Tunable organic thin-film laser pumped by an inorganic violet diode laser

We demonstrate an organic thin-film distributed feedback (DFB) laser pumped by an inorganic violet laser diode (λ=406nm). The active organic medium consists of a highly efficient, modified poly(9,9-dioctylfluorene) derivative containing 12% of statistical intrachain 6,6′-(2,2′-octyloxy-1,1′-binaphthalene) binaphthyl spacer groups. The polymer is doped with 4wt% of the stilbene dye 1,4-bis(2-(4-(N,N-di(p-tolyl)amino)phenyl)vinylbenzene). This guest-host system features minimum lasing threshold energy densities below 1μJ∕cm2 for second order DFB resonator geometries and significant absorption (7.3×104cm−1) at the wavelength of the pumping diode laser. The entire setup states an extremely compact and cost effective, laser source tunable between 496 and 516nm.