Abstract: A large area nuclear detection system with high resolution includes a sensor formed of scintillating optical fibers and a remotely located detector comprising at least a pair of microchannel plate photomultiplier tubes, with the sensitive area of the sensor being many times the area of the detectors. Two linear arrays of optical fibers are arranged orthogonally to define a sensor matrix of rows and columns of fibers. Nuclear radiation from a particle at the sensor is converted to optical energy by the sensor. A microchannel PMT is connected with each array for measuring the optical energy output of the fibers thereof to determine the row and column location of the nuclear particle in accordance with the quantity of energy received from the fibers. Thus, nuclear radiation can be detected over a large area with a high degree of accuracy and resolution.

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 high intensity laser radiation protection system is characterized by the use of a thin film reflector structure which is operable to terminate transmission of optical signals to an optical sensor in response to high intensity laser radiation. The thin film reflector includes a glass substrate having a thin layer of radiation absorption material applied thereto with a thin layer of reflective metal film applied to the absorption layer. The absorption layer has a low melting and vaporization temperature, and the layer of metal film has a thickness affording passage of a limited amount of laser radiation to the absorption layer. When laser radiation having a predetermined intensity is received by the absorption layer, the absorption layer rapidly melts and destroys the metal film layer to terminate optical transmission to the optical sensor, thereby preventing damage to the sensor from the laser radiation.

Abstract: An improved wire detection and avoidance system for helicopters is characterized by the use of a solid state laser transmitter which emits radiation in the near infrared wavelength region. Using either a beam dividing device or a plurality of laser diode arrays, separate laser beam lobes are generated which are passed through optical lenses for deflection in slightly different directions to define a field of coverage. A wire obstacle in the field of coverage intercepts one or more of the lobes and reflects return signals thereof to a receiver detector array. The return signals are compared with the transmitted laser lobes, with the difference therebetween being a function of the range between the obstacle and the helicopter. The range information is displayed to the pilot who then takes evasive action to avoid striking the obstacle.

Abstract: A method and apparatus for non-destructive monitoring of the performance parameters of a photodiode prior to integration into a focal plane array are characterized by the use of electron tunneling techniques. The photodiode under test is illuminated with infrared radiation to generate a current therein. The current within the photodiode is measured by a contactless tunnel current probe. The measured current is electrically processed to determine the dynamic resistance and responsitivity of the photodiode in order to evaluate its performance. The apparatus can also be used for testing integrated circuits in the active mode at a plurality of locations.

Abstract: An optical fiber sensitive to nuclear radiation includes a thin filament core formed of a plastic scintillator material which scintillates in the presence of nuclear radiation. An optical cladding material is provided around the optical fiber. A second fiber is connected to the optical fiber for efficiently transmitting the scintillating light from the optical fiber to a radiation detector.

Abstract: A system for simultaneously detecting nuclear radiation and pressure combines light signals from a radiation sensitive scintillating optical fiber with light signals from a pressure sensitive optical fiber. The scintillating fiber is coupled to a light transmitting optical fiber for long distance light transmission to a detector unit such as a photomultiplier tube. The concurrent detection of radiation and pressure of radiation and pressure is used to trigger an alarm signal.

Abstract: An optical fiber security system having two optical fiber strands each with a light transmission and detection capability such that a deformation as is caused by unwanted intrusion of one of the strands with respect to the other is detected.

Abstract: An improved laser apparatus is provided wherein a laser and a pump source comprising an array of GaAs or GaAlAs light emitting laser diodes or of excimer fluorescors or lasers which emits a large cross section beam of generally collimated pumping radiation are coupled by flux concentrating means comprising a compound parabolic concentrator.

Abstract: A nuclear radiation detection system for remote monitoring of movement of nuclear material over a road or highway. Nuclear fiber sensors, which may be several meters long, are covertly positioned in at least two monitoring points, such as buried shallowly under the roadway or hung from a tunnel wall, along the path which a nuclear source may be clandestinely moved. These fiber sensors are individually connected, by an epoxy glue, to individual transmitting optical fibers. Movement of a nuclear radiation source in close proximity to the fiber sensors at the two or more monitoring points produces an optical signal which exceeds a preestablished threshold. These optical signals travel through the transmitting optical fibers, which may be about 1 kilometers long, to a electronic system comprised of a microprocessor controlled signal detecting, signal processing and even data storage means. The optical fibers and electronic system are also selectively hidden from view for security reasons.