113 research outputs found

    Frequency-Doubling of Femtosecond Pulses in “Thick” Nonlinear Crystals With Different Temporal and Spatial Walk-Off Parameters

    Get PDF
    We present a comparative study on frequency-doubling characteristics of femtosecond laser pulses in thick nonlinear crystals with different temporal and spatial walk-off parameters. Using single-pass second harmonic generation (SHG) of 260 fs pulses at 1064 nm from a high-average-power femtosecond Yb-fiber laser in 5-mm-long crystals of β-BaB2O4 (BBO) and BiB3O6 (BIBO), we find that for comparable values of temporal and spatial walk-off parameters in each crystal, the optimum focusing condition for SHG is more strongly influenced by spatial walk-off than temporal walk-off. It is also observed that under such conditions, the Boyd and Kleinman theory commonly used to define the optimum focusing condition for frequency-doubling of cw and long-pulse lasers is also valid for SHG of ultrafast lasers. We also investigate the effect of focusing on the spectral, temporal, and spatial characteristics of the second harmonic (SH) radiation, as well as angular acceptance bandwidth for the SHG process, under different temporal and spatial walk-off conditions in the two crystalsPeer ReviewedPostprint (author's final draft

    Influência da espessura da aleta na convecção forçada em um duplo tubo aletado internamente - solução pelo método de golub

    Get PDF
    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia Mecânica

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

    Get PDF
    corecore