Waveguide display having phase compensation layers

A display comprising:

• a waveguide configured to propagate light;
• a substrate on the waveguide, the substrate having a first region and a non-diffractive region that laterally abuts the first region at a boundary;
• a surface relief grating (SRG) in the first region of the substrate, wherein a first portion of the light is incident upon the SRG and a second portion of the light is incident upon the non-diffractive region;
• and
• a layer overlapping the non-diffractive region of the substrate, wherein the layer has a thickness and a refractive index configured to match a phase of the second portion of the light to a phase of the first portion of the light.

A display comprising:

• a waveguide configured to propagate light;
• a substrate on the waveguide, the substrate having a first region and a second region that laterally meets the first region at a boundary;
• a first surface relief grating (SRG) in the first region of the substrate, wherein a first portion of the light is incident upon the first SRG;
• a second SRG in the second region of the substrate, wherein a second portion of the light is incident upon the second SRG;
• and
• a layer overlapping the second region of the substrate, wherein the layer has a thickness and a refractive index configured to match a phase of the second portion of the light to a phase of the first portion of the light.