Optical ring resonator-based microfluidic sensor

A structure comprising:

• a substrate having a first surface and a second surface opposite the first surface, wherein the substrate is a semiconductor substrate;
• an insulator layer immediately adjacent to the second surface of the substrate;
• and
• multiple optical ring resonators, wherein each optical ring resonator comprises:
• cladding material on the insulator layer;
• a first waveguide core;
• and
• at least one second waveguide core, wherein the at least one second waveguide core has a closed curve shape and is positioned laterally adjacent to the first waveguide core, wherein the first waveguide core and the at least one second waveguide core have bottom surfaces adjacent to the insulator layer, top surfaces opposite the bottom surfaces, and side surfaces, and wherein the top surfaces and the side surfaces are covered by the cladding material;
• and
• a reservoir comprising multiple channels extending through the substrate from the first surface to the second surface and further through the insulator layer to the cladding material,
• wherein each channel is aligned with a corresponding optical ring resonator, and
• wherein the bottom surfaces of the first waveguide core and the at least one second waveguide core of the corresponding optical ring resonator are at least partially exposed within the channel.

A structure comprising:

• a substrate having a first surface and a second surface opposite the first surface, wherein the substrate is a semiconductor substrate;
• an additional substrate immediately adjacent to the first surface;
• an insulator layer immediately adjacent to the second surface;
• an optical ring resonator comprising:
• cladding material on the insulator layer;
• a first waveguide core;
• and
• at least one second waveguide core, wherein the at least one second waveguide core has a closed curve shape and is positioned laterally adjacent to the first waveguide core, wherein the first waveguide core and the at least second waveguide core have bottom surfaces adjacent to the insulator layer, top surfaces opposite the bottom surfaces, and side surfaces, where the top surfaces and the side surfaces are covered by the cladding material;
• and
• a reservoir extending through the additional substrate, through the substrate from the first surface to the second surface, and further through the insulator layer to the cladding material, wherein bottom surfaces of the first waveguide core and the at least one second waveguide core are exposed within the reservoir.