Diffractive Grating Coupler And Method

Abstract

The present invention entails a volume grating for use as an optical coupler and method for creating the same which comprises a predetermined surface grating pattern having a decreasing surface grating period along a waveguide light propagation direction in the volume grating with a plurality of slanted grating fringes having a variable slant angle along the waveguide light propagation direction to focus coupled light in a first dimension with a predetermined light intensity profile along a grating-cover interface plane of the volume grating. In addition, the predetermined surface grating pattern further includes an increasing radius of curvature along the waveguide light propagation direction to focus the light in a second dimension. The present invention further comprises a system and method for designing the volume grating, as well as a system and method for designing an apparatus for fabricating the volume grating.