Abstract: A panoramic imaging system is formed from select configurations of micro-optic multiplets (MOM) comprised of two microlens modules (MLM). The MLMs themselves are formed from arrays of microlenses. The present panoramic imaging system is characterized by the two MLMs configured on concentric approximately spherical surfaces. The optic axis of each of the microlenses is tilted slightly with respect to its neighbor to allow for proper alignment of images to form a single primary image on a substantially spherical global image surface.

Abstract: The present invention is directed to an apparatus and method for coupling a coherent fiber-optic bundle to an electro-optical sensor. This invention provides accuracy and durability of coupling in operating conditions characterized by vibrations, shocks and fluctuating temperatures and pressures. It also reduces the reject rate previously experienced in such assembly work. The apparatus and method of the present invention employ a rigid guide plate for initiating and in most cases preserving transverse and angular alignment of the component bundle and sensor, and a transparent flexible cement to establish the correct proximity between the electro-optical sensor and the fiber-optic bundle and to achieve permanent mating of those two components. In certain applications the rigid guide plate can be dispensed with after assembly and curing of the cement.

Abstract: An optically driven signal generator utilizes optical switches having a common output port and input ports alternately coupled to first and second potentials of opposite polarities. Optical pulses, with interpulse periods commensurate with a desired output frequency, sequentially operate the switches so that electrical signals of opposite polarities are alternately coupled to a common output port in a manner to establish a continuous electrical signal at a frequency that is commensurate with the interpulse periods.

Abstract: A scanning spectrometer scans the spread spectrum of sunlight and low level luminescence or fluorescence past a slit to provide the spectrum scanned in the time domain. An image intensifier responsive to the light energy passing through the slit is gated on when Fraunhofer lines are coincident with the slit. A photodetector responsive to the image intensifier detects the intensified total energy within each Fraunhofer line.

Abstract: Blooming inhibition in an intensified television camera having an image intensifier is effected by applying periodic electrical pulses to the photocathode of the image intensifier of an amplitude that absorbs into the photocathode of the image intensifier excessive electrons in the photocathode and in a space charge adjacent the photocathode resulting from a bright light point in the scene. The pulses are of such short duration that sensitivity of the camera is not significantly reduced. The periodicity of the pulses is such that a plurality of the pulses are applied during each raster line scan. Alternatively, one pulse may be applied during each raster line retrace.

Abstract: A gradient index rod lens is utilized to focus the intensified output image from an image intensifier onto the sensor surface of a focal plane array assembly through the window or filter of the focal plane array assembly.

Abstract: The range to an object is obtained by conveying light rays from the object through an afocal telescope to spatially displaced objective lenses that view the scene from two displaced points of view. The scene images from the objective lenses are focussed on two television sensors, respectively. The video frame from the TV sensors are digitized and stored in respective frame grabbers. A timing and logic circuit controls the television sensors and frame grabbers to alternately provide frames from the two television sensors to a monitor. The timing and logic circuit time shifts the output of one of the frame grabbers with respect to the output of the other frame grabber. A correlator responsive to the frame grabber outputs provides the correlation therebetween. The time shift required to bring the video images of the object into coincidence, at the correlation peak, provides a measure of the range to the object.

Abstract: The gating circuit includes a low voltage section and a high voltage section with a fast and a slow switch in the high voltage section for providing the gating pulses to the photocathode (PC) of the image intensifier. A high voltage isolated DC/DC power supply referenced to the MCPin terminal of the integral wrap around power supply of the image intensifier provides, to the fast and slow switches, positive and negative potentials referenced to MCPin. The negative potential is sufficient to turn the PC on and the positive potential is sufficient to turn the PC off and to clear burned in PC images. The high voltage isolated power supply provides high voltage isolation between the low voltage section and the reference input and outputs thereof in the high voltage section. A driver included in the high voltage section for driving the fast switch receives operating potentials from a low voltage isolated DC/DC power supply referenced to the high voltage supply.

Abstract: An apparatus for automatically controlling the photocathode of an image intensifier employed as a high speed shutter in a television camera utilizes the video signals established by the camera to provide first and second pulses representative of the light level at the camera. The lengths of these pulses are compared to time intervals representative of light levels whereat switching is provided that selects between the first pulse control of the photocathode and control of the photocathode by a train of pulses gated within the time interval of the second pulse.

Abstract: The system includes a television camera or an optical viewer device with a gated image intensifier input. A short intense laser pulse is transmitted to illuminate the scene. The image intensifier is gated on after a time delay equal to the round trip transit time of the pulse from a range slice of interest. The image intensifier is gated on for a time interval equal to the width of the laser pulse. In the television camera embodiment, one laser pulse per frame is transmitted and successive range slices are observed during successive frames by successively increasing the time delay. The range slice images are stored in a buffer and read out to a television display. In the optical viewer device embodiment, a segmented horizontally sliced electro-optical shutter is disposed adjacent the phosphor output of the image intensifier to transmit successive range slice information to an eyepiece of the device for viewing by an observer.

Abstract: A Kerr cell in an electro-optical shutter is coupled in a leg between "H connected" switches so as to reverse the polarity of the actuating potential applied across the cell.

Abstract: The microchannel plate current of a microchannel plate image intensifier is sensed to generate a pulse train applied to the image intensifier photocathode for gating the image intensifier on and off with an on period proportional to the light impinging thereon. The off periods of the pulse train are sufficiently positive to repair photocathode spot damage.

Abstract: A generator of short electromagnetic pulses utilizes a photoconductive switch having metallic strips on a substrate with a gap separation therebetween. A timing circuit provides an electrical signal to the input of the photoconductive switch and a trigger to an optical source causing a short burst of optical energy to illuminate the gap between the metallic strips, thereby causing the photoconductive substrate to provide a low impedance path between the metallic strips and coupling the electrical signal to an output terminal of the photoconductive switch for the duration of the optical pulse. A filter coupled to the output terminal of the switch, via an impedance matching section, selects a signal frequency band for further transmission.

Abstract: A variable coupler fiberoptic sensor in which a fused, tapered, biconical directional fiberoptic coupler is encapsulated in a stress birefringent medium whose index of refraction changes with applied stress.The ratio of power in the output fibers of the directional coupler varies with the change of index of refraction of the encapsulating medium as stress is applied to the medium.

Abstract: A device for automatically controlling the intensity of light impinging on the face plate of a television camera includes a shutter which is operated through a pulse width modulator so as to be opened for a length of time which varies inversely with the intensity of light entering the imaging light path between the scene and the camera.