multiplexed systems may include a reference gas contained by a hermetically sealed enclosure which also protects a plurality of light generating structures. A frequency grid generator, typically in the form of an optical etalon, can be frequency referenced to an absolute reference point provided by the reference gas. An electronic feedback control system acts upon injection current to keep the laser frequency coincident with that of the referencing structure. An active, feedback based, thermal management systems provides control of the laser frequency ranges and etalon operating point. Electronic control over a number of separate lasers (and the grid) may be effected using a multiplexed digital controller.

Abstract: A high performance reconfigurable DWDM transmitter incorporates discrete optical components placed in v grooves etched in a substrate. Direct wavelength monitoring can be achieved with wavelength modulation locking applied independently to a gas absorption line and to etalon fringes. A set of equally-spaced wavelengths may be provided by a set of lasers, or a single laser can be used for a number of fixed frequencies.

Abstract: The invention provides a high performance reconfigurable DWDM transmitter incorporating low cost discrete optical components which can be placed in v grooves etched in a silicon optical micro-board or the like, keeping costs of manufacturing low. The lasers can be packaged in modules based on the technology of meso scale optics. The physical size of a multi channel module can be no bigger than a conventional single laser module.

Abstract: This specification discloses a method and apparatus for the mobile and remote detection of a gas, such as methane, in the atmosphere. The apparatus includes a TDL based Light Detection and Ranging (LIDAR) driven at carrier frequency lying within the absorption line of the gas. The apparatus also drives the TDL with a modulation frequency to generate upper and lower sidebands in the output of the TDL and with a low ramp frequency to sweep the output of the TDL across twice the width of the pressure-broadened absorption line of the gas, preferably the first overtone absorption line in the case of methane detection. Suitable power for remote detection through use of the TDL is provided by a master oscillator/fiber amplifier transmitter has no moving or adjustable parts at all. An all-solid-state monolithic and integrated amplifier is achieved, which leads to a compact and virtually maintenance-free LIDAR system.

Abstract: This specification discloses a method and apparatus for the mobile and remote detection of a gas, such as methane, in the atmosphere. The apparatus includes a TDL based Light Detection and Ranging (LIDAR) driven at carrier frequency lying within the absorption line of the gas. The apparatus also drives the TDL with a modulation frequency to generate upper and lower sidebands in the output of the TDL and with a low ramp frequency to sweep the output of the TDL across twice the width of the pressure-broadened absorption line of the gas, preferably the first overtone absorption line in the case of methane detection. Suitable power for remote detection through use of the TDL is provided by a master oscillator/fiber amplifier transmitter has no moving or adjustable parts at all. An all-solid-state monolithic and integrated amplifier is achieved, which leads to a compact and virtually maintenance-free LIDAR system.

Abstract: An optical light source for use in wavelength division multiplexed and dense wavelength division multiplexed systems may include a reference gas contained by a hermetically sealed enclosure which also protects a plurality of light generating structures. A frequency grid generator, typically in the form of an optical etalon, can be frequency referenced to an absolute reference point provided by the reference gas. An electronic feedback control system acts upon injection current to keep the laser frequency coincident with that of the referencing structure. An active, feedback based, thermal management systems provides control of the laser frequency ranges and etalon operating point.. Electronic control over a number of separate lasers (and the grid) may be effected using a multiplexed digital controller.