Abstract: An erosion-resistant, chemically vapor-deposited zinc sulfide window and method of making the same are disclosed. The method includes the step of immersing a chemically vapor-deposited or a hot isostatic pressed, chemically vapor-deposited zinc sulfide body into a liquid comprising gallium, the liquid having a temperature of about 600.degree. C. to about 1000.degree. C., for at least about thirty minutes to form a gallium-doped body. The gallium-doped, chemically vapor-deposited zinc sulfide body according to the invention is one capable of transmitting light having a wavelength in the range of about 300 nanometers to about 15,000 nanometers. Furthermore, the gallium-doped, chemically vapor-deposited zinc sulfide window according to the invention is capable of transmitting light, having a wavelength in the range of about 380 nanometers to about 700 nanometers have been exposed to rain erosion for 20 minutes at 470 miles per hour with a 90.degree.

Abstract: A window structure includes a first window layer having a zinc sulfide substrate coated on each side with an antireflective coating, and a second window layer having a bulk silicon substrate coated on each side with an antireflective coating. The two window layers are bonded together in a facing-but-spaced-apart relation by an infrared-transparent adhesive layer, preferably a silicone rubber. A targeting/sensor system using the window structure includes a targeting laser and a sensor within a housing having the window structure in its wall.

Abstract: A low force actuator that is used in conjunction with semi-active and passive suspension systems to provide for improved suspension and ride control for vehicles, and which overcomes stiction and provides limited active capability. The low force actuator is sized to counter the small, high frequency forces (caused by road input disturbances and stiction effects) that act on, or are transmitted between sprung and unsprung masses of the vehicle. The present invention provides for two low force actuators. The first comprises a proof mass low force electromagnetic actuator that may be connected to either the sprung or unsprung mass. In either configuration the proof mass provides an extra degree of freedom for the suspension system that decouples ride and holding control actions of the vehicle. The second comprises a differential force actuator that uses an electromagnetic actuator to provide a force between the sprung and unsprung masses of the vehicle.

Abstract: A system and a method of designing and mechanical packaging of a fully integrated multifunctional multispectral miniaturized sight assembly to allow its use on hand-held man-portable units. All the subsystems of the compact sight assembly, namely, a direct view day subsystem, a CCD-based visible TV subsystem, a staring IR night subsystem, an eyesafe laser rangefinding subsystem and a display subsystem for viewing the output of the TV or IR subsystem, are aligned and use a single telescope and eyepiece in order to decrease the size of the assembly. In addition, each sight assembly subsystem operates in a first and a second field of view, preferably in a narrow field of view and a wide field of view, with wavelengths from 0.45 .mu.m to 12 .mu.m, thereby creating a very small but highly powerful sight assembly.

Abstract: A system that automatically aligns and stabilizes off-gimbal electro-optical passive and active sensors of an electro-optical system. The alignment and stabilization system dynamically boresights and aligns one or more sensor input beams and an output beam of a laser using automatic closed loop feedback, a reference detector and stabilization mirror disposed on a gimbal, off-gimbal optical-reference sources and two alignment mirrors. Aligning the one or more sensors and laser to the on-gimbal reference detector is equivalent to having the sensors and laser mounted on the stabilized gimbal with the stabilization mirror providing a common optical path for enhanced stabilization of both the sensor and laser lines of sight.

Abstract: A corrector mirror folds the optical path between the objective and relay portions of a three-mirror anastigmat. The corrector mirror is a non-powered mirror having a nominally flat but higher order aspheric surface. By placing the corrector mirror between the objective portion and an intermediate image formed by the objective portion, the field offset of the anastigmat can be significantly increased. A large field offset makes the off-axis anastigmat ideal for use with an on-axis dewar for infrared imaging applications.

Abstract: An optical gun sight system for an M1A2 Abrams Main Battle Tank supported in a lower housing which may be attached to the fixed internal upper housing in the turret of the tank. An adapter plate is provided which has two sets of openings, one to align with the openings in the upper housing and the other to align with openings in the lower housing. An alignment mechanism allows for fine adjustment of the lower housing relative to the upper housing. Operating buttons, knobs and filter wheel are conveniently located on or beneath the front face of the lower housing. A thermal imaging system includes an objective lens for receiving an image of a target object, an eyepiece lens for viewing the image of the object, and a compensator lens movably located between the objective and eyepiece lenses for providing a thermal image of the object.

