Gain studies of Coumarin 503 dye-doped polymer laser

Solid-state dye doped polymer is an attractive alternative to the conventio nal liquid dye solution. In this paper, the laser characteristics of Coumar in 503 (C503) doped polymethyl methacrylate (PMMA) rods modified with ethyl alcohol (EtOH) are studied under nitrogen laser excitation in a transverse pumping configuration and the variation of gain of the dye in solid medium for different pumping powers is studied. The gain of Coumarin 503 in solid medium is compared with the gain of Coumarin 503 in liquid medium and it i s found that the gain of the dyes in the solid environment is less than tha t in the liquid environment. The photobleaching of dye in polymer medium un der nitrogen laser excitation is also studied by keeping the rod in a fixed position and by rotating the rod about its cylindrical axis. It is found t hat the photobleaching rate is faster when the rod is in a fixed position. (C) 2000 Elsevier Science Ltd. All rights reserved.