Ultrafast and Broadband Tuning of Resonant Optical Nanostructures Using Phase‐Change Materials

A combination of Au nanohole arrays with a phase-change material (PCM) is presented, which exhibits large optical contrast upon transitions from its amorphous to crystalline stable phases. The presence of the PCM allows to shift the position of the resonance produced by the nanohole array up to 385 nm. Moreover, it is also shown how this resonance can be tuned in the ultrafast regime without the need for a structural transition in the PCM.