Superluminal Tunneling and Negative Group Delay in Layered Bragg Structures

Bragg structures with distortion of periodicity are considered. Effects of wave scattering are theoretically investigated in wide frequency band. Methods of characteristic matrices and Fourier wave decomposition are used for obtaining frequency and time dependencies of reflected and transmitted wave pulses. Magnitudes and phases of scattered fields are analyzed. Phenomena of anomalous behavior of group delay (superluminal and negative ones) are observed for Bragg structures with different type of distortions