Abstract: A cold stage actuation system employs an optical assembly having an adapter ring mounted to a flange connected to a cold finger which extends into a Dewar housing. The flange supports a detector array. A resilient cold shield extends from the adapter ring to a lens holder, the lens holder connected to the resilient cold shield distal from the adapter ring. The lens holder supports a lenslet array. An optical light shield extends from the lens holder oppositely from the resilient cold shield to proximate a window in the Dewar housing. A motor is supported within the Dewar housing. An insulating translation arm connects the motor to the optical light shield, whereby operation of the motor induces the insulating translation arm to extend or retract the optical assembly concentric with an optical axis.

Abstract: A cold stage actuation system employs an optical assembly having an adapter ring mounted to a flange connected to a cold finger which extends into a dewar. The flange supports a detector array. A resilient cold shield extends from the adapter ring to a lens holder, the lens holder connected to the resilient cold shield distal from the adapter ring. The lens holder supports a lenslet array. An optical light shield extends from the lens holder oppositely from the resilient cold shield to proximate a window in the dewar. A motor is supported within the dewar. An insulating translation arm connects the motor to the optical light shield, whereby operation of the motor induces the insulating translation arm to extend or retract the optical assembly concentric with an optical axis.

Abstract: A spectral radiation gas detector has at least one lenslet with a circular blazed grating for diffraction of radiation to a focal plane. A detector is located at the focal plane receiving radiation passing through the at least one lenslet for detection at a predetermined diffraction order. A plurality of order filters are associated with the at least one lenslet to pass radiation at wavelengths corresponding to the predetermined diffraction order, each filter blocking a selected set of higher orders. A controller is adapted to compare intensity at pixels in the detector associated with each of the plurality of order filters and further adapted to determine a change in intensity exceeding a threshold.

Abstract: A spectral radiation gas detector has at least one lenslet with a circular blazed grating for diffraction of radiation to a focal plane. A detector is located at the focal plane receiving radiation passing through the at least one lenslet for detection at a predetermined diffraction order. A plurality of order filters are associated with the at least one lenslet to pass radiation at wavelengths corresponding to the predetermined diffraction order, each filter blocking a selected set of higher orders. A controller is adapted to compare intensity at pixels in the detector associated with each of the plurality of order filters and further adapted to determine a change in intensity exceeding a threshold.

Abstract: A spectral radiation gas detector has at least one lenslet with a circular blazed grating for diffraction of radiation to a focal plane. A detector is located at the focal plane receiving radiation passing through the at least one lenslet for detection at a predetermined diffraction order. A plurality of order filters are associated with the at least one lenslet to pass radiation at wavelengths corresponding to the predetermined diffraction order, each filter blocking a selected set of higher orders. A controller is adapted to compare intensity at pixels in the detector associated with each of the plurality of order filters and further adapted to determine a change in intensity exceeding a threshold.

Abstract: A spectral radiation gas detector has at least one lenslet with a circular blazed grating for diffraction of radiation to a focal plane. A detector is located at the focal plane receiving radiation passing through the at least one lenslet for detection at a predetermined diffraction order. A plurality of order filters are associated with the at least one lenslet to pass radiation at wavelengths corresponding to the predetermined diffraction order, each filter blocking a selected set of higher orders. A controller is adapted to compare intensity at pixels in the detector associated with each of the plurality of order filters and further adapted to determine a change in intensity exceeding a threshold.

Abstract: A spectral radiation detector employs at least one lenslet with a circular blazed grating for diffraction of radiation at a wavelength at nth order to a focal plane A detector is mounted at the focal plane receiving radiation passing through the at least one lenslet for detection at a predetermined order. At least one order filter associated with the at least one lenslet passes radiation at wavelengths corresponding to the predetermined order. In additional embodiments a polarizing filter is associated with the lenslet for additional discrimination of the radiation.

Abstract: An apparatus and method for imaging incoming radiation. The apparatus includes a radiation shield unit having a cavity. A detector array is positioned at least partially within the cavity and has a planar surface with at least one infrared detector affixed on the detector array. A diffractive optical array is positioned within the cavity and is in thermal communication with the radiation shield unit. The diffractive optical array is configured to diffract and direct the spectral components of the incoming radiation onto the detector array. The apparatus is in an external environment having a predetermined ambient temperature. The radiation shield unit, diffractive optical array and detector array may be temperature-controlled to a temperature that is within a few degrees of the ambient temperature. The radiation shield unit, diffractive optical array and detector array may be temperature-controlled to cryogenic temperatures.

