An illumination system includes a light source, an optical waveguide that has a proximal end and a distal end such that the proximal end is arranged to receive light from the light source and the distal end is suitable to illuminate an object of interest; and an optical coupler constructed and arranged to couple light from the light source into the optical waveguide. The optical coupler includes a reflective surface that reflects at least some light diverging from the light source to be coupled into the optical waveguide.