Showing 2 results for Fourier Transform
Dr. Mohsen Hatami, Ms. Elham Yousefi,
Volume 7, Issue 2 (8-2013)
Abstract
In this study, a new numerical method is introduced to obtain the exact shape of output pulse in the chalcogenide fiber Bragg grating (FBG). A Gaussian pulse shape with 173 ps width is used as an input pulse for lunching to a 6.6 mm nonlinear FBG. Because of bistable and hysteresis nature of nonlinear FBG the time sequence of each portion of pulse is affected the shape of output pulse. So we divide the pulse to leading and trailing portion in time. By using bistability curve and Fourier transformation, the exact shape of output pulse is simulated. In comparison of non-unique solution for output pulse in the previous papers, the results of this study have an optional merit.
Sarah Bolandnazar, Samad Roshan Entezar,
Volume 17, Issue 1 (1-2023)
Abstract
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.
