A silicon photonic platform comprising: a substrate supporting a buried oxide layer; an active silicon layer on the buried oxide layer; and a first waveguide layer separated from the active silicon layer by a first spacer, the first waveguide layer and the active silicon layer constituting a first light-transferring interlayer transition; wherein the silicon photonic platform further comprises a second waveguide layer separated from the first waveguide layer by a second spacer, the first waveguide layer and the second waveguide layer (76, 78) constituting a second light-transferring interlayer transition wherein the active silicon layer comprises first, second and third silicon waveguides (74A, 74B, 75), wherein the first and second silicon waveguides (74A, 74B) are disposed on opposite sides of the third silicon waveguide; the first light-transferring interlayer transition comprises first and second waveguide sections (76A, 76B) in the first waveguide layer, wherein the first waveguide section is optically coupled to the first silicon waveguide through the first spacer, and wherein the second waveguide section is optically coupled to the second silicon waveguide through the first spacer; the second light-transferring interlayer transition comprises a third waveguide section in the second waveguide layer, wherein the third waveguide section is optically coupled at its opposed ends to the first and second waveguide sections (76A, 76B) through the second spacer, so as to optically couple the first and second silicon waveguides (74A, 74B) over and across the third silicon waveguide, characterized in that the first and second waveguide layers (76, 78) are made of a dielectric material having a refractive index within +/-20% of the refractive index of silicon nitride. a substrate supporting a buried oxide layer; an active silicon layer on the buried oxide layer; and a first waveguide layer separated from the active silicon layer by a first spacer, the first waveguide layer and the active silicon layer constituting a first light-transferring interlayer transition; wherein the silicon photonic platform further comprises a second waveguide layer separated from the first waveguide layer by a second spacer, the first waveguide layer and the second waveguide layer (76, 78) constituting a second light-transferring interlayer transition wherein the active silicon layer comprises first, second and third silicon waveguides (74A, 74B, 75), wherein the first and second silicon waveguides (74A, 74B) are disposed on opposite sides of the third silicon waveguide; the first light-transferring interlayer transition comprises first and second waveguide sections (76A, 76B) in the first waveguide layer, wherein the first waveguide section is optically coupled to the first silicon waveguide through the first spacer, and wherein the second waveguide section is optically coupled to the second silicon waveguide through the first spacer; the second light-transferring interlayer transition comprises a third waveguide section in the second waveguide layer, wherein the third waveguide section is optically coupled at its opposed ends to the first and second waveguide sections (76A, 76B) through the second spacer, so as to optically couple the first and second silicon waveguides (74A, 74B) over and across the third silicon waveguide, characterized in that the first and second waveguide layers (76, 78) are made of a dielectric material having a refractive index within +/-20% of the refractive index of silicon nitride.