Search results for "Nonlinear optics"
showing 10 items of 482 documents
Grating compensated dispersion-managed systems incorporating nonlinear optical loop mirrors
2006
In this work, we investigate the use of nonlinear optical loop mirrors (NOLMs) in DM fiber systems compensated by CFGs with GDR by launching a 128-bit Gaussian-shaped pseudo-random bit sequence having pulse width of 5 ps for simulating a 40 Gb/s system. The dispersion map contains a fiber segment of length 10.3 km and a CFG with dispersion of -15.6 ps/nm. We consider a lossless grating and the GDR is modeled by a sinusoidal function for simplicity. We have shown that the use of NOLMs can substantially improve the transmission performance in a grating-compensated DM fiber system even with presence of amplifier noise and random variations of GDR, parameters in CFGs along the propagation dista…
Observation of collapse arrest in pure kerr media sustained by a parametric interaction
2013
We demonstrate a parametric interaction based on four wave mixing that can arrest the collapse and stabilize solitary propagation in a pure Kerr material by controlling the wavelength of the interacting beams.
Laser-induced field-free alignment of the OCS molecule
2007
We investigate the dynamical alignment of jet-cooled OCS molecules induced by a short laser pulse. The alignment is measured through the orientational contribution of the optical Kerr effect using a second weak laser pulse as a probe. Maximum alignment is observed at conditions close to saturation of ionization. The results are analysed with a quantum mechanical model solving for the rotational dynamics.
Incoherent modulation instability in instantaneous nonlinear Kerr media
2005
We demonstrate theoretically and experimentally in an optical fiber system that partially temporally incoherent light exhibits modulational instability during its propagation in an instantaneous response nonlinear medium. We show that the modulation frequency and gain are substantially increased with respect to the corresponding values of coherent modulational instability.
A paradigm of fullerene
2009
We study the dynamics of an electron constrained over the surface of a rigid sphere, with geometrical parameters similar to those of the C60 fullerene, embedded in a low intensity linearly polarized laser field. The model is shown to emit odd harmonics of the laser even at very low field intensity. For more intense laser fields, the spectrum presents odd harmonics and hyper-Raman lines shaped in a broad plateau. The spectrum of the model is compared to that theoretically obtained by other authors for more realistic models of C60. It is concluded that the model can be used as a paradigm for mesoscopic molecules in the fullerene family, particularly in practical applications where it is conve…
Soliplasmon excitations at metal/dielectric/Kerr structures
2009
We present novel optical phenomena based on the existence of a new type of quasi-particle excitation in metal/dielectric/Kerr structures. We discuss the possibility of excitation of surface plasmon polaritons via spatial solitons in these systems.
Experimental observation of incoherent modulation instability in standard optical fibers
2005
In this work, we demonstrate theoretically and experimentally that a partially temporally incoherent light can exhibit modulational instability when propagating in an optical fiber with instantaneous nonlinear Kerr response.
Role of Polarization Mode Dispersion on Modulational Instability in Optical Fibers
2001
We introduce the theory of modulational instability (MI) of electromagnetic waves in fibers with random polarization mode dispersion. Applying a linear stability analysis and stochastic calculus, we show that the MI gain spectrum reads as the maximal eigenvalue of a constant effective matrix. In the limiting cases of small or large fluctuations, we give explicit expressions for the MI gain spectra. In the general configurations, we give the explicit form of the effective matrix and numerically compute the maximal eigenvalue. In the anomalous dispersion regime, polarization dispersion widens the unstable bandwidth. Depending on the type of variations of the birefringence parameters, polariza…
High-order harmonic generation in fullerenes using few- and multi-cycle pulses of different wavelengths
2012
We present the results of experimental and theoretical studies of high-order harmonic generation (HHG) in plasmas containing fullerenes using pulses of different duration and wavelength. We find that the harmonic cutoff is extended in the case of few-cycle pulses (3.5 fs, 29th harmonic) compared to longer laser pulses (40 fs, 25th harmonic) at the same intensity. Our studies also include HHG in fullerenes using 1300 and 780 nm multicycle (35 and 40 fs) pulses. For 1300 nm pulses, an extension of the harmonic cutoff to the 41st order was obtained, with a decrease in conversion efficiency that is consistent with theoretical predictions based on wave packet spreading for single atoms. Theoreti…
Spatial Soliton Dynamics in Two-Dimensional Quadratic Photonic Crystals
2007
We present a theoretical and experimental investigation of soliton dynamics associated to twin-beam second harmonic generation in a purely nonlinear two-dimensional planar photonic lattice in LiNbO3.