Abstract
Influence of the solvent environments, pumping pulse energies and concentrations on the spectral properties of 1,2,3,8-tetrahydro-1,2,3,3,5-pentamethyl-7H-pyrrolo[3,2-g]quinolin-7-one (LD-423) have been investigated. The photophysical characteristics such as absorption, fluorescence spectra, Stokes' shift, fluorescence quantum yield, absorption, emission cross sections, extinction coefficient and amplified spontaneous emission (ASE) were measured. Here, LD-423 showed two ASE in a certain organic solution under pulsed laser excitation (Nd: YAG lambda(ex) = 355 nm). One of these peaks corresponds to the fluorescence, while the other peak is an anomalous peak which does not have a corresponding fluorescence peak. This abnormal ASE peak can be ascribed to the fact that the excited molecules are connected in the excited state and the solvent acts as a link between them.