Search results for "Raman amplification"
showing 7 items of 17 documents
Optical rogue-wave-like extreme value fluctuations in fiber Raman amplifiers
2008
International audience; We report experimental observation and characterization of rogue wave-like extreme value statistics arising from pump-signal noise transfer in a fiber Raman amplifier. Specifically, by exploiting Raman amplification with an incoherent pump, the amplified signal is shown to develop a series of temporal intensity spikes whose peak power follows a power-law probability distribution. The results are interpreted using a numerical model of the Raman gain process using coupled nonlinear Schrödinger equations, and the numerical model predicts results in good agreement with experiment.
Experimental signatures of extreme optical fluctuations in lumped Raman fiber amplifiers
2012
International audience; In this work, we experimentally investigate several temporal and spectral methods to highlight extreme fluctuations which can develop during the Raman amplification of an ultrashort pulse train. Forward and backward pumping schemes are compared to dual pass configurations.
Raman-assisted three-wave mixing of non-phase-matched waves in optical fibres: application to wide-range frequency conversion
2001
International audience; We analyse theoretically and experimentally the Raman-assisted parametric coupling between non-phase-matched waves propagating in normally dispersive single-mode fibres. We perform a careful analysis of the wave-coupling behaviour, which shows that scalar and vector three-wave mixing (TWM) interactions induce a relatively small periodic power flow between a central-frequency pump at frequency ω0 and a pair of up-shifted (anti-Stokes) and down-shifted (Stokes) sidebands at frequencies View the MathML source and View the MathML source, respectively. For sufficiently high pump powers, the stimulated Raman scattering enters into play, causing a unilateral transfer of ene…
New concepts based on nonlinear polarization effects and Raman amplification in optical fibers
2009
We report a theoretical analysis and experimental demonstration of a polarization attraction process at telecommunication wavelengths in isotropic optical fibers. The combined effects of polarization attraction and Raman amplification are also presented.
New developments in the study of optical parabolic pulses in normally dispersive fibers
2011
International audience; We report two recent studies dealing with the evolution of parabolic pulses in normally dispersive fibers. On the one hand, the nonlinear reshaping from a Gaussian intensity profile towards the asymptotic parabolic shape is experimentally investigated in a Raman amplifier. On the other hand, the significant impact of the fourth order dispersion on a passive propagation is theoretically discussed: we numerically demonstrate flat-top, coherent supercontinuum generation in an all-normal dispersion-flattened photonic crystal fiber. This shape is associated to a strong reshaping of the temporal profile what becomes triangular.
Experimental parabolic pulse generation with an active dispersion decreasing fiber
2008
We experimentally demonstrate the use of an hybrid configuration to generate parabolic pulses. We combine dispersion decrease with distributed gain. This leads to several benefits on the parabolic generated pulses compared with a passive configuration.
Simultaneous polarization attraction and Raman amplification of a light beam in optical fibers
2012
International audience; In this paper, we demonstrate that it is possible to combine both Raman amplification and polarization attraction of a signal wave in a single optical fiber by means of a counterpropagating scheme. Experiments were performed near 1550 nm in a continuous wave regime and by means of a 10 Gbit ∕ s return-to-zero signal injected in a 20 kmlong low polarization mode dispersion optical fiber. Complete repolarization and 6.7 dB amplification of the signal wave was achieved by injecting a 850 mW, 1480 nm counterpropagating polarized pump wave.