Spinning the light: The world's smallest optical gyroscope

Gyroscopes are devices that help vehicles, drones, and wearable and handheld electronic devices know their orientation in three-dimensional space. They are commonplace in just about every bit of technology we rely on every day. Originally, gyroscopes were sets of nested wheels, each spinning on a different axis. But open up a cell phone today, and you will find a microelectromechanical sensor (MEMS), the modern-day equivalent, which measures changes in the forces acting on two identical masses t...