Abstract: An optical vibration analyzer is disclosed in which a fiber optic probe collects back scattered light from a vibrating surface illuminated with non-coherent light. The probe is positioned very close to the vibrating surface such that the amount of light scattered back into the fiber optic probe varies with the instantaneous relative separation between the probe and vibrating surface. A photo-diode detects the varying average intensity of light received by the probe and generates a light intensity signal which is amplified to a usable level. The back scattered light is very small in comparison with ambient light and other non-correlated noise from which it is extracted. Accordingly, vibrations in the observed surface are excited by a sweep oscillator and the received signal is processed through a tracking filter locked to the sweep oscillator. The filtered output is monitored and varies directly with the vibration amplitude of the surface.