The present invention provides a method for detecting vibration information by receiving electromagnetic radiation reflected or emitted from a biological organism at a light amplitude modulation detector 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 preferably AC-coupled to isolate components relating to oscillations of the biological organism from components relating to ambient radiation, e.g. background sunlight. The isolated oscillations may then be digitized, stored, and subjected to processing such as a Fourier transform to generate outputs representative of frequencies of oscillation. This output can then be used for analysis of the target object.