Subtraction digital holography

Overlapping of the desired (first-order) and undesired (zero-order) terms originating from the recorded primary-fringe patterns in digital holography is a problem without a real-time solution. We propose a procedure for suppressing the zero-order disturbance that is realizable in real time. The procedure is based on the stochastic change of the speckles in the primary-fringe patterns and on the subtraction of two such subsequent patterns. The theoretical description of the procedure is given and experimental results presented. (C) 2003 Optical Society of America.