Fiber Bragg grating

A Fiber Bragg Grating is like a special kind of prism. It's made of glass and when light passes through it, it splits apart into all the colors of the rainbow like a rainbow in the sky. But instead of a rainbow, the Fiber Bragg Grating splits the light into very specific colors that are determined by the shape of the grating. This is useful because it can help us measure things like temperature and pressure or detect signals from other devices.