Durable and programmable ultrafast nanophotonic matrix of spectral pixels

Abstract

Locally addressable nanophotonic devices are essential for modern applications such as light detection, optical imaging, beam steering and displays. Despite recent advances, a versatile solution with a high-speed tuning rate, long-life durability and programmability across multiple pixels remains elusive. Here we introduce a programmable nanophotonic matrix consisting of vanadium dioxide (VO2) cavities on pixelated microheaters that meets all these requirements. The indirect Joule heating of these VO2 cavities can result in pronounced spectral modulation with colour changes and ensures exceptional endurance even after a million switching cycles. Precise control over the thermal dissipation power through a SiO2 layer of an optimized thickness on Si facilitates an ultrafast modulation rate exceeding 70 kHz. We demonstrated a video-rate nanophotonic colour display by electrically addressing a matrix of 12 × 12 pixels. Furthermore, inspired by the unique pixel-level programmability with multiple intermediate states of the spectral pixels, a spatiotemporal modulation concept is introduced for spectrum detection. Electrically addressable VO2 elements show large resonance shifts during phase transitions, producing a brilliant colour change at a modulation rate of 70 kHz.