It's a spooky feature of Grand Central Station that if you whisper something against the wall, your voice can resonate around the perimeter of the building and sneak up on you from behind. The same 'whispering gallery' principle is crucial to next-gen optical computing: light signals have to be sent on extremely circuitous journeys through 'microresonators', which temporarily bottle up the beams and thereby serve as memory.
So far, microresonators have generally been made from silicon wafers etched with the a long series of loops. However, even the most precise etching leaves i
