Methods and an optical interrogation system for monitoring structural health of a structure are provided. The method includes generating an optical signal using an optical signal generator, and directing the optical signal towards at least one optical sensor located remotely from the optical signal generator. The optical sensor includes a photonic crystal wafer optically interacting with the optical signal and an environmental condition. The method also includes capturing, by an optical signal receiving apparatus, a reflected optical signal reflected from the at least one optical sensor, and analyzing the reflected optical signal to determine a change in the environmental condition.