Eyepiece for virtual, augmented, or mixed reality systems

An eyepiece for a virtual reality, augmented reality, or mixed reality system, the eyepiece comprising:

• a waveguide substrate that is at least partially transparent;
• an input coupler grating formed on or in the waveguide substrate and configured to couple at least one input light beam that is externally incident on the input coupler grating into at least a first guided light beam that propagates inside the waveguide substrate;
• a first orthogonal pupil expander (OPE) grating formed on or in the waveguide substrate and configured to divide the first guided light beam from the input coupler grating into a plurality of parallel, spaced-apart light beams;
• a first spreader grating that receives the light beams from the first OPE grating and spreads their distribution, the first spreader grating comprising diffractive features oriented at approximately 90° to diffractive features of the first OPE grating;
• and
• an exit pupil expander (EPE) grating formed on or in the waveguide substrate and configured to re-direct the light beams from the first OPE grating and the first spreader grating such that they exit the waveguide substrate.