An optical device includes a light source configured to provide illumination light and a waveguide. The waveguide has an input surface, an output surface distinct from and non-parallel to the input surface, and an output coupler. The waveguide is configured to receive, at the input surface, the illumination light provided by the light source and propagate the illumination light via total internal reflection. The waveguide is also configured to redirect, by the output coupler, the illumination light so that the illumination light is output from the output surface for illuminating a spatial light modulator.