Design and Fabrication of Integrated Chirped Bragg Gratings for On-Chip Dispersion Control

A full description of the synthesis process for chirped and apodized integrated Bragg gratings is presented. Starting from a target complex reflectivity, the local Bragg and coupling coefficients are extracted and converted into physical grating parameters. Control over both the amplitude and group delay profiles of the devices may be exerted using a tapered sidewall relief grating design. Example devices, exhibiting bandwidths of up to 30 nm and both linear and quadratic group-delay profiles with up to a 13-ps span, are realized and compare well with their relative target functions. A passive measurement technique, employing a fully integrated Michelson interferometer, allows reconstruction of the fabricated gratings' amplitude and phase characteristics.