An optical wave guide. The guide includes a body with a cross section that defines a polygon, preferably a hexagon. The proximal end of the body optically couples to an optical source (e.g. an optical fiber or light source) with an initial distribution. The wave travels through the body to the distal end whereby the distribution becomes a top hat distribution. In another preferred embodiment a bundle of optical fibers is coupled to the distal end. Additionally, the guide may include a coupler to align the source and the bundle with the body. In yet another preferred embodiment, the length of the body is at least about 6 times the width of the cross section. In another preferred embodiment, a method of splitting a wave is provided. The method includes passing an electromagnetic wave through a wave guide with a hexagonal cross section.