Substrates, systems and methods for analyzing materials that include waveguide arrays disposed upon or within the substrate such that evanescent fields emanating from the waveguides illuminate materials disposed upon or proximal to the surface of the substrate, permitting analysis of such materials. The substrates, systems and methods are used in a variety of analytical operations, including, inter alia, nucleic acid analysis, including hybridization and sequencing analyses, cellular analyses and other molecular analyses.