Reconfigurable photonic crystal filter with high transmission Covering E-L bands and potential for DWDM applications

A reconfigurable photonic crystal (PhC) filter is proposed for Dense Wavelength Division Multiplexing (DWDM) applications across the E, C, S, and L bands, offering a high-quality factor (QF) and excellent transmission efficiency. The structure has a point defect resonator whereby changing the radii of coupling and center rods allows tuning over several resonant frequencies. This flexibility supports several wavelengths, so optimizing optical communication networks. The variation in rod radii lets one trade-off between QF and transmission efficiency, so enabling fine-tuning for particular performance requirements. Using a single cavity resonator, the tuned 2D Channel Drop Filter (CDF) guarantees a compact and reconfigurable construction. Its operating wavelengths are resonant ones ranging from 1429 nm to 1594 nm. Under ideal conditions, simulation results show a QF range of 200 to 420 with transmission efficiency reaching 100 %. This small solution provides flexibility while keeping high performance, so meeting the needs of contemporary DWDM systems.