Fig. 2.

Active metasurfaces. a Schematic illustration of reconfigurable photonic devices in a phase-change film with optical components, such as lenses and resonant metamaterials, written in a chalcogenide glass phase-change film using fs pulses. The written pattern can also be erased using the same laser with different illumination conditions. The results are observed through the “read” channel¹⁸. b Example of a 2D material, layered hBN, positioned on a plasmonic metal array for achieving enhanced single-photon emission. The inset is the second-order correlation function that confirms that a single quantum emitter is probed²⁰. c Schematic illustration of a DM integrated into a liquid crystal cell. By heating the liquid crystal, it changes its state from nematic to isotropic, resulting in a spectral shift of the metasurface resonances and the tuning of the emission enhancement²¹