A numerical simulation code, based on the one-dimensional photon A numerical simulation code, based on the one-dimensional photon transport equation, was developedand analyzed to evaluate the performances of Rhodamine 6G dye laser amplifiers pumpedwith Cu-vapor lasers. The upper singlet-state absorption played an important role to determinethe efficiency. The simulation code was applied to optimize a multi-stage amplifier system with apulsed or a CW dye-laser oscillator. The analytical results gave a useful guideline to design ahigh-power pulsed dye-laser system for atomic uranium enrichment.