Reflectance Properties of Thue-Morse 1-D Dielectric Multilayers

Omnidirectional reflectivity is theoretically investigated in four Thue-Morse (T-M) structures S4, S5, S6 and S7. It is observed that the width of omnidirectional reflection region increases with the order of T-M multilayer i.e. from S4 to S7 generation and multiple photonic band gaps exist for both TE and TM modes due to self-similarity of T-M multilayers. It can also be found that multiple omnidirectional bandgaps (OBGs) exist in the higher generation non-periodic T-M dielectric structures due to the self-similarity in the internal structure. These structures can be used as dense optical filters, sensors and multifrequency laser cavities.