Search results for "Instability"

Modulational Instability and Stimulated Raman Scattering in Normally Dispersive Highly Birefringent Fibers

2001

Abstract The nonlinear interaction of two laser beams in normally dispersive highly birefringent optical fibers leads to a large set of fascinating physical effects such as modulational instability (MI) and stimulated Raman scattering (SRS). These two nonlinear phenomena have a positive role as a mechanism for the generation of short optical pulses and represent a drawback in fiber-optics transmissions. Indeed, we will show that an induced process of modulational instability may be exploited for the generation of THz train of vector dark solitons. The technique of frequency-resolved optical gating is used to completely characterize the intensity and phase of the dark soliton trains. On the …

Dark three-sister rogue waves in normally dispersive optical fibers with random birefringence

2014

11 pags.; 4 figs.; OCIS codes: (190.3100) Instabilities and chaos; (190.4370) Nonlinear optics, fibers; (060.5530) Pulse propagation and temporal solitons.

Solitons in Optical Fibers

1996

In the near future nonlinear optics should probably revolutionize the world of telecommunications and computer technologies. With lasers producing highintensity and short-duration optical pulses, it is now possible to probe the interesting, and potentially useful, nonlinear effects in optical systems and waveguides. Among the guiding structures, the optical fiber is an interesting (Gloge 1979) and important device (Mollenauer and Stolen 1982; Doran and Blow 1983). In an optical transmission system using linear pulses, the bit rate of transmission is limited by the dispersive character of the material, which causes the pulse to spread out an eventually overlap to such an extend that all the …

Suppression of sideband frequency shifts in the modulational instability spectra of wave propagation in optical fiber systems

2007

International audience; In standard optical fibers with constant chromatic dispersion, modulational instability (MI) sidebands execute undesirable frequency shifts due to fiber losses. By means of a technique based on average-dispersion decreasing dispersion-managed fibers, we achieve both complete suppression of the sideband frequency shifts and fine control of the MI frequencies, without any compromise in the MI power gain.

Cross-phase modulational instability induced by Raman scattering in highly birefringent fiber

2013

We report experimental and theoretical studies of Raman-induced cross-phase modulational instabilities (XPMI) in a high-birefringence, normally dispersive optical fiber. Experimental results reveal that the Raman-Stokes wave, generated by a quasi-CW pump beam, interacts with the latter to create a novel type of XPMI sidebands. These sidebands are characterized by a narrow gain bandwidth. The sideband frequencies are well reproduced by a linear stability analysis as well as by full numerical solutions of the coupled generalized nonlinear Schrödinger equations.

Observation of modulational instability induced by velocity-matched cross-phase modulation in a normally dispersive bimodal fiber

2008

We demonstrate experimentally the existence of cross-phase-modulation-induced modulational instability in the absence of group-velocity mismatch between the interacting nonlinear dispersive waves. The experiment is performed by means of a normally dispersive isotropic bimodal fiber. The group-velocity mismatch between the fundamental and the first-order modes that constitute the two interacting waves is controlled by wavelength tuning. A strong power dependence of the modulational instability spectra is observed near the condition of group-velocity matching.

Critical behavior with dramatic enhancement of modulational instability gain in fiber systems with periodic variation dispersion

2008

International audience; We analyze modulational instability (MI) of light waves in fiber systems with periodically varying dispersion. The dispersion fluctuation generates special waves, called nonconventional MI sidebands, which are shown to be highly sensitive to two fundamental system parameters. The first one is the average dispersion of the system. Surprisingly, the second parameter turns out to be the mean value of the dispersion coefficients of the two types of fibers of the system, which is then called “central dispersion.” These two parameters are used to control and optimize the MI process. In particular, we establish the existence of a critical region of the central dispersion at…

Higher-order modulation instability in fiber optics

2012

We report on analytical, numerical and experimental studies of higher-order modulation instability in fiber optics. This new form of instability arises from the nonlinear superposition of elementary instabilities and manifests as complex, yet deterministic temporal pulse break-up dynamics. We use the Darboux transformation to analytically describe the process and compare with experiments. In particular, we show how suitably low frequency modulation on a continuous wave field allows for the excitation of higher-order modulation instability through cascaded four-wave mixing.

Observation of Modulational Instability induced by a dynamical Bragg grating in an optical fiber

2001

We present a detailed experimental study on Bragg Modulational Instability in a highly birefringent fiber. The originality of our scheme is that the index modulation is obtained through cross phase modulation with a beating wave.

Multimode instability in ring fiber lasers

1999