Patent ID: 7405384

Claim:
An illumination system comprising: a first light source operable to respond to a first feedback control circuit and generate light at a first wavelength; a second light source operable to respond to a second feedback control circuit and generate light at a second wavelength; a beam combiner operable to combine light from the first and second light sources and produce a substantially co-linear and collimated beam; a first photo-sensor operable to sense light from the first light source and the second light source to provide a signal to the first feedback control circuit, and a second photo-sensor operable to sense light from the first light source and the second light source to provide a signal to the second feedback control circuit, wherein the first photo-sensor is sensitive to light of the first wavelength and the second photo-sensor is sensitive to light of the second wavelength, wherein the beam combiner comprises a first dichroic mirror configured to receive light from the first light source and the second light source and produce the substantially co-linear and collimated beam from a first face of the first dichroic mirror, and wherein the first photo-sensor is positioned to receive light from a second face of the first dichroic mirror, and wherein the first dichroic mirror is located on a first facet of a prism structure and the first photo-sensor is positioned on a second facet of the prism structure.