Mode-selective few-mode Brillouin fiber laser and its application

Fiber lasers of high-order spatial modes are advantageous in a number of applications. We experimentally demonstrate a transverse mode-selective few-mode Brillouin fiber laser using a pair of mode-selective photonic lanterns as spatial mode filters. The three LP lasing modes were generated based on both intra- and inter-modal stimulated Brillouin scattering. Their slope efficiencies, optical spectra, mode profiles, and linewidths were characterized for both cases. Based on the ring-cavity configuration, distributed temperature and strain sensing with 1-m spatial resolution is also demonstrated. The Brillouin dynamic grating was generated in the LP01 mode and high-order modes were used as probes. The feasibility of simultaneous temperature and strain sensing has also been investigated.