3D-soliton waveguides in lithium niobate for femtosecond light pulses
Vlad, V I; Petris, A; Bosco, A; Fazio, E; Bertolotti, M; Vlad, V I; Institute of Atomic Physics, NILPRP-Romanian Center of Excellence in Photonics, Bucharest, Romania; Petris, A; Institute of Atomic Physics, NILPRP-Romanian Center of Excellence in Photonics, Bucharest, Romania; Bosco, A; Universita ‘La Sapienza’ e INFM, Dipartimento di Energetica, Via Scarpa 16, I-00161 Roma, Italy; Fazio, E; Universita ‘La Sapienza’ e INFM, Dipartimento di Energetica, Via Scarpa 16, I-00161 Roma, Italy; Bertolotti, M; Universita ‘La Sapienza’ e INFM, Dipartimento di Energetica, Via Scarpa 16, I-00161 Roma, Italy
Журнал:
Journal of Optics A: Pure and Applied Optics
Дата:
2006-07-01
Аннотация:
We show that efficient waveguides can be written by bright spatial solitons in the volume of lithium niobate photorefractive crystals by cw and pulsed laser beams. Using high-repetition-rate femtosecond laser pulses, an efficient formation of soliton waveguides (SWGs) is possible, after accumulating a large number of pulses, because the characteristic photorefractive build-up time is much longer than the pulse period and the efficient two-photon absorption may contribute to the solitonic confinement. These results open the possibility of writing reconfigurable single SWGs and SWG arrays (with any spatial orientation and large range of periods) and optimally guiding the femtosecond pulsed laser beams through them, creating a graded refractive-index profile matched to the spatial beam profile. Our experiments also show a small increase in pulse duration (small dispersion) in these waveguides.
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