Bistable active spectral tuning of one-dimensional nanophotonic crystal by phase change

Active spectral tuning of nanophotonic devices offers many fascinating prospects for the realization of novel optical function. Here, switchable spectral response is enabled by the architecture of one-dimensional (1D) photonic crystal (PC) integrated with phase change material of the germanium antimony telluride (GST). Active and precise tuning of the bistable passband and central resonant frequency is demonstrated in the 1D PC composed of alternate SiN and GST nanofilms. An analytical model is derived to specify the tunable spectral features, including the band gap and resonant frequencies. Both the measured and calculated results show distinct red shifts of passband and the resonant minima (or maxima), well confirming theoretical predictions. This work demonstrates a route to construct active photonic devices with the electrically or thermally tunable spectra via 1D PC and potentially extends diverse applications based on the PC platform.