Low reflectivity high efficiency input couplers for ghost mitigation

An augmented reality waveguide, comprising:

• a substrate;
• and
• an incoupler (IC) grating of slanted structures having a slant angle relative to a surface normal of the substrate, the slanted structures comprising:
• a substrate section disposed in the substrate, the substrate section having a substrate refractive index of at least 1.7;
• a first layer disposed on the substrate, the first layer having a first refractive index greater than the substrate refractive index;
• and
• a second layer disposed on the first layer, the second layer having a second refractive index less than the first refractive index;
• and
• a pupil expansion (PE) grating and an outcoupler (OC) grating, the PE grating and the OC grating at least including the first layer.

An augmented reality waveguide, comprising:

• a substrate;
• and
• an incoupler (IC) grating of slanted structures having a slant angle relative to a surface normal of the substrate, the slanted structures comprising:
• a substrate section disposed in the substrate, the substrate section having a substrate refractive index;
• and
• a grating material layer disposed on the substrate, the grating material layer having a refractive index greater than the substrate refractive index.