High power and high efficiency yellow laser in Dy3+-doped single-mode double-clad structured waterproof fluoro-aluminate glass fiber.

We demonstrated a single-mode yellow fiber laser using a Dy3+-doped single-mode double-clad structured weatherproof fluoro-aluminate glass fiber (Dy3+:SM-DC-WPFGF) and a 450-nm GaN laser diode (LD) as the excitation light. The power of 445 mW and the slope efficiency of 51.2% were achieved for the single-mode yellow fiber laser. The power level was approximately 20 times higher than our previous result due to improved efficiency of the focusing optics and increased Dy3+ doping concentration (10,000 ppm) in the fiber core. This yellow fiber laser shows particular promise for use in the medical field, e.g., for the treatment of melasma and telangiectasia. • We demonstrated a single-mode yellow laser with the power of 445 mW and a slope efficiency of 51.2% in Dy3+:SM-DC-WPFGF. • To our knowledge, this is the first time a highly efficient half-watt single-mode yellow fiber laser has been achieved. • This achievements thank to an improved focusing optics and an increased Dy3+ concentration (10,000 ppm) in the fiber core. • This yellow fiber laser shows particular promise for use in the medical field, e.g., for the treatment of melasma. [ABSTRACT FROM AUTHOR]