Patent ID: 7535647
Filing Date: 2009-05-19
Classification: G02B

Abstract:
1. A beam splitter for splitting wavelengths of electromagnetic radiation, said beam splitter comprising: an optically transmissive member including first and second optically transmissive elements, both of said elements having the same optical path lengths, said first element having a first surface, said second element having a second surface which mates with said first surface, the interface between said first and second mating surfaces defining an internal surface; said internal surface being divided into first, second and third zones; said first zone having a first coating which, for said wavelengths, is substantially 100% reflective; said second zone having a second coating which, for said wavelengths, is partially transmissive and partially reflective; said third zone having an anti-reflective coating being substantially 100% transmissive; and said second zone being between said first and said third zone.