Figure 2

(a) Illustration of the power transfer between a silicon and GST/Si waveguide. Due to the optical mismatch between both waveguides, the incident power (\(P_{in}\)) is radiated outside the waveguide (\(P_{rad}\)), reflected (\(P_{r}\)), and transmitted (\(P_{t}\)). (b) Illustration of the technique used to obtain the coupling efficiency between the optical modes of the GST/Si waveguide and the fundamental TE mode of the silicon waveguide by exploiting the reciprocity property of the coupling process.