Abstract: Methods and apparatus for improving the thermal performance of a slab laser pump cavity is provided. Absorbing regions placed on either side of an active lasing region through which the active region is pumped provides uniform heat dissipation across the width of the slab thereby providing one-dimensional heat flow perpendicular to the broad surfaces of the lasing medium and maintaining uniform lensing and birefringence. Foreshortened cold plates in thermal communication with the active lasing region also provide improved thermal performance by providing uniform one-dimensional heat flow perpendicular to the broad surfaces of the lasing slab. In addition, a compliant thermal interface of variable thickness is provided to also improve the distribution of heat flow. Further, cooling channels located within the cold plates are located to achieve uniform one-dimensional heat flow.

Abstract: A system for passively sensing low frequency (5 Hz to 50 kHz) EM emanations from vehicles and classifying them on that basis. A temporal frequency response is computed for the sensed EM emanations. Harmonic, non-harmonic and temporal features are extracted from the response and used to classify the vehicle. In the preferred embodiment, the temporal frequency response is displayed as a time, frequency and intensity plot, from which a technician visually extracts these features. The features can then be used either to determine a "signature" for classifying the vehicle or to determine specific characteristics which, in turn, can be used to classify the vehicle. Alternately, the feature extraction and classification can be performed by an automated classifier.

Abstract: A solid-state power processor circuit and method is used to supply power to generate a discharge in a corona discharge pollutant destruction apparatus. The circuit uses field effect transistors (FETs) and integrated circuit devices based upon metal oxide semiconductor field effect transistor (MOSFET) technology to amplify low-voltage pulse signals to high voltage levels. A resonator in the power processor circuit generates sinusoidal oscillation from the high voltage pulses, and provides the high-voltage, high-frequency electrical power necessary for corona discharge.

Abstract: A process is provided for cleaning, disinfecting, and sterilizing substrates comprising the steps of: (a) placing the contaminated substrate in a cleaning vessel; (b) contacting the contaminated substrate with dense phase carbon dioxide in liquid form; (c) subjecting the substrate and the dense phase carbon dioxide to ultraviolet radiation having a wavelength within the range of about 180 to 300 nm for a duration and intensity sufficient to produce a photochemical reaction capable of destroying the DNA of microorganisms on the substrate; (d) substantially simultaneously subjecting at least the dense phase carbon dioxide to agitation; and (e) removing the dense phase carbon dioxide from the cleaning vessel and thereby transporting the contaminants from the substrate such that the substrate is cleaned and, in the case of contaminated garments, disinfected or, in the case of medical and dental instrumentation, sterilized.

Abstract: An eyesafe laser (10) transmitter having a single resonator cavity (16) for both the pump laser and the optical parametric oscillator (22). A Nd:YAG rod (24) provides gain for light at a first wavelength. A combined Q-switch/Brewster plate (26) Q-switches the light to increase its intensity and polarizes the light so that its polarization plane is perpendicular to the Z-axis of a KTP crystal functioning as the optical parametric oscillator, thereby providing type II phase matching conditions. The optical parametric oscillator transforms the light at the first wavelength to light at a second wavelength which is output thorough a partially reflective outcoupler at a wavelength which will not harm the eyes.

Abstract: A video demultiplexing interface (70) is used in a missile tracking system (10) employing a missile (12) with a thermal beacon (24). A target designator (40) defines a boresight from a missile firing location, such as an aircraft, to a target. The closed-loop tracking system (10) employs a forward looking infrared (FLIR) sensor (52) to track the displacement of the thermal beacon (24) from the boresight and generates a correction signal related to such displacement. The video demultiplexing interface (70) transforms serial multiplexed video signals, which are output by the FLIR sensor (52) and contain a field with M rows and L columns of pixels, into a demultiplexed parallel video signal containing N selectable adjacent horizontal rows of pixels (where N is less than M). A video thermal tracker (58) selects the N adjacent horizontal rows of pixels and generates azimuth and elevation error signals which are transmitted to the missile (12).

Abstract: An apparatus for destroying a buried object includes a targeting system including a sensor operable to detect the presence and location of an object which is at least partially buried in the ground, a gun system including a gun operable to fire a projectile into the ground, and a control system that aims the gun responsive to the presence and location of the buried object as determined by the targeting system. The sensor also desirably detects the presence and location of the projectile fired by the gun system, and the gun pointer is responsive to the location of the projectile. The sensor thus detects the presence of the buried object, the control system aims the gun at the buried object, and the gun fires the projectile. The sensor detects the relative positions of the buried object and the projectile as it passes near the buried object, the control system corrects the aim of the gun in the event that the prior shot misses, and the gun fires another projectile with a corrected aim.

