Coupler utilizing a diffractive optical element for coupling light to an optical waveguide

摘要

An apparatus for coupling light from a light source into an optical waveguide having an entrance aperture for receiving light to be transmitted by the waveguide. The entrance aperture has a numerical aperture that may vary over the aperture. The apparatus includes an optical element that conditions the light from the light source and a diffractive optical element. The diffractive optical element generates a plurality of light spots from the light source. The light from each light spot enters the entrance aperture of the waveguide at a different point on the entrance aperture. Each of the light spots has a numerical aperture that is less than the numerical aperture of the entrance aperture at the point on the entrance aperture at which the light from that light spots enters the entrance aperture.