Dual light guide grating-based backlight and electronic display using same

A three-dimensional (3D) electronic display comprising:

• a first light guide and a second light guide;
• a redirection coupler configured to couple and redirect a guided light beam from the first light guide into the second light guide;
• an array of multibeam diffraction gratings at a surface of the second light guide, a multibeam diffraction grating of the array being configured to diffractively couple out a portion of the redirected light beam guided within the second light guide as plurality of coupled-out light beams having different principal angular directions representing different views of the 3D electronic display;
• and
• a light valve array configured to modulate the coupled-out light beams, the modulated coupled-out light beams representing pixels corresponding to the different views.

A method of grating-based backlight operation employing dual light guides, the method comprising:

• guiding light in a first plate light guide at a non-zero propagation angle as a guided light beam, the guided light beam being collimated;
• redirecting the guided light beam using a redirection coupler into a second plate light guide as a redirected guided light beam;
• and
• diffractively coupling out a portion of the redirected guided light beam using a diffraction grating at a surface of the second plate light guide to produce a coupled-out light beam directed away from the second plate light guide at a predetermined principal angular direction.