Optical fibers made of silica glass can guide light along a long distance without significant loss and are widely used for optical communications today. While the silica glass has very high stability in optical and mechanical properties, it is very difficult to dynamically control the parameters of light in the fiber without taking the light out of the fiber. We noticed that the silica glass fiber is also an excellent guide for acoustic waves and demonstrated that the light in fiber can be efficiently modulated using acousto-optic interaction while keeping the light in the fiber. This is equivalent to Bragg cell realized in the fiber. The obtained results have many potential applications, and one form of the device (acousto-optic tunable filter) was commercialized for telecommunications applications funded by Silicon Valley venture capitals.
In this talk, I will discuss the acousto-optic effect in optical fibers and will also describe the commercialization process of the all-fiber tunable filters.