科研之友
微信
新浪微博
Facebook
分享链接
摘要
A novel concept for introducing defects in 1D photonic crystal, to be used as filter for coarse wavelength division multiplexing-demultiplexing, and a methodology to design such filters are reported. The defects are introduced in the periodic structure through extension of dielectric layer in selective unit cells. Simulation results show that additional phase shifts, due to such extensions, open up precisely controlled narrowband transmission windows within the photonic band gap of the crystal. The transmission windows facilitate filtering of wavelength channels with spacing of about 20 nm as required for coarse wavelength division multiplexing (CWDM) systems. Our proposed photonic band gap (PBG) structures with engineered defects can serve as optical filters in multiplexer-demultiplexer (MUX-DEMUX) that exactly fulfill the specifications described by ITU-T Recommendation G.694.2, regarding channel allocation and inter-channel separation for CWDM systems. A detailed methodology to develop a filter for channels with proposed spacing is also described and validated for two ITU-T recommended channels. Due to inherent simplicity in the scheme of incorporating defects in the photonic crystal, the resulting structure is expected to offer better reproducibility and less fabrication hazards in comparison to the other photonic crystal based MUX-DEMUXs. Transmission characteristics of the proposed models are analyzed using transfer matrix approach.
- 出版日期2010-8
