Low-threshold deep-blue organic thin-film distributed feedback laser

A low-threshold distributed feedback organic solid-state laser based on terfluorene and pumped by a pulsed Nd:YAG laser is reported. The second-order DFB grating with a period of 280 nm or 300 nm is realized by electron-beam lithography of the e-beam resist. Observations show lasing action occurring at 423 nm and 448 nm above the threshold with emission wavelength in the deep blue region.