Abstract

Gratings implemented on silicon-on-insulator (SOI) structures have been used for waveguide coupling^[1] Gratings can also form the end mirrors of DFB and DBR lasers. Recently, channel dropping filters have been fabricated in silicon from gratings with a quarter wave shift^[2] Such resonant gratings transmit one frequency but reflect the others that fall within the “stop band” or band gap. In order for the stop bands to cover the 40 nm spectrum of erbium amplifers, deep gratings or large index modulations are needed. As the grating strength increases, light tends to radiate into the substrate.

© 1996 Optical Society of America