Dynamic Properties of Laser Speckles on Images Transmitted Through an Image Fibre-bundle
Nobukatsu Takai, Shunpei Kimura, Toshimitsu Asakura · Journal of Modern Optics · 1989
The statistical properties of time-varying laser speckles appearing on an image transmitted through an image fibre-bundle are studied experimentally and theoretically. The effect of defocusing on a stage of observation is investigated in relation to the stationarity of the detected speckle intensity. It is shown that a large amount of defocusing produces a stationary speckle field for which the correlation function of the speckle intensity variation is obtained in a stable form. This allows a system for monitoring the velocity of moving objects using an image fibre-bundle to be developed.