Abstract: An electro-optical modulator/antenna operates in the tunable diffraction ting mode to vary the magnitude of the zero diffraction order and consequently transmits optical information. A relatively thin slab of lithium niobate or equivalent electro-optic material has its lateral surfaces optically polished and its C-axis, or optical axis, running parallel to the polished lateral surfaces. At least one set of interdigital metallic electrodes are deposited on the face or just within the lateral surfaces to form, among other things, a diffraction grating that is orthogonally disposed with respect to the C-axis. When a potential source is coupled to the interdigital electrodes, the electric fields between adjacent electrodes change the crystal's index of refraction in accordance with the linear transverse Pockel's effect.

Abstract: An all-weather, maximum resolution system visually presents a multi-color mposite image of plural selected spectral ranges of energy received from a common field of view. First, second, and third images of a selected common field of view are developed and respective, first, second and third sensors (each responsive to a different spectral range of energy) develop first, second, and third sets of electrical signals commensurate with the energy emanating from the selected common field of view. In a typical preferred embodiment the selected spectral ranges may comprise the visual range of light energy, the middle infrared range comprising light energy in the 3 to 5 micron region, and the far infrared range comprising light energy in the 8 to 10 micron region.

Abstract: A wide angle narrowband optical filter is provided by an assembly in which a body member supports multiple absorption materials in a common optical path. Each of the multiple absorption materials contributes toward narrowing the spectral bandwidth region permitting transmittance of light energy. A bandpass glass color filter restricts light transmission to a relatively broad spectral range of approximately 250 nanometers and a selected coumarin dye material in solution used with a second solution of a selected rare earth material narrows the spectral range of transmittance. In a preferred embodiment an interference filter further narrows the transmitting bandwidth to approximately 12.5 nanometers at FWHM (measured at Full Width Half Maximum) in the spectral region which is desirably coincident with the wavelengths of light energy best transmitted in ocean waters.

Abstract: The detection and localization of an antiship torpedo is accomplished by ustic and optical means. A ship's sonar determines the approximate location of the incoming torpedo and a laser scans this location with energy in the blue-green spectrum. Surface reflections are gated out of a linear detector array and reflected portions of the scanning beam which penetrate the water's surface are divided among the elements of the linear detector array into field of view element signals. These field of view element signals are subsequently compared in time and amplitude to determined disparities between them which point to the torpedo's position, depth and bearing. Optionally, spectral and polarizing filters are provided to enhance the signal to noise ratios and to facilitate signal processing.