New laser compounds emitting in green region under flashlamp excitation

We report the development of a novel series of laser compounds and describe the performance of these materials. The new laser dyes are the derivatives of 7H-benzo[4,5]imidazo[1,2-c]chromeno[3,2-e]pyrimidine. They have been synthesized by condensation of 2-imino-3-(benzimidazolyl-2)-benzopyrans with aromatic aldehydes. The new compounds fluoresce in the green spectral region with high quantum yield. Efficient laser action of their methanol solutions has been obtained under flashlamp excitation with pulse width of 2.0 /spl mu/s (FWHM). The output laser radiation of these solutions in a non-selective cavity was in the 540-570 nm region.. The influence of molecular structure of investigated dyes on their fluorescence and laser characteristics are discussed.