Narrowband reflection from integrated Bragg gratings with corrugations on long side structures

Abstract

An alternative approach to realize CMOS-compatible integrated Bragg gratings is proposed and implemented in this work to allow flexible control of the reflection response. To enable weak grating coupling strength in fully-etched waveguide, we employ corrugations on long side waveguides in the proposed cladding-modulated waveguides, leading to a measured reflection bandwidth of only 0.44 nm and a peak reflectivity of 96%. This grating design is relatively insensitive to the grating width variation, so within 1nm Bragg wavelength variation is also observed.