We proposed an integrated-optical biosensor configuration that operates at a wavelength of 0.63 μm based on the evanescent-wave and lateral two-mode power coupling of Si3N4 rib-optical waveguides formed on a Si/SiO2/Si3N4/SiO2 multilayer thin films. The coupling between the two propagating modes in the sensing region produces a periodically repeated optical power exchange along the propagation. […]