Luminescence and amplified spontaneous emission (ASE) phenomenon of 3-(1,1-dicyanoethenyl)-1-phenyl-4,5-dihydro-1H-pyrazole (DCNP) dissolved in a polymethyl methacrylate (PMMA) matrix have been studied. We analyzed luminescence from thin films of DCNP-PMMA excited by the neodymium doped yttrium aluminum garnet (Nd:YAG) nanosecond pulsed laser doubled and tripled in frequency. We report on ASE in function of different excitation pulse energy densities (ASE threshold was estimated to be 10 and 13 mJ/cm(2) for pumping beams wavelengths of 532 and 355 nm, respectively). We observed the photo-degradation process of a dye and performed exponential gain coefficient measurements (up to 10 cm(-1)) in the system. (C) 2011 Elsevier B.V. All rights reserved.