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Autori: I. Procino, R. Velotta, C. Altucci, S. Amoruso, R. Bruzzese, X. Wang, V. Tosa, G. Sansone, C. Vozzi, M. Nisoli
Editorial: Optics Letters 32, 1866 (2007), 32, p.1866, 2007.
We demonstrate the use of a very simple, compact and versatile method, based on the hollow fiber compression technique, to shorten the temporal length of visible laser pulses of 100÷400 fs to pulse durations shorter than 50 fs. In particular, 200-fs, frequency-doubled, Nd:glass laser pulses (527 nm) were spectrally broadened to final bandwidths as large as 20 nm by nonlinear propagation through an argon-filled hollow fiber. A compact, dispersive, prism-pair compressor was then used to produce as short as 40 fs, 150 J pulses, with a well shaped, truncated-Bessel spatial profile. We also numerically integrated the nonlinear Schrödinger equation, describing the ultrashort pulse propagation in the gas-filled hollow fiber, to interpret and support our experimental results, thus obtaining a very satisfactory agreement in the selected experimental conditions.
Cuvinte cheie: pulse propagation, fiber, pulse shortening, numerical modeling