Effects of excited-state absorption and amplified spontaneous emission in a high-average-power dye laser amplifier pumped by copper vapor lasers

The amplification characteristics of a dye laser amplifier with a gain length of 20 mm pumped by a high-average-power copper vapor laser system are studied. The characteristics of the dye laser amplifier are analyzed by rate equations in which excited-state absorption (ESA) and amplified spontaneous emission (ASE) are taken into consideration. In the experiment, the energy extraction efficiency of about 48% is obtained for the amplifier. The calculation shows that the main factors of the energy loss in the amplifier are ASE and ESA and the former is dominant at the low-input-power region and the latter at the high-input-power region. The output power decreases around 10% by the ESA near the peak wavelength of rhodamine 6G dye. (C) 1996 Society of Photo-Optical Instrumentation Engineers.