Two-photon pumped fluorescence and lasing of phenalenon derivatives

Two-photon pumped fluorescence and lasing of phenalenon derivatives is presented in this paper. Results of investigations in spontaneous and stimulated emissions of 4 organic molecules of phenalenon derivatives (phenalemines) in solutions and polymer matrices of polymethylmethacrylate (PMMA) under two-photon excitation with Nd/sup 3+/ :YAG-laser radiation (1064 nm, 7 ns, and 40 mJ) are given. The efficiency of two- photon fluorescence (TPF) of these compounds is estimated compared to rhodamine 6G. The spectra of conventional fluorescence and TPF and also the TPF efficiency in ethanol solutions and PMMA are compared. For one of the examined compounds (phenalemine 512) with a maximum TPF efficiency of (4-5)/spl middot/10/sup -9/ cm/sup 4//spl middot/s/photon/spl middot/mol, two-photon lasing in ethanol solution and PMMA has been excited in spectral ranges centered at 629 and 615 nm, respectively. The prospects for applications of the examined materials are also discussed.