ABSTRACT
The photonic crystal is a key artificial material for realizing high density integrated optical circuits. One of the most promising techniques for the Maxwell solver is the finite-difference time-domain (FDTD) method based on the principles of multidimensional wave digital filters (MD-WDFs) because this method can be implemented easily and its algorithm is simple, stable, and suitable for massive parallel computation. This chapter shows that an algorithm of the FDTD method with the perfectly matched layers based on the MD-WDFs for discrete-time modeling of Maxwell’s equations. It analyses this method to photonic crystal waveguide devices and clarify their fundamental properties, the propagation constants and field profiles of straight waveguides. The chapter describes several circuit devices such as directional couplers and sharply bent waveguides, and their propagation characteristics. The chapter proposes a wavelength multiplexer/demultiplexer using directional couplers and right-angle bent waveguides.
