Fluorescence patterning through photoinduced migration of squaraine-functionalized azo derivatives

New photochromic and fluorescent dyes are formed by covalently attaching emissive squaraine units to azo moieties. Illumination of doped matrices by light interference fringes provokes the reversible migration of the dyes and the formation of fluorescent gratings, as shown schematically in the figure. The visualization of the gratings is performed by using fluorescence confocal microscopy.