3. All-optical polarization control systems for fiber optics

In parallel with the commercial systems described above, a number of research laboratories have been developing devices for controlling the polarization of light in an all-optical way. These innovative polarization stabilization systems stem from the exciting field of research into the "control of light by light", and are usually based on the non-linear properties of the propagation medium used. The main advantage of these devices is that they do not require an electronic feedback system to stabilize the output polarization, paving the way for extremely short response times.

In the following paragraphs, we'll give a brief overview of nonlinear optics, then describe the principle behind existing systems developed in the laboratory, before describing the process at work in our device.