Modeling of chirped pulse propagation through a mini-stop band in a two-dimensional photonic crystal waveguide

The finite-difference time-domain (FDTD) and frequency-domain finite-element (FE) methods are used to study chirped pulse propagation in 2D photonic crystal (PhC) waveguides. Chirped pulse FDTD has been implemented, which allows the study of pulse propagation in a direct way. The carrier wavelength of the pulse is swept across the bandwidth of a mini-stop-band (MSB) feature, and pulse compression behavior is observed. Both round-hole and square-hole PhC waveguides are studied, with the latter giving increased pulse compression. A group-delay analysis is then used to understand the compression behavior, and this shows how the fast-light regime that occurs within the MSB plays an important role in the observed pulse compression.