High-efficiency filters for photonic integrated networks: a brief analysis

Abstract

In this paper, wide band pass filters (BPFs) and narrow band stop filters (BSFs) based on photonic crystals with large tunability have been achieved by using the resonance effect of crystal rings. The crystal structure (pillars) situated over the substrate of air is silicon, with permittivity contrast of 1/11.7 and a 2D lattice of the hexagonal system with appropriate permittivity contrast value of 1/8.9. The proposed structure is designed for the waveguide width 0.2 µm and wafer dimension 20 µm × 20 µm. The diamond ring square pillar filter possesses the highest quality factor (QF) of 1066.429 for 1493 nm drop signal with a narrow bandwidth of 1 nm. The hexagonal ring circular pillar filter acquires the highest QF of 134.5133 among the designed BPFs. The wider bandwidth of 100.4 nm is achieved by the diamond ring elliptical pillar BPF in the range of 1800–1900 nm. A bi-periodic circular pillar BSF is obtained with the large QF of 702.2727 and with the narrow bandwidth of 1.8 nm. Both the BPFs and the BSFs work at the second and third windows of an optical system, making the filters suitable for wavelength division multiplexing and networking applications.