Low threshold gain-narrowing characteristics of fluorescent styrylbenzene derivatives as a guest molecule in an organic thin-film optical waveguide

We demonstrate that fluorescent styrylbenzene derivatives (SBDs) as a guest molecule (10 mol%) in an organic thin-film optical waveguide show excellent gain-narrowing performance by optical pumping. In particular, an extremely low threshold for gain narrowing is obtained with 4,4'-bis[4-(di-p-tolyl-amino)styryl]biphenyl (LD3). In addition, the incorporation of heterocyclic moieties into the styrylbenzene skeletons results in a higher threshold and also causes no spectral nan owing.