Double optical grating

TL;DR: In this paper, a method and system for providing an optical grating is described, which consists of a top cladding, a core, a second plurality of discrete ridges forming a second grating, and a bottom cladding.

Abstract: A method and system for providing an optical grating are described. The optical grating is configured for light of a wavelength. The optical grating includes a top cladding, a first plurality of discrete ridges forming a first grating, a core, a second plurality of discrete ridges forming a second grating, and a bottom cladding. The first plurality of discrete ridges are spaced apart by a first pitch. The second plurality of discrete ridges are spaced apart by a second pitch. The core has a top side adjacent to at least a portion of the top cladding and a bottom side. The bottom cladding is adjacent to at least a portion of the bottom side of the core. The second grating resides between the bottom cladding and the core.