title: Optically pumped distributed feedback dye lasing with slide-coated TiO₂ inverse-opal slab as Bragg reflector.
abstract: We demonstrate an optical amplification of organic dye within a TiO2 inverse-opal (IO) distributed feedback (DFB) reflector prepared by a slide-coating method. Highly reflective TiO2 IO film was fabricated by slide coating the binary aqueous dispersions of polystyrene microspheres and charge-stabilized TiO2 nanoparticles on a glass slide and subsequently removing the polymer-opal template. TiO2 IO film was infiltrated, in turn, with the solutions of DCM, a fluorescent dye in various solvents with different indices of refraction. Optical pumping by frequency-doubled Nd:YAG laser resulted in amplified spontaneous emission in each dye solution. In accordance with the semi-empirical simulation by the FDTD method, DCM in ethanol showed the best emission/stopband matching for the TiO2 IO film used in this study. Therefore, photo excitation of a DCM/ethanol cavity showed a single-mode DFB lasing at 640 nm wavelength at moderate pump energy.
authors.forename: Sung Gu
authors.initials: SG
authors.lastname: Han
authors.forename: Jongchul
authors.initials: J
authors.lastname: Lim
authors.forename: Jinsub
authors.initials: J
authors.lastname: Shin
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Taiho
authors.initials: T
authors.lastname: Park
authors.forename: Jongseung
authors.initials: J
authors.lastname: Yoon
authors.forename: Kyoungja
authors.initials: K
authors.lastname: Woo
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Lee
authors.forename: Wonmok
authors.initials: W
authors.lastname: Lee