Programmable high-order mode control method based on acoustically induced fiber grating

Abstract

We demonstrate a programmable high-order mode control method that can be implemented in high-power fiber lasers. 2 W average-power mode-locked pulses are obtained based on a mode-locked fiber laser working in dissipative soliton resonance regime. The fundamental mode (LP01) is fully or partially converted to the high-order modes (LP11a/b) via an acoustically-induced fiber grating. The mode-superposition fields are recorded using an optical 4f system, and mode components are subsequently analyzed by a mode decomposition algorithm. Our experiments suggest that the mode patterns are stable and dynamically switchable. The method is expected to possess good application value in optical tweezers, fiber communication, laser material processing and other research fields.