Patent ID: 8630043

Claim:
An optical device comprising: first, second, third and fourth prisms, each having respective first, second and third facets; the second facet of the second prism being bonded to the second facet of the first prism; the third facet of the third prism being bonded to the third facet of the second prism; and the second facet of the fourth prism being bonded to the second facet of the third prism; a first dichroic filter disposed on the first facet of the second prism, the first dichroic filter configured to reflect light of a first color and to pass light of a second color; and a second dichroic filter disposed on the first facet of the fourth prism, the second dichroic filter configured to reflect light of the first and second colors and to pass light of a third color; wherein the first, second and third prisms are arranged, configured and bonded such that: light of the first color entering the device through the first prism third facet is reflected by the first prism first facet through the first and second prism second facets to the first dichroic filter, is reflected by the first dichroic filter through the second and third prism third facets to the third prism first facet, is reflected by the third prism first facet through the third and fourth prism second facets to the second dichroic filter, and is reflected by the second dichroic filter through the fourth prism third facet; light of the second color entering the device through the second prism first facet passes through the first dichroic filter and through the second and third prism third facets to the third prism first facet, is reflected by the third prism first facet through the third and fourth prism second facets to the second dichroic filter, and is reflected by the second dichroic filter through the fourth prism third facet; and light of the third color entering the device through the fourth prism first facet passes through the second dichroic filter and through the fourth prism third facet.