Abstract: A system and method for detecting vibration information by receiving electromagnetic radiation reflected or emitted from a target object at a photodetector array to provide real-time imaging of the target object. The detected radiation may be visible light, infrared or ultraviolet radiation, and/or of other desired frequency ranges. The detected radiation is AC-coupled to isolate components relating to oscillations of the target object from components relating to ambient radiation, e.g. background sunlight, and is digitized, stored, and subjected to processing such as a Fourier transform to generate outputs representative of frequencies of oscillation, which can be used for analysis of the target object.

Abstract: A system and method for detecting vibration information by receiving electromagnetic radiation reflected or emitted from a target object at a photodetector array to provide real-time imaging of the target object. The detected radiation may be visible light, infrared or ultraviolet radiation, and/or of other desired frequency ranges. The detected radiation is AC-coupled to isolate components relating to oscillations of the target object from components relating to ambient radiation, e.g. background sunlight, and is digitized, stored, and subjected to processing such as a Fourier transform to generate outputs representative of frequencies of oscillation, which can be used for analysis of the target object.

Abstract: There is disclosed herein a technique for detecting and/or identifying a particular object from which electromagnetic radiation is emitted or reflected at an intensity which fluctuates in accordance with a frequency pattern unique to that object. In accordance with the technique, the fluctuating electromagnetic radiation is detected by suitable equipment which can operate across an optical bandwidth extending from the ultraviolet (200 nm) to the infrared (14 micrometers) spectrum. The detected electromagnetic radiation is converted to an electrical signal having the same unique frequency pattern as the electromagnetic radiation itself. This electrical signal, its frequency pattern serving as an identifying signature of the object in question, is used to detect, track, and/or identify the object.

Abstract: Method and apparatus for limiting optical radiation to an optical sensor are disclosed for protecting the sensor against damage from high intensity optical radiation. A fixed electric field is established between a pair of spaced electrodes by connection of the electrodes to a DC voltage source. Small solid particles oscillate back and forth in the electric field between the electrodes. Incident optical radiation is focused at a focal plane at the oscillating solid particles, and energy transmitted through the oscillating particles is focused at the optical sensor. The transmittance of the particle-containing space is substantially constant for incident optical radiation intensity up to a threshold level below which the sensor is undamaged by the radiation.

Abstract: A nonlinear optical fluid with radiation-absorbing small particles uniformly suspended in the fluid. For radiation below a threshold value, radiation passes through with slight attenuation. Above the threshold, only a limited level of radiation is passed, the limit being below the damage level of a sensitive optical detector.