We present the design. fabrication. and characterization of submicronic grating couplers integrated on Si3N4 rib waveguide Mach-Zehnder interferometers (MZIs) for biosensing applications working in the visible spectral range for both TE and TM polarizations. Depending on the waveguide structure. https://fitnessgravesyardes.shop/product-category/switch-overlay/