RATE-EQUATION STUDIES OF ERBIUM-DOPED FIBER LASERS WITH COMMON PUMP AND LASER ENERGY-BANDS

Erbium-doped-fiber lasers with the laser transition and pump absorption sharing common energy bands are studied theoretically by using rate equations based on the interaction between a two-level atom and a two-wavelength field. Explicit and analytical expressions are established for the threshold pump power, output power, and slope efficiency of the laser oscillator under steady-state conditions. Constraints on the choice of the fiber length, the pump wavelength, and the laser wavelength are quantified, and the effects of the residual reflectivity at the pump wavelength on the oscillator characteristics are investigated.