Unified description of ultrafast stimulated Raman scattering in optical fibers
نویسندگان
چکیده
Coupled nonlinear equations that describe the nonlinear process of stimulated Raman scattering in optical fibers are derived. These equations account in a unified manner for the Raman amplification, the Stokes generation, the induced self-frequency shift, and the interpulse stimulated Raman-scattering-induced crossfrequency shift. The equations reduce to a well-known form for relatively wide picosecond pump pulses. Using these equations, we show theoretically that the effects of cross-phase modulation, self-frequency shift, and cross-frequency shift cause two optical pulses copropagating in the anomalous dispersion regime of the fiber to shed some of their energy and evolve into a narrower soliton, which has a higher frequency shift than a single propagating soliton. It is also shown that the self-frequency shift of femtosecond pulses is detrimental to Raman generation. As the input pulse width is reduced, the spectrum of the pulse shifts by an amount comparable with the Raman shift. The shift increases continuously with propagation at such a rapid rate that the Stokes pulse has no time to build up from noise to significant energy levels. © 1996 Optical Society of America.
منابع مشابه
Cross-phase modulation and induced focusing due to optical nonlinearities in optical fibers and bulk materials
Cross-phase modulation (XPM) and induced focusing occur when copropagating ultrafast pulses interact in a nonlinear medium. XPM and induced focusing are investigated as new techniques to control the spectral, temporal, and spatial properties of ultrafast pulses with femtosecond time response. In this paper we review our most recent measurements on (1) induced spectral broadening in BK7 glass, (...
متن کاملNonlinear phenomena in optical fibers
4. Nonlinear phenomena 4.1. Second-order nonlinear phenomena 4.2. Third-order nonlinear phenomena 4.3. Stimulated Raman scattering 4.4. Stimulated Brillouin scattering 4.5. Four-wave mixing (FWM) 4.6. Self-phase modulation (SPM) 4.7. Cross phase modulation (XPM) 4.8. Theoretical description of GVD phenomenon and self-phase modulation 4.8.1. Nonlinear Schrödinger equation 4.8.2. Inclusion of the...
متن کاملInvestigation of Scalar Modulation Instability in the Presence of Raman Scattering in Photonic Crystal Fibers
In this paper, by including Raman scattering in the coupled-mode equations, the scalar modulation instability in photonic crystal fibers is investigated. The evolution of the pump, Stokes and anti-Stokes waves along the fiber as well as the conversion efficiency for two cases, with and without Raman effect, are studied. The effect of anti-Stokes seed and the pump depletion on the evolution of S...
متن کاملWide control of the group velocity of light in optical fibers
We demonstrate experimentally that a wide control of the group velocity of light can be achieved in conventional optical fibers by use of the stimulated Brillouin scattering effect. Zero, negative and large positive group indices can be readily achieved with a simple experiment. 2005 Optical Society of America OCIS codes: (290.5900) Scattering, stimulated Brillouin; (060.4370) Nonlinear optic...
متن کاملSpontaneous Nonlinear Scattering Processes in Silica Optical Fibers
When light travels in a optical fiber, a fraction of its total power is always scattered to other wavelengths (or polarization) due to material non linearity. Whether that scattering is weak or strong, desirable or not, depends on the situation. One distinguishes (i) scattering stimulated by the presence of a seed wave (at another wavelength or polarization), (ii) spontaneous scattering, and (i...
متن کامل