Search results for "ultra-short pulse"
showing 3 items of 3 documents
Similaritons in optical fiber Raman amplifiers
2005
This thesis presents the generation of optical similaritons in a normally dispersive Raman amplifier at telecom wavelengths. The pulses experimentally characterized by FROG technique exhibit a parabolic intensity profile with a linear chirp, in good agreement with results of numerical simulations.Several theoretical features of the similaritons have been experimentally studied. The dynamics of two similaritons with same or different central wavelengths is also investigated: similaritons are robust against collisions, whereas the interaction of similaritons leads to the generation of high-repetition rate dark soliton train.The similariton properties have been finally applied into three field…
Coherent Amplification of the Short Optical Pulse in a Non-linear Birefringent Medium
2006
International audience; The propagation of the solitary waves in the resonant birefringent amplifier with linear losses is considered. The birefringent optical linear medium contains two-level atoms with the upper state degenerated over projection of angular moment. It is assumed that population of resonance levels of atoms is inverted. The steady state pulse of polarized radiation that is vectorial generalization of the known pi-pulse was analytically found. Numerical simulations demonstrate the formation dynamics solitary waves originated in birefringent amplifier.
Alignment of linear molecules by short duration laser pulses
2005
Alignment of linear molecules is efficiently induced by strong linearly polarized laser pulses. In the case of short pulses with respect to molecular rotation, periodic alignment appears in field-free conditions after the extinction of the field. This manuscript presents three techniques where the value of allows to quantify alignment without molecular dissociation nor additional alignment. They use a weak time-delayed probe pulse which experiences the optical properties of an aligned sample and shows modification of its characteristics. The first of them measures a depolarization due to the birefringence of the sample. The second one is based on the defocusing produced by the spatial distr…