Patent application number | Description | Published |
20110049368 | RADIATION DETECTOR WITH MICROSTRUCTURED SILICON - A radiation detector includes material for absorbing incident radiation, and for providing a response to heating caused by the absorption of photons from the incident radiation. The radiation detector may include multiple pixels, each with one or more layers of absorbing material. The absorbing material may include black (microstructured) silicon, which has the advantage of being a good absorber of radiation in the short wave infrared (SWIR) wavelengths (as well as ultraviolet (UV) wavelengths and visible light wavelengths). The radiation detector may include multiple pixels, each separately responding to radiation incident on that pixel, and each including black silicon (as well as possibly other absorptive materials). The pixels of the detector may each have cantilevered attachment to a frame of the detector, with differences in coefficient of thermal expansion of materials of the pixels causing deflection of parts of the pixels due to heating from absorption of radiation. | 03-03-2011 |
20120074294 | DISCRETE WAVEFRONT SAMPLING USING A VARIABLE TRANSMISSION FILTER - A discrete wavefront measurement device uses a variable transmission filter (VTF) to decouple the dynamic range of tilt angle measurements in the wavefront from the spatial sampling resolution and the measurement sensitivity as regards the physics of the readout. This approach allows the discrete wavefront measurement device to be configured to a specified dynamic range, transverse sampling resolution and measurement sensitivity at low cost. | 03-29-2012 |
20120105832 | ANGLE MEASUREMENT FOR A WIDE FIELD-OF-VIEW (WFOV) SEMI-ACTIVE LASER (SAL) SEEKER - A SAL seeker focuses laser energy reflected off a target into a spot on the surface of a multi-segment non-imaging detector. A matched filter is responsive to the normalized detector response to estimate an angle measurement to the target. The matched filter is particularly well-suited for use in wide FOV systems as it unambiguously selects the angle measurement over the extended FOV whereas the conventional centroid calculation introduces ambiguity. The centroid calculation and angle selection may be used to improve the search and selection of the matched filter. Alternately, the matched filter may be used to disambiguate the angle selection based on the centroid calculation. | 05-03-2012 |
20120143551 | Fixed-Source Array Test Station for Calibration of a Semi-Active Laser (SAL) Seeker - A fixed-source array test station provides a cost-effective high-throughput test bed for testing optical sensors that require stimulus at fixed angular positions. A SAL seeker requires stimulus at fixed angular position across its FOV to calibrate its spatial transfer function (STF). An array of fixed collimated sources at different angular positions is aligned so that their beams overlap the entrance pupil of the sensor under test. Each source may comprise an inexpensive light emitting diode (LED) or vertical cavity surface emitting laser (VCSEL) and collimator. To simplify alignment the sources may be positioned on and perpendicular to the surface of a sphere with the seeker's entrance pupil located at the center of the sphere. The sources are activated in accordance with an activation profile in order to calibrate or otherwise test the sensor. | 06-07-2012 |
20120249803 | MOTIONLESS FOCUS EVALUATION TEST STATION FOR ELECTRO-OPTIC (EO) SENSORS - A motionless focus evaluation test station is provided for measuring detector position error of EO sensors that do not possess dynamic focus capability. A positionally-fixed source emits EM radiation that diverges along an optical axis of the test station. Collimating optics collimate the EM radiation and direct it along the optical axis to the EO sensor. A positionally-fixed target is placed in the path of the diverging EM radiation nominally at the focal plane of the collimating optics. The target comprises a limiting aperture that exhibits an induced shift in optical focus at different positions along the aperture such that different positions on the target are imaged to different focal planes at the detector. The detector captures an image of the target that is blurred to either side of the spatial position that is optically conjugate to the actual detector position. A processor processes the image to measure the blur as function of spatial position to measure the actual detector position and output detector position error from a desired detector position. | 10-04-2012 |
20140231650 | DIGITALLY SCANNED MULTI-CELL ELECTRO-OPTIC SENSOR - A digitally scanned multi-cell EO sensor comprises a low-resolution multi-cell imaging detector. An array of optical focusing elements decomposes the sensor's FOV into at least four sub-fields. A sub-field directing array and focusing optic direct the optical radiation onto the imaging detector. In a first tilt mode, the optical radiation from the sub-fields is directed into at least four spatially separated sub-regions that each map to a different detector cell. A high-resolution spatial light modulator (SLM) digitally scans the FOV to select different portions of the FOV to map onto the different detector cells to time demultiplex spatially overlapping portions of the FOV onto each detector cell to stitch together a sub-image of a selected area of the FOV up to the native resolution of the SLM. | 08-21-2014 |
20140320843 | TIME-MULTIPLEXED BROADBAND AND MULTI-FILTERED ELECTRO-OPTIC SENSOR - An EO sensor is configured to time multiplex a primary optical channel that provides high detection sensitivity to maintain high SNR and a multi-filtered optical channel that provides detection in different measurement bands (e.g. spectral, polarization, amplitude or phase). The channels may, for example, be time multiplexed based on range to target or within each integration period of the EO sensor. The multi-filtered optical channel uses a field directing array to sample the FOV to form different optical sub-channels that are filtered by different optical filters. These sub-channels may be spatially multiplexed onto different sub-regions of the detector or may be time multiplexed onto the entire detector. The light modulator used to time multiplex the primary and multi-filtered optical channels may be used to time de-multiplex spatially overlapping regions of the FOV onto a pixel of the detector in order to detect high spatial resolution images with low resolution detectors. | 10-30-2014 |
20150211849 | SHARED-APERTURE ELECTRO-OPTIC IMAGING AND RANGING SENSOR - A shared-aperture EO imaging and ranging sensor is implemented by time multiplexing an optical imaging channel and an optical ranging channel. The optical ranging channel is allocated the “unused portion” of each frame; that portion of the frame that is reserved from electronics processing of the imaging channel. The electronics processing of ranging channel is performed during the integration period of the next frame. This allows ranging to be provided without sacrificing the performance of the imaging channel. Ranging may be provided using either “coded aperture” or “wavefront coding”. | 07-30-2015 |