Mixed-reality waveguide combiner with reduced world-side leakage

A head-mounted display (HMD) device wearable by a user and supporting a mixed-reality experience including viewing virtual images from a virtual world that are combined with real-world images of objects in a real world, comprising:

• a display engine configured for producing virtual images;
• a see-through waveguide combiner through which the user can view the physical world and on which the virtual images are rendered within a field of view (FOV) of the HMD device, the see-through waveguide combiner comprising a substrate;
• a foundation layer disposed on the substrate, the foundation layer having a first refractive index value;
• and
• an output-coupling diffractive optical element (DOE) disposed on the foundation layer, the output-coupling DOE comprising surface relief grating (SRG) structures and a residual layer having a second refractive index value that is different from the first refractive index value.

A method for fabricating a surface relief grating (SRG) that out-couples virtual images over views, by a user, of a real world, the method comprising:

• providing a see-through substrate;
• configuring an inkjet system for forming resin films on the substrate, the inkjet system using two or more different inkjet-printable resins each having a different refractive index;
• operating the inkjet system to dispense the different inkjet-printable resins in a patterned array on the substrate in resin films;
• using the dispensed resin films to form a residual layer having a gradient thickness on the substrate;
• and
• using the dispensed resin films to create initial diffractive grating structures having a gradient refractive index on the substrate.