Tunable ‘metasurface’ is akin to optical swiss army
knife

MIT engineers and colleagues report important new
advances on a tunable metasurface, or flat optical device patterned
with nanoscale structures, that they compare to a Swiss army knife
while its passive predecessor can be thought of as just one tool,
like a flat-bladed screwdriver. Key to the work is a transparent
material discovered by the team that quickly and reversibly changes
its atomic structure in response to heat.