Propagation of Flat-top Optical Pulses in Defective Photonic Band Gap

In this article, we provide a theoretical investigation into the reshaping of flat-top pulses in a one-dimensional, homogeneous, isotropic, finite-size photonic crystal with two defect layers. we use fourier transform to find frequency and time spectra, and transfer matrix to determine transmission spectra to find the average duration and power of the output pulse. the pulses with a carrier frequency near the defect mode center and a wide frequency spectrum, undergo the most significant reshaping. reshaping is strongest for narrow pulses with a carrier frequency at defect mode peaks. the maximum power and duration of the output pulse of a spectrally narrow pulse are all proportional to the pulse duration and exhibit extremes at the frequencies of the defect mode peaks. the power and average duration of a spectrally wide pulse's output pulse are not affected by the carrier frequency.