A polygonal shape inverted "Y" optical beam splitter for splitting input light into two, equal intensity, homogenous light beams. A one-piece hollow tubular body is provided having a first, second, and third leg. Each leg has a polygonal cross-section and a highly reflective interior surface. The first leg is configured to receive an input light beam having an intensity and spectral content that is reflected within the first leg to provide a first leg output light beam. The first leg output light beam is split and reflected into a second and third leg to provide, after reflection in the second leg and the third leg, a second leg and third leg output light beam. Each of the second leg and third leg output light beam has a homogeneous top hat profile and an intensity equal to one half of the intensity of the input light beam.