A Ham radio operator will tell you all about the standing wave ratio (SWR) of his antenna, and he may even have a meter in the shack to measure it. He’ll know that a 1.1 to 1 SWR is a good ...

This creates a series of standing-wave optical modes, or resonances, similar to those that can exist on a vibrating guitar string. Microresonators can provide the optical feedback required in ...