Search results for "Nonlinear optics"
showing 10 items of 482 documents
Direct theoretical evidence of nuclear motion in H+2by means of high harmonic generation
2007
The numerical solution of the time-dependent Schro ̈dinger equation for vibrating hydrogen molecular ions in many-cycle laser pulses shows that high- order harmonic generation is sensitive to laser-induced molecular vibrations. In particular, the odd harmonic lines in the emitted spectra are surrounded by additional regular peaks whose spacing is given by the vibrational frequency of the nuclei motion. Analytical theory relates these satellite peaks to the molecular vibrations in terms of an approximated effective potentials. These results are not affected by the dimensionality of the system.
Laser driven parametric amplification of xuv and soft-x-rays in neutral gases
2010
We present the first theoretical description and also experimental evidence for the amplification of XUV and soft-X-ray radiation by parametric stimulated emission in neutral gases driven by near-IR laser pulses reaching small-signal-gain up to 8000.
Buffering optical topological data using passive Kerr resonators
2018
We experimentally demonstrate the existence of dissipative polarization domain walls, in a normally dispersive Kerr resonator. Through deterministic manipulation of the laser driving the resonator, we achieve systematic excitation and locking of the domain walls.
Dissipative soliton resonance in a passively mode-locked fiber laser
2011
The phenomenon of dissipative soliton resonance (DSR) predicts that an increase of pulse energy by orders of magnitude can be obtained in laser oscillators. Here, we prove that DSR is achievable in a realistic ring laser cavity using nonlinear polarization evolution as the mode-locking mechanism, whose nonlinear transmission function is adjusted through a set of waveplates and a passive polarizer. The governing model accounts explicitly for the arbitrary orientations of the waveplates and the polarizer, as well as the gain saturation in the amplifying medium. It is shown that DSR is achievable with realistic laser settings. Our findings provide an excellent design tool for optimizing the mo…
Polarization instability in anisotropic-cavity degenerate four-wave mixing
2000
Abstract The emission and stability properties of a plane-wave model of intracavity degenerate four-wave mixing including self- and cross-phase modulation are studied. A Kerr medium inside an anisotropic cavity in which a linearly polarized field is injected is considered. Cavity anisotropy leads to qualitative new phenomena such as a subcritical polarization instability.
Spatial Solitons in Quadratic 2D Nonlinear Photonic Crystals
2007
We report on the first investigations into parametric solitary-wave formation in 2D nonlinear photonic crystals and present experimental results obtained in an hexagonally poled LiNbO3 waveguide designed for twin-beam second harmonic generation at telecom wavelengths.
Spontaneous polarization induced by natural thermalization of incoherent light
2008
We analyze theoretically the polarization properties of a partially coherent optical field that propagates in a nonlinear Kerr medium. We consider the standard model of two resonantly coupled nonlinear Schrödinger equations, which account for a wave-vector mismatch between the orthogonal polarization components. We show that such a phase-mismatch is responsible for the existence of a spontaneous repolarization process of the partially incoherent optical field during its nonlinear propagation. The repolarization process is characterized by an irreversible evolution of the unpolarized beam towards a highly polarized state, without any loss of energy. This unexpected result contrasts with the …
Bifurcations and multiple-period soliton pulsations in a passively mode-locked fiber laser
2004
The multiple-period pulsations of the soliton parameters in a passively mode-locked fiber laser were discussed numerically and experimentally. It was found that the pulse acquired a periodic evolution that was not related to the round-trip time and consisted of many round trips. The macroperiodicity existed independently or in combination with other periodicity such as period doubling, tripling etc. Analysis shows that the new periods in the soliton modulation appear at bifurcation point related to certain points related to certain values of the cavity parameters.
Four-wave-mixing coherent oscillator with frequency shifted feedback and misaligned pump waves.
2009
The effect of the pump waves misalignment on the oscillation spectra and oscillation intensity of a semilinear photorefractive oscillator is studied numerically and compared with the results of the experiment performed with a KNbO3:Fe,Ag crystal.
Phase joint transform sequential correlator for nonlinear binary correlations
2005
We study the performance of nonlinear optical correlations using a joint transform correlator that operates in phase-only spatial light modulation at input joint transform plane. Amplitude input nonlinear optical time sequential correlations have shown better discrimination and noise robustness than conventional linear correlations. Those nonlinear correlations are based on decomposing the reference and the target into binary slices and to add the contribution of all linear correlations between them. Those correlations can be easily implemented using a conventional joint transform correlator. However, the system has poor efficiency and low cross-correlation peak intensity, mainly because of…