Abstract: An improved apparatus and technique for providing frequency selective seng and tracking. An optical radar transmitter is constructed using a dye laser controlled by a Faraday cell having two end polarizers. The Faraday cell extends to intercept the return beam from the transmitting laser. Using a magnetic field to control the Faraday cell, the frequency of transmission can be selectively varied while the receiver-detector is automatically ganged to the transmitted frequency. The particular frequency selectivity provides significant isolation of the sensing beam from unwanted and interfering radiation allowing highly selective optical beam tracking.

Abstract: The adduct of phosphorous pentachloride (PCl.sub.5) and hexamethylphosphoramide ((Me.sub.2 N).sub.3 PO) and alkoxy derivatives thereof useful for enhancing the fire retardancy of polyesters and a method of enhancing the fire retardancy of general purpose polyester resins through the combination therewith of the aforedescribed alkoxy derivative.

Abstract: A laser system for producing short optical pulses with higher energy and controllable shape from a high power solid state laser system. The system includes two gratings at the output with an adjustable interferometer between the laser source and an amplifier element. Thus, the output pulse may be tailored to a particular shape.

Abstract: A method for determining the capability and optimum operating parameters of alkali halide crystals with anisotropic centers as holographic recording media by assessing the dispersion and absorption of polarized light by the anisotropic centers through a measurement of the difference in refractive index and absorption for light of different polarizations, the former through utilization of an ellipsometric technique wherein light passes successively through a polarizer, test crystal, analyzer, and detector.

Abstract: A fail-safe cable cutter device which prevents the release or loss of an ect lifted by a cable through a pulley in the event the object accidentally strikes the pulley and is lifted beyond its safe load condition; i.e., the object is "two-blocked.

Abstract: An optical power amplifier system for extracting high power radiation from a basic active laser media. The system includes a plurality of basically confocal mirrors so positioned that radiation output from a laser is amplified, that no power is absorbed in the supporting structure and it has no feedback from the secondary mirror. In the system, the laser beam passes through the active laser media region at least four times which increases the output power.

Abstract: The disclosed invention provides an accurate, simple and flexible method processing the receiver output of a high range resolution monopulse tracking radar to generate range and angle tracking error voltages based on the location of only the leading edge of the target echo replacing the conventional analog range error detectors and angle error processors in closed tracking loop systems. The invention also processes the radar return signal to avoid interference from repeater jammers or multipath returns at low angle tracking.

Abstract: An impurity concentration profile is established in a solid by attaching solid to a heat sink and irradiating it with one or more fast laser pulses. The impurity may initially be located in a surface layer or it may be dispersed throughout the solid.

Abstract: Rotation of a search radar antenna primary focusing structure about both elevation and optical axes provides stabilization of the radiated beam in both level and cross-level respectively.

Abstract: Measurement of the range of a detected target is accomplished through utiation of a large bistatic-angle radar system having two transmitters used in conjunction with a receiver indicating the duration of received target forward-scattered signals from each transmitter.

Abstract: An improved technique for eliminating interference in a signal processing stem exposed to multiple interference sources. A main receiving channel output and a plurality of auxiliary channel outputs are connected to form a canceller system where outputs from the canceller of each auxiliary channel are connected in parallel and subtracted from the main channel signal. The output residue from the subtractor is then combined in a second subtractor with the input from a second group of parallel connected cancellers using the same auxiliary channels. Each group of parallel connected cancellers and subtractor forms an iteration which reduces the residue of interference in the main channel. By providing a series of iterations, the cancellation obtainable can be improved along with an increase in system stability.

Abstract: An inductive, internally fed, ferrite-loaded antenna mounted at the geomecal center of a helicopter. The antenna is capable of transmitting in the 2-30 MHZ range with particularly good characteristics between 2.0-3.5 MHZ and employs the air frame as a radiating element. The radiation pattern is circular and extends for a radius greater than 200 mi. at an altitude of 300 feet.

Abstract: A signal processing arrangement which discriminates against large-amplitude nterference signals and in favor of information signals. Incoming signals are separated into a plurality of contiguous frequency channels whose total frequency coverage is the frequency band of interest. The signals in the individual channels are then amplitude limited so that relatively narrow band interference signals are limited while a wide band desired signal is not. The desired signal is then spectrally compressed to obtain a high amplitude signal while the remaining interference signals are spread and rejected.

Abstract: An improved gas-filled proportional counter which includes a resistor netk connected between the anode and cathode at the ends of the counter in order to eliminate "end effects".

Abstract: The adduct of hexamethylphosphoramide and a cyclophosphonitrilic chloride, PNCl.sub.2).sub.n.sup.. [(CH.sub.3).sub.2 N].sub.3 PO, useful for enhancing the fire retardancy of epoxy resins and a method for enhancing the fire retardancy of epoxy resins through the combination therewith.

Abstract: An optical connector to provide input-output coupling to an optical transsion line without interrupting completely the flow of optical radiation. An optically transparent dielectric block is inserted between portions of a fiber bundle transmission line. The block has one flat side along its length which is bonded to a second material having at least one flat side along its length cooperating with the flat side of the block. The input-output bundles are attached to the second material which has the same index of refraction as the first block.

Abstract: A method of enhancing the tensile strength of carbon fibers of laboratory d commercial materials. Carbon fibers are immersed at ambient temperatures in liquid bromine or bromine dissolved in a solvent within a chemical resistant container for a period of time, the bromine is then removed by flushing with an inert gas. The removed bromine may be recovered and reused by condensing the vapor; small traces of bromine may remain within the fiber. It has been found that the bromine treatment enhances the tensile strength of the treated fiber.

Abstract: A device for generating gas at a constant rate for raising a water profiler uring measurement of different parameters of the sea. The device is of a specific construction including a housing with end caps. LiH is placed into the housing and capped. A blasting cap ruptures one end cap permitting water to enter the housing. The water mixed with the LiH generates hydrogen gas and LiOH which provides lift for a profiler. A plurality of the gas generators are assembled onto a profiler for causing the profiler to ascend as many times as the number of devices carried by the profiler.

Abstract: This invention is directed to a test module for and method of testing integrated circuit connections (i.e., wire wrap, multilayer printed circuit boards, etc.) to determine whether or not the circuits are correctly wired and whether or not there are any short circuits or broken connections, as well as any other electrical problems. The system confirms the validity of the electrical interconnections by a visual comparison of the lighted light emitting diodes and the assembly plan; if the correct comparison is not made, an error in the manufacturing process is indicated. Failure of any of the expected light emitting diodes to light indicates missing or electrically bad connections; extra lighted light emitting diodes indicate extraneous connections or short circuits on the board.