An optical collimator comprising: an optical waveguide having a first end comprising a first light interface; a second end opposite the first end; a viewing surface comprising a second light interface extending at least partially between the first end and the second end and having a first critical angle of internal reflection with respect to a normal of the viewing surface; wherein the first end of the optical waveguide is a thin end and the second end of the optical waveguide is a thick end; a back surface opposing the viewing surface, the back surface being configured to be reflective to internally incident light at the first critical angle of internal reflection; and an end reflector arranged at the second end of the optical waveguide, wherein the end reflector comprises a faceted lens structure comprising a plurality of facets (530, 540) angled to cause a majority of the viewing surface to be uniformly illuminated when uniform light is injected into a first end and also to cause a majority of the injected light to exit the viewing surface, wherein the plurality of facets (530, 540) of the faceted lens structure of the end reflector includes a plurality of facets facing the viewing surface and a plurality of facets facing the back surface, each facet facing the viewing surface being positioned adjacent to a facet facing the back surface, characterized in that each facet facing the viewing surface forms an angle relative to a normal of a surface of the end reflector of three-eighths of a difference between 90 degrees and the first critical angle, wherein each facet facing the back surface forms an angle relative to a normal of a surface of the end reflector equal to three-eighths of a difference between 90 degrees and the first critical angle. an optical waveguide having a first end comprising a first light interface; a second end opposite the first end; a viewing surface comprising a second light interface extending at least partially between the first end and the second end and having a first critical angle of internal reflection with respect to a normal of the viewing surface; wherein the first end of the optical waveguide is a thin end and the second end of the optical waveguide is a thick end; a back surface opposing the viewing surface, the back surface being configured to be reflective to internally incident light at the first critical angle of internal reflection; and an end reflector arranged at the second end of the optical waveguide, wherein the end reflector comprises a faceted lens structure comprising a plurality of facets (530, 540) angled to cause a majority of the viewing surface to be uniformly illuminated when uniform light is injected into a first end and also to cause a majority of the injected light to exit the viewing surface, wherein the plurality of facets (530, 540) of the faceted lens structure of the end reflector includes a plurality of facets facing the viewing surface and a plurality of facets facing the back surface, each facet facing the viewing surface being positioned adjacent to a facet facing the back surface, a first end comprising a first light interface; a second end opposite the first end; a viewing surface comprising a second light interface extending at least partially between the first end and the second end and having a first critical angle of internal reflection with respect to a normal of the viewing surface; wherein the first end of the optical waveguide is a thin end and the second end of the optical waveguide is a thick end; a back surface opposing the viewing surface, the back surface being configured to be reflective to internally incident light at the first critical angle of internal reflection; and an end reflector arranged at the second end of the optical waveguide, wherein the end reflector comprises a faceted lens structure comprising a plurality of facets (530, 540) angled to cause a majority of the viewing surface to be uniformly illuminated when uniform light is injected into a first end and also to cause a majority of the injected light to exit the viewing surface, wherein the plurality of facets (530, 540) of the faceted lens structure of the end reflector includes a plurality of facets facing the viewing surface and a plurality of facets facing the back surface, each facet facing the viewing surface being positioned adjacent to a facet facing the back surface, characterized in that each facet facing the viewing surface forms an angle relative to a normal of a surface of the end reflector of three-eighths of a difference between 90 degrees and the first critical angle, wherein each facet facing the back surface forms an angle relative to a normal of a surface of the end reflector equal to three-eighths of a difference between 90 degrees and the first critical angle.