There are used many different sources of radiation in present optic systems. The paper presents the beam splitters of radiation at a three different diode lasers used to one optical path. There were analyzed wavelengths: 670, 830, and 904 nm at 45 degrees angle of incidence.
"Beam splitters in diode laser systems", Proc. SPIE 3186, Laser Technology V: Physics and Research and Development Trends, (14 August 1997); doi: 10.1117/12.280491; https://doi.org/10.1117/12.280491