Abstract: An infrared image is directed onto a transducer having a planar array of absorbing discs, on one side. The discs are supported by a thin membrane which sags or bulges as the discs heat up. The discs thus change their spacings with respect to a partially reflective mirror. The nominal spacing between the discs and mirror is about ¼ wave-length of the infrared radiation, such that absorption is enhanced. The mirror is supported on a transparent substrate through which visible or near-infrared radiation is shown; the mirror/discs thus establish a Fabry-Perot cavity for this radiation, whereby a visible or near-infrared image may be observed or detected as the various discs establish various spacings in accordance with incremental variations in the infrared image. An alternate embodiment uses an electrostatic field to pre-bias the discs toward the mirror and thus to tune or adjuct the sensitivity of the transducer.

Abstract: A far-infrared image is directed onto a transducer having a planar array of absorbing discs on one side. The discs are supported by a thin membrane ich expands and bulges as the discs heat up. The discs thus change their spacing with respect to a partially reflective mirror. The nominal spacing between the discs and mirror is about 1/4 wavelength of the infrared radiation, such that absorption is enhanced. The mirror is supported on a transparent substrate through which visible or near-infrared light is shown, and carries a perforated mask atop an insulating layer and in registration with the discs. The mirror/discs thus establish a Fabry-Perot cavity for the visible or near-infrared light, whereby a visible or near-infrared image may be observed or detected as the various discs establish various spacings in accordance with incremental variations in the infrared image. An electrostatic field is established between the mirror and the shield by a voltage source.

Abstract: A filter is constructed consisting of an optical cavity having at least one element which is a square mesh of highly-conductive metal on a transparent substrate. The mesh openings are defined by relatively narrow conductors of the metal. The mesh feature size, as determined by the sum of the conductor width and square size length, is below the diffraction limit for incoming radiation of interest.

Abstract: A laser oscillator system which transmits laser input beam pulses through a olarizer onto the surface of a rotating mirror which routes the laser beam pulses sequentially into a plurality of stationary phase conjugate amplifiers. The pulse repetition frequency of the oscillator input beam pulses is much higher than any one of the amplifiers can handle without overheating. The amplifiers are positioned in a circle around the laser oscillator axis. The polarizer and rotating mirror are positioned on the oscillator axis. The mirror is synchronized with the input beam pulses so that each subsequent input beam pulse enters the next amplifier in sequence. Each phase conjugate amplifier has associated therewith a quarter-wave plate and a phase conjugate mirror at its output. The phase conjugate mirror is preferably comprised of a focusing lens and a stimulated Brillouin scattering cell.

Abstract: A flip-up mounting bracket for use of a stripped down ground system type ht vision goggle on an aviators helmet. The frame and excess padding surrounding the ground system goggle is removed and the mounting bracket is substituted for the frame as a threadable mount for the ground system goggle. The bracket is rotatably connectable to standard aviators night vision imaging system (ANVIS) hardware on the helmet. The mounting bracket and goggles are rotatable about the hardware for stowing the ground system goggles up in the vertical flip-up position or down in the direct view of the pilot for use in night observation.

Abstract: A double conjugate laser beam amplifier which twice conjugates the laser ut beam and provides an output beam in exactly the same direction and of the same polarization as the input beam while retaining the alignment stability of singly conjugated amplifiers even when the thin film polarizer between two conjugate amplifiers is not stable. A half-wave voltage at a Pockels cell positioned on the beam axis immediately prior to the polarizer controls whether the oscillator beam is transmitted through the polarizer or is reflected off the polarizer toward a first conjugate amplifier for amplification and retroflection back through the first conjugate amplifier and the polarizer into a second conjugate amplifier for further amplification and retroreflection back and is reflected off the polarizer a second time. The double conjugate amplifiers may be cascaded to both increase output and laser beam pulse repetition rate.

Abstract: An electrooptic support measure comprised of black hole radiometer within a orward looking infrared (FLIR) scanning imaging video processing system to provide friendly military personnel with the capability of surveying terrain to determine if enemy thermal imaging devices (TIDs), which have cryogenic temperature detectors therein, are being used in surveillance against the friendly military personnel. The lens and scanners of the FLIR scanning imaging video processing system have wide field of view (FOV) for search operation, and each of the plurality of the IR detectors that form an IR detector array operate as a plurality of radiometers having narrow (FOVs) when the black hole radiometer capability circuit of this disclosure is being used.

Abstract: A fast acting electromagnetically operated shutter for protecting an imag system from damaging light, such as intense laser light, comprised of a plurality of vane type shutters driven by magnetically moveable linear racks transferring linear to rotary motion to the midportion of each vane to aid in overcoming inertia. The linear racks are comprised of an upper rack at one end of the shutters and a lower rack at the opposite end of the shutters wherein both upper and lower racks simultaneously move reciprocally together. The racks have gear teeth thereon that are meshed with alternate vanes from first the upper and then the lower racks to transfer opposing directional rotation to adjacent vanes. An electronic shutter control means responds to input damaging light intensity signals impinging light detecting sensor means.

Abstract: A multichannel coincidence nuclear detector system for spectral charactertion of nuclear radiation sources at a remote location. The system is designed to detect and classify the radiation source in unfriendly territory and to provide a radio link back to a friendly receiver user station. The sensing elements are comprised of a plurality of plastic scintillator fiber sensors which may be several meters long and with each fiber having a different spectral sensitivity to gamma and neutron sources. Each of the scintillator fibers is connected to a transmitting optical fiber which may be 1 kilometer or more in length. The plurality of optical fibers transmit the optical signal generated by the radiation from a nuclear source impinging on the scintillator fibers to an electronic system. The electronic system is a sealed self contained battery operated device which is comprised of a photomuliplier detector and microprocessor based signal processing and data storage.

