title: Detailed analysis of the influence of structure length on pulse propagation through finite-size photonic crystal waveguides.
abstract: We present a detailed analysis of the influence of the finite length of a photonic crystal (PhC) waveguide on its final response to pulses propagation. The analyzed PhC waveguide is accessed by conventional dielectric waveguides and the lack of a perfect coupling between them produces reflections at the interfaces, leading to the appearance of several output pulses at the end of the PhC waveguide. If the length of the PhC waveguide is short enough these repetitions overlap and the parameters that define the total output pulse (mainly amplitude, temporal width, time delay and group velocity) vary significantly. An oscillatory behavior of these parameters is observed when the length of the PhC waveguide is modified. A theoretical model has been used to achieve each cavity generated pulse at the output of the PhC waveguide. The unique parameters needed for these calculations are the propagation constant of the PhC waveguide and the transmission and reflection coefficients at each interface. Numerical simulations based on the eigenmode expansion method are used to obtain these parameters. The time and resources required to calculate the output pulse with this method are significantly reduced in comparison with FDTD simulations and the results are proved to be quite accurate.
authors.forename: Jaime
authors.initials: J
authors.lastname: García
authors.forename: Pablo
authors.initials: P
authors.lastname: Sanchis
authors.forename: Javier
authors.initials: J
authors.lastname: Martí