Demonstration of diffraction enhancement via Bloch surface waves in a-SiN:H multilayers

By exploiting the excitation of a Bloch surface wave at a wavelength λ=670 nm, we observe a diffraction enhancement of more than 45 times from a rabbit IgG protein grating printed on a-SiN:H multilayers. Our results demonstrate that the use of surface states in dielectric multilayers is very promising for the realization of the next generation of diffraction-based biosensors.