Multiple defect characterization in finite-size waveguiding photonic bandgap structures

A powerful and efficient model recently proposed by the authors based on the leaky mode propagation method is used to characterize photonic bandgap structures incorporating multiple defects, having arbitrary shape and geometrical parameter values. The importance of the defect-mode characterization in photonic bandgap materials is due to the intensive use of defects for light localization to design very promising optical devices. This paper provides a new, efficient method to model defects in waveguiding, finite-size photonic bandgap devices and analytical and closed-form expressions for the reflection and transmission coefficients and out-of-plane losses,which is very useful and easily implemented under any operating conditions. Moreover, the method has been applied to examine the capabilities of waveguiding photonic bandgap devices in dense wavelength division multiplexing filtering applications. Therefore, the design of two optical filters for such applications has been carried out and optimal design rules have been drawn using the new model.