High-efficiency Nd-doped fibre lasers using direct-coated dielectric mirrors

The letter presents an Nd-doped silica single-mode fibre laser with dielectric mirrors coated directly on to the fibre endfaces. The LD-pumped fibre laser had a CW output power of more than 4mW, a threshold power of 1.51 mW and a slope efficiency of 55%. The theoretically predicted values and experimental values of the laser characteristics are very similar owing to a negligibly small excess cavity loss.