A photoinduced transition in an azobenzene-containing liquid crystal leads to a phase that does not exist in the thermal cycle. The smectic A phase is induced and stabilized only in the presence of UV light, producing fan-shaped focal conic textures typical of the SmA phase, as observed by polarized-light microscopy (see Figure). This dynamic self-assembly is explained by photoinduced nanophase segregation and a frustrated spin-gas model.