High Power Random Fiber Laser With Short Cavity Length: Theoretical and Experimental Investigations

In this paper, we make a comprehensive study on a highly efficient half-open cavity design for high power random fiber laser (RFL). With the theoretical analysis, we optimize the cavity´s fiber length for getting higher output power within the scheme, i.e., shorter fiber length is preferred for efficiently harvesting the first order random lasing at the open end of the cavity. As the verification of the theory, we experimentally demonstrate a high output power (7 W), highly efficient (70% optical conversion efficiency) RFL working at 1140 nm, using 10 W 1090 nm laser as the pump source and only 1 km standard single-mode fiber as the distributed cavity.