Quast-aromatic heterocyclics as laser dyes

Superior laser dyes were recently discovered in the quasi-aromatic families of syn-dioxabimanes and pyrromethene-Bf2 complexes. The representative new dye α-bis-(carboethoxy) methylene-syn-(methylene,methyl) bimane lased at 507 nm with 50% grater efficiency than was obtained with Coumarin 30. A similar determination showed 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene to lase at 546 nm with about 300% greater efficiency than was obtained from Coumarin 545. These quasi-aromatic systems are readily available and offer desirable properties of stability (photo, thermal, and chemical), solubility, and diminished triplet-triplet absorption in the lasing spectral region. Selected spectroscopic and lasing properties of these new laser dyes are presented