Edge enhancement, contrast reversal and logic operations using beam fanning in a photorefractive iron-doped barium tltanate crystal

摘要

We investigate the dynamics of beam fanning in: a photorefractive barium titanate crystal at different, wavelengths and with a mixed-polarization state of the input beam. The investigations reveal a remarkable difference in thebehaviours at different wavelengths. This is further used to advantage for edge enhancement and image intensity inversion processes. Incoherent erasure to control the beam fanning has been exploited to perform some of the logic operations. The simplified geometry, ease of alignment and low input intensit-ies involved are some features of the present work.