New metamaterials can change properties with a flick of a light-switch

This is a cross-sectional scanning electron microscopy images of a 750 nm period grating fabricated by focused ion beam milling in a 300 nm thick amorphous germanium antimony telluride film on silica. Image: Karvounis/Gholipour/MacDonald/Zheludev, Optoelectronics Research, University of Southampton