Abstract: An apparatus and method for imaging incoming radiation. The apparatus includes a radiation shield unit having a cavity. A detector array is positioned at least partially within the cavity and has a planar surface with at least one infrared detector affixed on the detector array. A diffractive optical array is positioned within the cavity and is in thermal communication with the radiation shield unit. The diffractive optical array is configured to diffract and direct the spectral components of the incoming radiation onto the detector array. The apparatus is in an external environment having a predetermined ambient temperature. The radiation shield unit, diffractive optical array and detector array may be temperature-controlled to a temperature that is within a few degrees of the ambient temperature. The radiation shield unit, diffractive optical array and detector array may be temperature-controlled to cryogenic temperatures.

Abstract: A remote sensing device and method operable for detecting and analyzing gases, vapors and flame plumes using imaging. The gas imaging instrument includes a gas-leak imaging device, for example, an Image Multispectral Sensing (IMSS) device (10), enhanced by advanced image processing techniques and micro-miniature circuitry, and includes a GPS (21), a clock and computer means (24) that are collectively operable for logging positional, temporal and gas-leak data. These enhancements provide a portable instrument with the capability to not only remotely detect and image gases, including gas leaks, but additionally provide a record of the position and time the spectrometric gas-leak data were collected in a single device (camera) (25).

Abstract: An apparatus for detecting incoming radiation, including: a housing for receiving the incoming radiation, a lens attached to the housing to transmit incoming radiation into a radiation shield unit within the housing; a bandpass filter within the radiation shield unit to filter the incoming radiation falling outside a predetermined spectral band; an uncooled infrared detector within the radiation shield unit for detecting infrared radiation; wherein the bandpass filter is located along an optical path between the lens and the infrared detector; and wherein the lens optically focuses the incoming radiation onto the infrared detector. The radiation shield unit, the bandpass filter and the infrared detector are cooled to a temperature slightly less than room temperature, resulting in an improved signal to noise ratio of the image obtained.

Abstract: A remote sensing method for detecting and analyzing gases, vapors and flame plumes using an imaging spectrometer. The spectrometric instrument uses Image Multispectral Sensing (IMSS) technology, enhanced by advanced imaging processing techniques and micro-miniature circuitry. These enhancements provide a portable instrument with the capability to remotely detect and image gases, including gas leaks. The technology also provides an analysis of the gas including chemical species and concentrations. The instrument can also remotely detect, image and analyze flames and plumes in the same manner, providing an analysis of the chemical species and concentrations in the flame. Advanced image processing techniques are used to provide gas and plume images and analysis to the operator. These processing algorithms are implemented in micro-miniature circuits such as digital signal processors (DSP's) and field programmable gate arrays (FPGA's) to provide a field portable instrument.

Abstract: A remote sensing method for detecting and analyzing gases, vapors and flame plumes using an imaging spectrometer. The spectrometric instrument uses Image Multispectral Sensing (IMSS) technology, enhanced by advanced imaging processing techniques and micro-miniature circuitry. These enhancements provide a portable instrument with the capability to remotely detect and image gases, including gas leaks. The technology also provides an analysis of the gas including chemical species and concentrations. The instrument can also remotely detect, image and analyze flames and plumes in the same manner, providing an analysis of the chemical species and concentrations in the flame. Advanced image processing techniques are used to provide gas and plume images and analysis to the operator. These processing algorithms are implemented in micro-miniature circuits such as digital signal processors (DSP's) and field programmable gate arrays (FPGA's) to provide a field portable instrument.

Abstract: An apparatus for spectral detection of remote objects. The apparatus consists of an input optic which focuses the field of view onto an image receiving surface consisting of an addressable spatial mask. The mask sequentially projects portions of the scene onto a diffractive optical element which focuses onto a photodetector array. The first image receiving surface of mask is partitioned into independently addressable and controllable subsurfaces, or gates, adapted to receive an electronic control signal from a programmable control signal generator. Each gate in the receiving mask directs a portion of the image incident thereon to a diffractive lens in response to a control signal communicated thereto. This gated image is dispersed by the diffractive lens and focused upon the photosensitive surface of a photodetector array. The photodetector array is partitioned into pixels having a number in ratio to the gates in the addressable mask.

Abstract: A spectrophotometer useful for spectral analysis of light emanating from one or more targets within an image is described. The apparatus comprises a diffractive lens having an optical axis, a planar array of photodetector elements (pixels), a means for changing the distance between the photodetector array and the diffractive lens along the optical axis and a signal processor. If either the photodetector array or the lens is moved along the optical axis, different wavelengths of light from each target within the image come into and out of focus on particular photodetector elements in the plane of the photodetector array generating sequential images corresponding to different wavelengths. By tracking each pixel's output in the photodetector array as a function of lens position relative to the photodetector array, the spectral composition of each target within the image is generated.