The current status of substituted rigid rod-like polymers is reviewed with respect to applications in photonic devices, These polymers facilitate the control of microscopic order as,yell as the fabrication of devices with a predictable and defined molecular alignment, Special emphasis is placed on the correlation between these structural parameters and macroscopic quantities such as nonlinear optical susceptibilities and optical anisotropy, Rigid rod-like polymers are shown to be promising for the design of special devices, although their potential has not so far been sufficiently exploited.