Chapter 10 - Photonic crystal-based optical devices for photonic intergraded circuits

Abstract

Photonic crystals (PCs)-based optical devices are playing an important role for photonic integrated circuits for proving significant functionality. In this chapter, we initially presented the introduction, history, and the types of PCs. As two-dimensional PC-based optical devices are meeting the requirements of photonic integrated circuits, the band diagram, gapmap, impact of defects, and reported devices based on two-dimensional PC are presented. Then the numerical methods, such as, plane wave expansion method and finite difference time domain method are discussed. The operating principle and the requirement of PC-based demultiplexer, demultiplexer for ITU-T G 694.1 dense wavelength division multiplexing (DWDM) system along with tapering mechanism are described. The hybrid demultiplexer designed to support multifunction in the single lattice. The DWDM device is designed to work in 25 GHz/0.2 nm and 50 GHz/0.4 nm in the square lattice and triangular lattice. Taper design demultiplexer is designed to reduce the insertion loss, and coupling loss between single mode fiber and PC device. The different design like triangular, rectangle, butt coupling is designed along the DWDM demultiplexer. However, triangle taper provides the coupling efficiency of over 100%. Finally, the applications of PC-based optical devices are explored. Such structures can potentially provide a good alternative to the traditional demultiplexer, as one of the key contributors to the emerging low-power nanophotonics technology and photonic integrated circuits.