A new design of optical add/drop filters and multi-channel filters based on hexagonal PhCRR for WDM systems

In this research, using photonic crystal dielectric rods with a triangular lattice constant, a photonic crystal ring resonator (PhCRR) has been designed in order to be used in optical add/drop filters (ADF).Query Using the proposed hexagonal PhCRR with four different dropping waveguides, new ADFs have been designed and simulated. At a central wavelength of 1550.5 nm, the four proposed ADFs have an average transmission coefficient, a bandwidth, and a quality factor of 100%, 1.2 nm and 1330, respectively. The results obtained from these structures indicate the high flexibility of the proposed PhCRR and ADFs and their applicability in optical communication systems. Using the ADFs, two multi-channel drop filters have been designed in order to be used as optical MUX/DeMUX with a channel spacing of 4 nm which are suitable for wavelength division multiplexing systems. In this study, the plane wave expansion and finite difference time domain methods are, respectively, used, to characterize the photonic band gap and to investigate the optical behavior of the structures.