We investigate an improvement in the pump slope efficiency for an erbium-doped fiber-ring laser. The method is based on the residual pump power reused by means of a fiber mirror. Under the conditions of a 4-m erbium-doped fiber (EDF), 10 mW of pump power, and a 99% reflectivity of a fiber-Bragg grating, the pump slope efficiency may reach 19.70% compared to 15.37% for a conventional fiber-ring laser. The maximum lasing power is increased from 14.6 to 18.7 mW corresponding to a 1.07-dB lasing power enhancement. The side-mode suppression ratio is as high as 67.6 dB with a line width of less than 0.05 nm.