Optical aperture multipliers having a rectangular waveguide

An optical aperture multiplier comprising:

• a first optical waveguide having a first pair of parallel faces including a first face and a second face, and a second pair of parallel faces including a third face and a fourth face, the pairs of parallel faces together forming a rectangular cross-section, wherein a partially reflective surface is associated with, and is parallel to, the second face;
• and
• a second optical waveguide having a plurality of faces including a third pair of parallel faces, the second optical waveguide being optically coupled with the first optical waveguide at an interface between the second face and one of the faces of the second optical waveguide, wherein a light redirecting arrangement is associated with a first region of the second optical waveguide and an optical coupling-out configuration is associated with a second region of the second optical waveguide,
• wherein the optical coupling, the partially reflective surface, the light redirecting arrangement, and the optical coupling-out configuration are configured such that, when light corresponding to an image is coupled into the first optical waveguide the light advances by four-fold internal reflection along the first optical waveguide, with a proportion of intensity of the light transmitted at the partially reflective surface so as to be coupled into the first region of the second optical waveguide, and propagates within the first region of the second optical waveguide by internal reflection at the third pair of parallel faces, with a proportion of intensity of the light deflected by the light redirecting arrangement so as to be redirected into the second region of the optical waveguide, and propagates within the second region of the second optical waveguide by internal reflection at the third pair of parallel faces, with a proportion of intensity of the light propagating within the second region of the second optical waveguide deflected out of the second optical waveguide by the optical coupling-out configuration.