Abstract: A laser crystal (25) having a relatively short optical length functions as a seed laser (1) and simultaneously establishes the wide separation between longitudinal modes. Pulsed operation causes multiple longitudinal modes to co-exist before competition acts to extinguish modes. The seed laser (1) is isolated from the relatively higher peak power output beam (4). Further, the injection seeded slave resonator (6) optical cavity length is adjusted by mechanical, electromechanical and/or electro-optical component(s) to harmonize the slave resonator optical cavity to the seed laser (1) optical cavity. A number of widely separated longitudinal modes are simultaneously output as a pulsed, high optical quality beam having a broad frequency range, short temporal coherence, and stable simultaneous operation of the several modes.

Abstract: A laser pump cavity apparatus with integral concentrator provides improved thermal lensing control, cooling and fracture strength. The concentrator is formed around a doped solid-state laser medium by diffusion bonding, using a material different than the doped laser medium and with a substantially lower index of refraction, higher thermal conductivity and higher stress fracture strength than the doped laser crystal. The concentrator has a top cladding layer with a cylindrical focusing surface and a bottom cladding layer with a cylindrical focusing surface and may have edge cladding layers. Cold plates, each of which also has one cylindrical surface, are placed in thermal contact with the cylindrical surfaces of the top and bottom cladding layers. The cylindrical surfaces preferably have hyperbolic or quasi-hyperbolic shape. The laser pump cavity apparatus is preferably pumped with several laser diode arrays in directions transverse to a laser beam axis.

Abstract: A driven armature cylinder and piston link with reduced side loads and cross-bearing loads which uses a pin inserted through a dual coaxial tapered through bore in the drive piston to secure a drive piston to a displacer or compressor module cylinder, as applicable to Stirling cycle cryocoolers. Another embodiment is a method of coupling a piston to an armature cylinder with a linkage pin inserted through a dual coaxial tapered through bore to assure that the impact forces between the linkage pin and the drive piston occur at the centerline of the drive piston for centered loading and reduction of side and cross-bearing loads.

Abstract: A kinoform optical element (KOE) has different surface relief heights in different zones of the kinoform surface, in order to optimize the first order diffraction efficiency in each zone. By increasing the first order diffraction efficiency, noise as well as ghost image problems may be reduced and contrast and resolution may be enhanced. In an exemplary embodiment, each zone, or even different areas of the same zone, has a non-constant step height that is preferably defined by a predetermined relationship between an optimal step height and an associated predominant angle of incidence associated with that particular zone or area. In the case of an optical system having a relatively large aperture and a relatively narrow field of view, each point of the KOE sees the entire image; the associated predominant angle of incidence at that point may be defined by a so-called "marginal" ray from the center of the entire image space (i.e., on the optical axis and at the effective "middle" of the usable depth of field).

Abstract: An improved ion mobility spectrometer for detecting chemical warfare agents and hazardous vapors. The ion mobility spectrometer has an improved sensor cell that includes a heated air flow assembly, an ionization assembly and a field electrode and detector assembly printed circuit assembly. The heated air flow assembly includes a cover with an air inlet, an ambient temperature sensor, a thin-film heater element, a heater frame, a heated air sensor, and a heater channel formed therein. The ionization assembly comprises a nuclear ionization source attached to a holder, a lid, and an ionization channel formed therein that is coupled to the heater channel. The field electrode and detector assembly printed circuit assembly comprises a field electrode printed circuit board, a detector electrode printed circuit board, and detector electronics. The field electrode printed circuit board has a plurality of field electrodes disposed on a bottom surface thereof.

Abstract: A solid, one-component, flexible epoxy-based composition and method for making the same are provided. The present compositions comprise: (a) an epoxy-terminated prepolymer formed by reacting at least four moles of a polyepoxide resin with approximately one mole of a diamine compound, wherein at least one of the polyepoxide resin and diamine compound is solid at room temperature, and wherein the prepolymer is rheologically stable for weeks as a single component mixture at room temperature and, and (b) a substantially stoichiometric amount of an epoxy resin curing agent selected from the group consisting of a heat-curable, latent epoxy resin curing agent and a room temperature-curable ketimine curing agent. Optional components include thixotropic agents, diluents, fillers, anti-oxidants, and processing aids. The present uncured epoxy-based compositions upon cure, exhibit a durometer Shore D of less than about 45 (or a durometer Shore A of less than about 100).