Long-term polarization stabilization of a polarization maintaining fiber via dynamic temperature control

We achieved long-term polarization stabilization of the output beam obtained from polarization-maintaining (PM) fiber by feeding heat back to the fiber. Optical polarization stability is crucial in various fundamental and engineering fields, particulary in a miniaturized field-deployable system composed of optical components, such as cold-atom-based quantum sensors. We constructed a feedback loop to stabilize the polarization of the output beam of a PM fiber in thermal contact with a Peltier element. Notably, a long-term polarization stability against thermal fluctuations was achieved, and the characteristics of the thermal polarization stabilizer were analyzed based on the power spectral density, Allan deviation, and Bode plots. The results indicate that this system can effectively serve as a long-term intensity stabilizer and is ideal for use in laboratories in which PM fibers are widely used, but exact temperature regulation is not feasible.