Real-time interferometry with photorefractive reference holograms.

Experimental results on real-time holographic interferometry using photorefractive iron-doped lithium niobate crystals to store the reference holograms are presented. Since the crystals are self-developing, precise repositioning of the reference hologram or in situ wet processing is not needed. With proper choice of experimental parameters it is found that the same reference hologram can be used for real-time processing of long sequences ( 10 min.) of input data with minimal degradation. The results obtained on visualization of heat-flow patterns from electronic chips illustrate the utility of this approach.