Microchannel-Based Refractive Index Sensors Monolithically Integrated With Silica Waveguides: Structures and Sensitivities

Refractive index sensors using self-forming microchannels embedded in borophosphosilicate glass and monolithically integrated with silica waveguides are presented. Fabricated devices presented include solid-core and liquid-core directional couplers, liquid-core modal interferometers, Mach-Zehnder interferometers, segmented waveguides, and microchannel grating devices. Sensitivities of these devices are calculated and compared with each other and to other well-known devices. Experimental characterizations show that the performance of fabricated devices agrees well with calculations.