An image display system, comprising: a waveguide (310, 510, 780, 850, 910); an optical device (550, 620, 700, 721, 722, 760) comprising a first prism (562, 621, 701, 761) and a second prism (561, 622, 702, 762), wherein the first prism (562, 621, 701, 761) and the second prism (561, 622, 702, 762) are right triangle prisms, a first surface (552, 623, 711, 771) of the first prism (562, 621, 701, 761) and a second surface (554, 624, 712, 772) of the second prism (561, 622, 702, 762) being disposed in parallel and adjacent to each other and at an oblique angle to the waveguide (310, 510, 780, 850, 910), the first surface (552, 623, 711, 771) being partially reflective and the second surface (554, 624, 712, 772) being substantially totally reflective, wherein the optical device (550, 620, 700, 721, 722, 760) is configured for receiving an incoming light beam (520, 611, 710, 920) and providing a plurality of input beamlets (521, 630, 730) to the waveguide (310, 510, 780, 850, 910), each input beamlet (521, 630, 730) being derived from a portion of the incoming light beam (520, 611, 710, 920), the input beamlets (521, 630, 730) being offset spatially; wherein the waveguide (310, 510, 780, 850, 910) is configured for: receiving the plurality of input beamlets (521, 630, 730); propagating the plurality of input beamlets (521, 630, 730) by total internal reflection; and outputting multiple groups of output beamlets (330, 531, 532, 533, 534), each group of output beamlets (330, 531, 532, 533, 534) including a portion of each of the plurality of input beamlets (521, 630, 730) propagating in the waveguide (310, 510, 780, 850, 910) by total internal reflection. a waveguide (310, 510, 780, 850, 910); an optical device (550, 620, 700, 721, 722, 760) comprising a first prism (562, 621, 701, 761) and a second prism (561, 622, 702, 762), wherein the first prism (562, 621, 701, 761) and the second prism (561, 622, 702, 762) are right triangle prisms, a first surface (552, 623, 711, 771) of the first prism (562, 621, 701, 761) and a second surface (554, 624, 712, 772) of the second prism (561, 622, 702, 762) being disposed in parallel and adjacent to each other and at an oblique angle to the waveguide (310, 510, 780, 850, 910), the first surface (552, 623, 711, 771) being partially reflective and the second surface (554, 624, 712, 772) being substantially totally reflective, wherein the optical device (550, 620, 700, 721, 722, 760) is configured for receiving an incoming light beam (520, 611, 710, 920) and providing a plurality of input beamlets (521, 630, 730) to the waveguide (310, 510, 780, 850, 910), each input beamlet (521, 630, 730) being derived from a portion of the incoming light beam (520, 611, 710, 920), the input beamlets (521, 630, 730) being offset spatially; wherein the waveguide (310, 510, 780, 850, 910) is configured for: receiving the plurality of input beamlets (521, 630, 730); propagating the plurality of input beamlets (521, 630, 730) by total internal reflection; and outputting multiple groups of output beamlets (330, 531, 532, 533, 534), each group of output beamlets (330, 531, 532, 533, 534) including a portion of each of the plurality of input beamlets (521, 630, 730) propagating in the waveguide (310, 510, 780, 850, 910) by total internal reflection. receiving the plurality of input beamlets (521, 630, 730); propagating the plurality of input beamlets (521, 630, 730) by total internal reflection; and outputting multiple groups of output beamlets (330, 531, 532, 533, 534), each group of output beamlets (330, 531, 532, 533, 534) including a portion of each of the plurality of input beamlets (521, 630, 730) propagating in the waveguide (310, 510, 780, 850, 910) by total internal reflection.