title: Random lasing from granular surface of waveguide with blends of PS and PMMA.
abstract: Lasing from a planar waveguide with the blend of Polystyrene(PS): Poly-methylmethacrylate(PMMA) doped with tris(8-hydroxyquinolinato)aluminum(Alq(3)) and 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran(DCJTB) was investigated. Due to phase separation of the blend of PS:PMMA during the solvent evaporation process, a waveguide with granular surface was obtained, which has 2D island-like nanostructures with diameters ranging between 200 and 400 nm and heights at about 25 nm. Pumped by a YAG laser with wavelength of 355 nm, a significant random lasing was observed. Compared to the amplified spontaneous radiation (ASE) of planar waveguides with only PMMA or PS doped with Alq3:DCJTB prepared under the same conditions, the lasing threshold of the former is decreased by about 5 times, and the full width at half maximum (FWHM) is reduced to 1.7 nm from 12~15 nm. Our experiments show a promising method to achieve lower threshold for organic lasers.
authors.affiliation: Key Laboratory of Photonics Technology for information, School of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China.
authors.forename: Xuanke
authors.initials: X
authors.lastname: Zhao
authors.forename: Zhaoxin
authors.initials: Z
authors.lastname: Wu
authors.forename: Shuya
authors.initials: S
authors.lastname: Ning
authors.forename: Shixiong
authors.initials: S
authors.lastname: Liang
authors.forename: Dawei
authors.initials: D
authors.lastname: Wang
authors.forename: Xun
authors.initials: X
authors.lastname: Hou