Abstract: A method of thermally isolating detector elements in an uncooled focal pl array. A backfill material of arsenic trisulfide is deposited inside reticulated grooves in a detector material to provide strength prior to the step of bump bonding the detector elements of the detector material to a readout device array. After the bump bonding step, an oxygen rich gas, such as a dry oxygen and nitrogen mixture, is flowed between the detector and readout arrays to remove the arsenic trisulfide material therefrom leaving an air gap between the detector elements.

Abstract: A pair of rail adapters which replace visor rails used on the U.S. Army Ahe helmets, i.e. the AH-64 helmet. The rail adapters have a concave inner portion that is form fitted and attachable to the Apache helmet, with one rail adapter on each of the right and left upper front sides of the Apache helmet. The rail adapters have a convex outer portion that interface and is attachable with a visor guard Aviator's Night Vision Imaging System (ANVIS) goggle assembly and visor which are normally used with the U.S. Army ANVIS helmet, i.e. the SPH-4 helmet. Each of the rail adapters is made in one piece which has a thick upper portion with a half dovetailed open track in which the outer portion of the visor guard is attachable thereto. The rail adapters have a thin lower portion which provides clearance with the visor and the ANVIS goggle assembly when the visor and the assembly are in the line of sight position.

Abstract: A helmet mounting structure for mounting aviator goggles to an Army Apache elmet. The structure is a single piece that is formed and shaped to conform to the curvature of the front portion of the Apache helmet and is held firmly thereto by specially designed screws that are loosely held by the single piece structure and are threaded into at least two mounting points on each of the left and right sides of the helmet. A breakaway mount support pad, formed in the center front of the mounting structure and extends downward therefrom, has a breakaway mount thereto. The goggles may then be connected to the breakaway mount attached for swiveling up to the stow position or down in the line of sight of the aviator.

Abstract: An Aided Target Recognition System (ATR) is provided wherein the recognit abilities of two ATR sensor subsystems with mutually exclusive false alarm characteristics are fused by a decision circuit to provide an improved false alarm rate versus the probability of target detection. The sensors, which respond to different types of radiation, have different false alarm patterns for the same set of targets and a decision circuit which contains logical function elements to exploit the difference in these patterns.

Abstract: A nonlinear optical fluid with radiation-absorbing small particles uniformly suspended in the fluid. For radiation below a threshold value, radiation passes through with slight attenuation. Above the threshold, only a limited level of radiation is passed, the limit being below the damage level of a sensitive optical detector.

Abstract: The invention provides a of simulating the performance of systems such as r-infrared imagers which must be described with shift variant spread functions and non white noise. Simple approximations are substituted for the spread functions and these are convolved with the pixel samples before and after the noise is added to produce a degraded but very realistic simulation of the video signal or other characteristic output of the system.

Abstract: A rapidly tunable low pressure laser comprised of a one electrode pair low ressure CO.sub.2 gas laser gain cell and intra-cavity quarterwave plate and Q-switch. The cell has a fixed laser output coupled at one end of the laser cavity and at the other end of the cavity a wavelength switching device which changes laser lines in less than 1.times.10.sup.-3 .mu.sec, i.e. changes the wavelengths in less than 1 millisecond within the low pressure laser, to produce at least two quick pulses of different wavelengths at a separation of 1 millisecond. The wavelength switching device is comprised of a fast rotating mirror on the laser optical axis and a fixed grating, or a rotating grating on the optical axis.

Abstract: A portable infrared landing site illumination system is provided for fixed ing and rotary wing aircraft having night vision capabilities as provided by the Army's second generation goggles (PVS-5) or the third generation goggles (ANVIS). The system employs special markers assembled from readily available disposable components and a simple above ground mounting stake. Also provided is a special laser illuminator which operates in several modes to assist all phases of the landing operation.

Abstract: New fiber optic elements and a new microchannel plate for proximity focus image intensifier tubes and a method for making them are provided. Higher resolution is provided at the center of the field of view by the use of graded fiber and channel sizes and by the use of convex and concave surfaces in proximity focus.

Abstract: A real time coding system for the transmission and reception of pictorial o-dimensional information at television (TV) rates. In one coding system, the input signal and a coding signal are modulo added in an operational amplifier and are transmitted therefrom as a coded signal, which may be a coded video signal. In the receiver, an operational amplifier receives the coded video signal along with an exact replica of the coding signal. The coding signal is subtracted from the coded video signal wherein the resulting original input signal is produced and fed to a TV type display, such as a CRT or electroluminescent flat panel. In a second coding system, a coding pattern is comprised of a transparent matrix structure which is substituted for a time varying signal. A flying spot scanner receives a voltage input signal from an operational amplifier and is controlled by a selected code for selectively scanning the transparent coding pattern matrix.

Abstract: The present invention provides layered devices to control the spatial and spectral distribution of energy in optical beams, particularly high-intensity laser beams. These devices include improved versions of prior art thin-film (vacuum-deposited) interference filters, rugate structure anti-reflection coatings, Q-switches, pulse shapers, modulators, optical bistable devices and the like. Control is provided using materials with large second and third order susceptibilities to electric field polarization and, if necessary, means to apply appropriate electric fields.