We propose a multiple exposure specklegram by using an optical system whose
multiple aperture pupil changes between exposures. In particular, we analy
ze experimentally two arrangements and we show that it is possible to store
the required information by employing a minimum number of registers if an
adequate selection of the pupil is done. We study the effect of the decorre
lation (among the stored speckle pattern) introduced by chaning the multipl
e aperture pupil arrangements between exposures. The fundamentals and the r
elative benefits of the new scheme proposed are discussed on the basis of a
fringe visibility analysis. (C) 2000 Published by Elsevier Science B.V.