Patent ID: 8422841
Filing Date: 2013-04-16
Classification: G02B

Abstract:
1. An optical grating configured for light of a wavelength, the optical grating comprising: a top cladding; a first plurality of discrete ridges spaced apart by a first pitch forming a first grating, the first grating having a first idealized efficiency curve corresponding to the first pitch; a core having a top side and a bottom side, top side of the core being adjacent to at least a portion of the top cladding, the first grating residing between the top cladding and the core; a second plurality of discrete ridges spaced apart by a second pitch and forming a second grating, the second grating having a second idealized efficiency curve corresponding to the second pitch, the first grating and the second grating being configured such that the optical grating has an idealized efficiency curve corresponding to the sum of the first idealized efficiency curve and the second idealized efficiency curve and such that the idealized efficiency curve has a substantially flat central peak; and a bottom cladding adjacent to at least a portion of the bottom side of the core, the second grating residing between the bottom cladding and the core.