Search results for "fiber"

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.

Quantized separations of phase-locked soliton pairs in fiber lasers

2003

Quantized separations of phase-locked soliton pairs in fiber lasers were presented. The relation between the Kelly sidebands and the quantized separations between solitons was confirmed. Simulation results showed that the solitons can see each other at relatively larger distances than they would in the absence of radiation.

Multimode equivalent network representation for planar junctions involving elliptical waveguides

1996

Multimode emission in inhomogeneously broadened ring lasers

2001

The threshold for multilongitudinal-mode emission in inhomogeneously broadened ring lasers is analytically investigated. In the homogeneous limit the multimode instability corresponds to the classical Risken–Nummedal–Graham–Haken instability. It is found that by increasing the inhomogeneous linewidth, the instability threshold is decreased and the growth of high-frequency side modes is favored. In the limit where the population-inversion decay rate γ‖ is much smaller than the polarization decay rate γ⊥ (class B lasers), analytical expressions for the instability threshold are found, which are then generalized to three-level lasers for a comparison with experimental results obtained with erb…

Second harmonic generation in multimode graded-index fibers: spatial beam cleaning and multiple harmonic sideband generation

2017

We study experimentally and numerically the spectral and spatial dynamics of second harmonic generation in an all-optically poled multimode graded-index fiber. In contrast with poled single-mode fibers, in a multimode graded-index fiber a pump can generate a series of sharp sidebands around its second harmonic (SH) that originate from the sub-millimetric periodic evolution of the intensity at the fundamental frequency. The mutual interaction between the fundamental and its SH may also strongly affect the spatial distribution of guided light for both colors: when increasing the pump power, both fundamental and SH output beams evolve from disordered multimode speckles into two bell-shaped bea…

Generalized rate equations for multimode lasers

2003

Abstract A generalized rate equations model for class B lasers outside the uniform field limit is presented. This model allows to correctly describe the Risken–Nummedal–Graham–Haken instability and its associated multimode dynamics. When parameters suitable for fiber lasers – where the instability has been observed – are adopted, the computation time is shown to be greatly reduced with respect to the complete model based on the full set of Maxwell–Bloch (MB) equations.

All-Optical Polarization Control for Telecom Applications

2015

We describe a phenomenon of self-organization of the light state-of-polarization in optical fibers based on a nonlinear cross-polarization interaction between an incident signal and its backward replica. Several proof-of-principles for telecom applications are reported.

Multimode instability in inhomogeneously broadened class-Bring lasers: Beyond the uniform-field limit

2001

The multimode emission threshold of class-$B$ ring lasers is analytically investigated taking into account the localized nature of the cavity losses and the inhomogeneous broadening of the amplifying medium. This analysis finds a relevant application to erbium-doped fiber lasers (EDFL's). The main conclusion is that the predictions of the simplest models are deeply modified both quantitatively and qualitatively. Thus, any attempt to interpret multimode emission in EDFL's must incorporate the two considered factors. Two main results are: (i) While in homogeneously broadened lasers instabilities are inhibited for values of the mirrors' reflectivity $\mathcal{R}l0.54ca,$ this limitation disapp…

Observation of Manakov polarization modulation instability in the normal dispersion regime of randomly birefringent telecom optical fiber

2014

Fine Thermal Structure of a Coronal Active Region

2007

著者人数：12名