Patent ID: 7095920

Claim:
An optical via comprising: (a) a first waveguide in a first planar layer, said first waveguide having a first refractive index value and an input end, and supporting an optical mode with a first effective index value, (b) a second waveguide in a second planar layer, said second waveguide having a second refractive index value and an output end, and supporting a second optical mode with a second effective index value, (c) said first mode of first waveguide and said second mode of second waveguide evanescently interacting over an interaction length, and (d) means for adjusting the magnitude of said mode-to-mode evanescent interaction, adjusting the detuning between said effective indexes of said first and second modes, and adjusting said interaction length, in such a way as to effect broadband and substantially complete optical power transfer from said input end of the first waveguide to said output of the second waveguide; wherein the optical via introduces less than 0.1 dB of excess loss in a band of wavelengths between 1510 nm and 1620 nm.