Waveguide grating filters for dispersion compensation and pulse compression

Dispersion compensation and pulse compression are theoretically demonstrated using aperiodic waveguide gratings. The gratings are designed to have both a flat amplitude and a quadratic phase response over the pulse bandwidth. This results in nearly transform-limited compressed pulses. The appropriate waveguide grating parameters are obtained by applying the Gel´fand-Levitan-Marchenko inverse scattering method to the coupled mode equations which describe propagation. The technique is illustrated by designing an aperiodic grating which compresses a 60-ps pulse by a factor of three. Limitations and possible extensions of the general method are discussed