Viavi Solutions Inc.
Total internal reflection (TIR) prism beamsplitter

Abstract:

A dichroic prism beamsplitter may include a medium with a refractive index greater than approximately 1.0. The dichroic prism beamsplitter may include a plurality of layers sandwiched by the medium. The plurality of layers may include an equivalent structure including at least one layer with a refractive index that is less than a threshold refractive index for total internal reflection. The at least one layer may be associated with a thickness less than or equal to a threshold thickness associated with total internal reflection for a threshold wavelength. The at least one layer may cause total internal reflection for a first wavelength range that is less than or equal to the threshold wavelength and causes evanescent wave coupling for a second wavelength range that is greater than the threshold wavelength.