Novel concept for non-destructive readout method for photochromic rewriteable memory devices

A new concept for a non-destructive readout method for a photochromic rewriteable device is proposed based on a solvatochromic dye-linked photochromic dye system. From the theoretical molecular orbital calculations for the model compound, it was shown that the UV-Vis absorption band of the solvatochromic dye unit is sensitive to the conformation of the nearby photochromic unit. These calculations indicate that light corresponding to the UV-Vis absorption band of the solvatochromic dye unit can be used as the non-destructive readout light, since light in this region is found inactive to irradiation for achieving the photochromic reaction of the photochromic dye unit.