Optically pumped lasing from organic microcavity

Abstract

An optically pumped organic laser has been fabricated using a DCM (4-dicyanmethylene-2-methyl-6-4H-pyran)-doped Alq (tris (8-hydroxyquinoline) aluminum) film as the gain medium sandwiched between a high-reflectance distributed Bragg reflector and a silver reflector. The stimulated emission properties were investigated by short-pulse laser pumping. The intensity ratio of the resonant peak at 604 nm to the DBR (distributed Bragg reflector)-modulated free space emission band changed greatly with increasing pump energy density. The dependence on the pump energy density of the output properties including the cavity mode output, the total output, and the ratio of the cavity output versus total output, indicates a clear threshold energy density of 400 ± 20 µJ/cm2. The effective gain coefficient at the threshold was about 250 ± 14 cm–1. PACS No.: 42.55.Sa