Final rept. 15 Jan 2013-14 Jan 2014
STATE UNIV OF NEW YORK AT BUFFALO INST FOR LASERS PHOTONICS AND BIOPHOTONICS
Pagination or Media Count:
In the first year we focused on Multiphoton processes and their amplification in a nanocomposite medium to achieve upconversion lasing. This work was accomplished by collaboration with Professor Anderson Gomes s group at Recife, Brazil. A significant research was accomplished and the resulting work was submitted to Optics Express, a high impact journal, for publication. We have received the reviewers s comment. The two reviews who were asked to evaluate, have both given a positive review and asked for some revision. This work reports the operation and characterization of an upconversion random laser emitting at 560nm, when directly pumped by three photon excitation at the near IR wavelength of 1350nm in a colloidal dye solution in the weakly scattering regime. Using a special dye with a high three-photon cross-section and TiO2 nanoparticles 250 nm diameter, optimized upconverted emission was obtained for particle densities of 2 x 109cm3. A strong dependence on the nanoparticle concentration and the pumping area was verified. The presence of spikes with linewidths 0.4 nm in the emitted spectrum is the signature of coherent emission from this three-photon pumped random laser.