Optical gain measurements in polymethyl methacrylate plastic doped with perylimide dyes

The effective optical gain is measured in a polymethyl methacrylate plastic slab doped with perylimide dyes and found to be positive. The experimental set-up is based on a single exciting laser beam, and the detection of a one pass amplified light emitted along the length of an optically excited sample. The photoluminescence output intensity varies exponentially with the length of the excited region. Under moderate pumping intensities, net laser gains of 53 and 36 cm−1 are measured for yellow KF 241 and red BASF 339, respectively.