Abstract :
Rare-earth doped, laser-diode-pumped, single-mode, double-clad fiber lasers are studied in detail, experimentally and theoretically, with particular attention to properties of scaling to higher output powers. Gain saturation, spontaneous emission, fiber propagation loss, and the optimum output coupler are considered for oscillator design and laser performance. Thermal properties are investigated, including the thermal fracture limit, the decrease of quantum efficiency with increasing pump power through the temperature dependence of multiphonon decay and ion-ion energy transfer, and thermal lensing. Self-focusing and Raman effects are briefly considered. It is shown that output powers in the tens of watts range are readily feasible with available double-clad fiber lasers
Keywords :
claddings; fibre lasers; laser modes; multiphoton processes; optical losses; optical pumping; optical saturation; optical self-focusing; rare earth metals; Raman effects; double-clad; fiber propagation loss; high power rare-earth-doped fibre lasers; higher output powers; ion-ion energy transfer; laser gain saturation; laser performance; laser-diode-pumped; multiphonon decay; optimum output coupler; oscillator design; output powers; pump power; quantum efficiency; scaling; self-focusing; single-mode; spontaneous emission; temperature dependence; thermal fracture limit; thermal lensing; thermal properties; Fiber lasers; Laser theory; Optical fiber couplers; Performance gain; Power generation; Power lasers; Propagation losses; Pump lasers; Spontaneous emission; Thermal lensing;
