2025/03/06 by Qing Wang, Yuhang Li, Wang, Qing +9 · 1 citation
Physics and Astronomy · Materials Science · Engineering · #Photonic Crystals and Applications #Optical Coatings and Gratings #Plasmonic and Surface Plasmon Research
paper · pdf · doi:10.48550/arxiv.2503.04366
Nanophotonic devices with moiré superlattice is currently attracting broad interest due to the unique periodicity and high efficiency control of photons. Till now, experimental investigations mainly focus on the single layer device, i.e., two or more layers of photonic crystal patterns are merged and etched in a single layer of material. By comparison, twisted photonic crystal with multilayer materials raises challenges in the nanofabrication technology, because the growth of upper layer material usually requires a smooth bottom layer without nanostructures. Hereby, we fabricate twisted heterobilayer photonic crystal in the graphite/Si3N4 heterostructure. We use dry transfer method to stack the graphite on top of bottom Si3N4 with pre-etched photonic crystal patterns. Selective dry etching recipes are used to etch two photonic crystal layers individually, which improves the quality and accuracy in alignment. The cavity photonic mode at the visible wavelength ∼ 700 nm arsing from the moiré site is clearly observed in experiment. These results reveal the experimental diagram of heterobilayer nanophotonic devices and open the way to design flexibility and control of photons in new degrees of freedom.