Brillouin dynamic gratings in few-mode PM fibers for distributed sensing

We provide a brief review on the measurement and applications of Brillouin scattering and Brillouin dynamic gratings in few-mode polarization-maintaining optical fibers. The experimental results based on an elliptical-core two-mode fiber and a PANDA-type few-mode fiber are compared, and the result of the feasibility study on their possible application to distributed fiber sensors is also presented.