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.