A new optical resonator has unprecedented in resonance enhancement. A resonator is a device that traps waves and enhances or echoes them by reflecting them from wall to wall in a process called resonant enhancement. Today, there are complex and sophisticated resonators of various kinds throughout the world, as well as simple resonators familiar to all of us. Examples of this include the resonator box of a guitar, which enhances the sound produced by the strings, or the body of a flute, which enhances the sound created in the mouthpiece of the instrument.

A resonator is a device that traps waves and enhances or echoes them by reflecting them from wall to wall in a process called resonant enhancement. Today, there are complex and sophisticated resonators of various kinds throughout the world, as well as simple resonators familiar to all of us. Examples of this include the resonator box of a guitar, which enhances the sound produced by the strings, or the body of a flute, which enhances the sound created in the mouthpiece of the instrument.

The guitar and flute are acoustic resonators in which the sound reverberates between the walls of the resonator. In physics, there are also optical resonators, such as in laser devices. A resonator is, in fact, one of the most important devices in optics: «It’s the transistor of optics,» said Prof. Carmon.

Generally speaking, resonators need at least two mirrors to multiply reflected light (just like at the hairdressing salon). But they can also hold more than two mirrors. For example, three mirrors can be used to reflect the light in a triangular shape, four in a square, and so on. It is also possible to arrange a lot of mirrors in an almost circular shape so that the light circulates. The more mirrors in the ring, the closer the structure becomes that of a perfect circle.

But this is not the end of the story, as the ring restricts the movement of light to a single plane. The solution is a spherical structure, which allows light to rotate on all planes passing through the center of the circle, regardless of their tilt. In other words, in three-dimensional space.

In the movement from physics to engineering, the question arises of how to produce a resonator as close as possible to a sphere that is clean, smooth, and gives the maximal number of rotations for optimal resonance. It is a challenge that has engaged many research groups and has yielded, among others, a tiny glass resonator in the shape of either a sphere or ring, which is held next to a narrow optical fiber. An example of this was presented by Prof. Carmon two years ago in Nature.

Story Source: Materials provided by Technion-Israel Institute of Technology. Note: Content may be edited for style and length.