Active tunable filters based on GeSbTe phase-change materials and surface plasmon resonance (Conference Presentation)

Tunable mid-wave infrared (MWIR) filters are highly desirable in a wide variety of imaging and sensing applications. Here, we demonstrate a solid-state, actively tunable, narrowband MWIR transmission filter based on a plasmonic nanohole array (PNA) design integrated with the phase change material GeSbTe (GST). Through finite-difference time domain simulations and experimental results, we show narrowband (~100nm), high-efficiency (~90%) transmission filtering, tunable across the entire MWIR spectrum (1~10µm). The active tunability of the GST/PNA filter has been experimentally demonstrated by single-shot pulsed laser irradiation-induced phase transformation and the device shows consistent behavior across a number of phase change cycles.