Effect of excited-state absorption at signal wavelength in pulsed-dye-laser amplifiers

The effect of excited-state absorption (ESA) at the laser wavelength in transversely pumped pulsed-dye-laser amplifiers is theoretically examined. Assuming steady-state conditions, it is shown that ESA along with ground-state absorption introduces a nonlinear loss term in the amplifier equation. An improved expression for the saturated gain is obtained, and it is shown that the amplifier extraction efficiency does not saturate with increase in dye-laser input power, but shows a maximum and then decreases. These theoretical results are compared with experimental measurements on copper-vapor laser-pumped dye-laser amplifiers.<
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