Abstract: A multi field of view (FOV) imaging system is disclosed. In one embodiment, a dual FOV imaging system includes a composite lens array including a first lens set positioned to focus a first type of FOV and a second lens set positioned to focus a second type of FOV and a composite focal plane array (FPA) including multiple focal plane arrays (FPAs). Further, the composite FPA is disposed at the first type of FOV and the second type of FOV for producing a seamless mosaic dual FOV image of a target region.

Abstract: A system and method for enhanced conditioning light so a camera can capture images from it in a variety of brightness ranges is presented. A camera has an optical lens and a photochromic filter. The photochromic filter may be placed in front of the lens. The photochromic filter extends an exposure range of the camera without the need for a mechanical iris.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: A compact momentum-balanced internal optical scanning mechanism is provided for a wide angle camera used in photo reconnaissance and the like, in which a large high resolution but not fully populated array is used to provide full scene coverage with high pixel densities, in which sharpness is maintained and in which the image can be scanned without vibration due to momentum compensation so that the image may be shifted on the focal plane array in such a manner that images focused on a dark portion of the array will move to an active portion of the array, with the sequential read out of the information concatenated into high resolution full scene image data.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: A multi field of view (FOV) imaging system is disclosed. In one embodiment, a dual FOV imaging system includes a composite lens array including a first lens set positioned to focus a first type of FOV and a second lens set positioned to focus a second type of FOV and a composite focal plane array (FPA) including multiple focal plane arrays (FPAs). Further, the composite FPA is disposed at the first type of FOV and the second type of FOV for producing a seamless mosaic dual FOV image of a target region.

Abstract: A compact momentum-balanced internal optical scanning mechanism is provided for a wide angle camera used in photo reconnaissance and the like, in which a large high resolution but not fully populated array is used to provide full scene coverage with high pixel densities, in which sharpness is maintained and in which the image can be scanned without vibration due to momentum compensation so that the image may be shifted on the focal plane array in such a manner that images focused on a dark portion of the array will move to an active portion of the array, with the sequential read out of the information concatenated into high resolution full scene image data.

Abstract: In the subject three-axis pointing system, the elevation and tip mirror axes are permanently mounted with their rotation axes orthogonal to each other to eliminate gimbal lock over the hemisphere, to avoid high accelerations as the zenith or nadir pointing directions are approached, and to provide optimal two-axis beam pointing control.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: In the subject three-axis pointing system, the elevation and tip mirror axes are permanently mounted with their rotation axes orthogonal to each other to eliminate gimbal lock over the hemisphere, to avoid high accelerations as the zenith or nadir pointing directions are approached, and to provide optimal two-axis beam pointing control.

Abstract: Methods and apparatus for rapid, accurate OSNR measurements by directly measuring the spectrally-resolved State of Polarization (SOP) variation across each DWDM channel and using a polarization controller to deterministically extinguish the signal across narrow frequency subbands within each DWDM channel. In-band ASE noise is subsequently measured as a function of frequency across the channel bandwidth.

Abstract: The present invention provides a method and apparatus for compensating for polarization mode dispersion in an optical transmission system without perturbing the laser source. The present invention compensates for PMD by transferring a sufficient fraction of the light signal in an optical transmission system substantially into a single PSP of the system. As a result, each light pulse in a data stream is not substantially mixed with temporally adjacent light pulses or bit periods.

Abstract: An athermalized delay line having two optical paths whose difference in optical path length is thermally insensitive. Each optical path typically includes a reflecting quarterwave plate, each path being fed by the output from a polarizing beamsplitter. The delay line is suitable for incorporation into a PMD compensator having at least one compensation stage formed from a polarization controller and an athermalized delay line.

Abstract: Methods and apparatus for rapid, accurate OSNR measurements by directly measuring the spectrally-resolved State of Polarization (SOP) variation across each DWDM channel and using a polarization controller to deterministically extinguish the signal across narrow frequency subbands within each DWDM channel. In-band ASE noise is subsequently measured as a function of frequency across the channel bandwidth.

Abstract: Methods and apparatus for correcting polarization mode dispersion (PMD) and other transmission distortions in a light signal. By performing measurements of polarization state versus frequency on an intrachannel basis, the first-order and higher-order variations in the polarization state in the channel due to distortions such as PMD may be identified and characterized. Having identified and characterized the variations, the effects of the distortion may be compensated for and substantially eliminated. The methods and apparatus are not limited to single channel configurations but, instead, embrace configuration such as DWDM that carry a plurality of communication channels over a single fiber link.

Abstract: Apparatus and methods for polarimetric measurements across a spectral range, such as determining the polarimetric state across a wavelength band in a wavelength-division multiplexed fiber optic channel. A variable phase delay is introduced between orthogonal polarization components in an incident light. The resulting intensity changes are used to compute parameters indicative of the polarimetric state of the light. These measurements may be used, for example, for polarimetric imaging, polarimetric component characterization, and measuring polarization states in a fiber link.

Abstract: The present invention provides a method and apparatus for compensating for polarization mode dispersion in an optical transmission system without perturbing the laser source. The present invention compensates for PMD by transferring a sufficient fraction of the light signal in an optical transmission system substantially into a single PSP of the system. As a result, each light pulse in a data stream is not substantially mixed with temporally adjacent light pulses or bit periods.

Abstract: A light transparent window is fabricated to absorb a band of radio frequency (RF) energy with minimal RF transmission and reflection. The window is formed from a series of parallel electrically conductive sheets separated by absorbing cavities. The conductive sheets are formed by depositing a layer of doped semiconductor material onto a thin layer of sapphire. The absorbing cavities are formed by an air-filled space between the conductive sheets. Radio frequency reflection can be further attenuated by an antireflection coating, which is preferably realized by a non-conducting sapphire sheet separated from the series of conductive sheets by an air-filled space. Depending on the number of cavities, reflection and transmission attenuation of over 25 dB can be obtained for radio frequency energy in the 2 to 18 GHz band.