Search results for "Four-wave mixing"
showing 10 items of 97 documents
Two frequency oscillation of a photorefractive oscillator as a perturbation of the mirrorless oscillation
2010
We consider the properties of the non-degenerate two frequency regime of oscillation of the semi-linear photorefractive oscillator and analyze its relation with the mirrorless oscillation. We consider the oscillator with or without a frequency shifted feedback by a vibrating mirror. This study shows that these two apparently different phenomena are closely related. We conclude from the obtained results that the two frequency oscillation can be considered as a perturbation of the mirrorless oscillation.
Nonlinear dynamics induced by optical shocks formation
2006
This paper reports on recent studies suggesting that optical shocks can rule the dynamics of cw (or quasi-cw) optical field propagating in glass when common phenomena such as four-wave mixing in fibers or catastrophic self-focusing in bulk are considered. The post-shock oscillations evolve into colliding dark solitons that determine the output pattern in a non-recurrent fashion. This scenario based on the defocusing nonlinear Schrodinger equation and its reduction to a hydrodynamical model is substantially confirmed by our experimental data consisting of recorded output spectra and temporal patterns retrieved from SHG-FROG traces. Numerical results also indicate that, during self-focusing, …
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.
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…
Stable coupled conjugate solitary waves in optical fibers.
1998
Four-wave mixing of an intense continuous-wave pump beam with an ultrashort soliton signal in an optical fiber is theoretically analyzed. A novel class of stable two-color coupled solitary waves is found. These vector parametric solitons represent the optimal frequency conversion of an ultrashort pulse. © 1998 Optical Society of America.
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.
Triple resonant four-wave mixing boosts the yield of continuous coherent vacuum ultraviolet generation.
2012
Efficient continuous-wave four-wave mixing by using three different fundamental wavelengths with individual detunings to resonances of the nonlinear medium is shown. Up to 6 μW of vacuum ultraviolet light at 121 nm can be generated, which corresponds to an increase of three orders of magnitude in efficiency. This opens the field of quantum information processing by Rydberg entanglement of trapped ions.
Nonlinear dynamics of a semilinear photorefractive oscillator
2001
The experimental study of the dynamics of an empty coherent semilinear photorefractive oscillator is reported. It is shown that starting from a certain coupling strength the oscillation occurs with two frequencies shifted symmetrically with respect to the frequency of the pump wave. The threshold of bifurcation in oscillation spectrum depends on pump intensity ratio.
Triply resonant coherent four-wave mixing in silicon nitride microresonators
2015
The generation of multiple tones using four-wave mixing (FWM) has been exploited for many applications, ranging from wavelength conversion to frequency comb generation. FWM is a coherent process, meaning that its dynamics strongly depends on the relative phase among the waves involved. The coherent nature of FWM has been exploited for phase-sensitive processing in different waveguide structures, but it has never been studied in integrated microresonators. Waveguides arranged in a resonant way allow for an effective increase in the wavelength conversion efficiency (at the expense of a reduction in the operational bandwidth). In this letter, we show that phase shaping of a three-wave pump pro…
Oscillation spectra of semilinear photorefractive coherent oscillator with two pump waves
2002
The transition of the single-frequency oscillation of a semilinear photorefractive coherent oscillator for sufficiently large coupling strengths into two-frequency oscillation is predicted and is observed experimentally. The critical value of coupling strength at which the bifurcation occurs is a function of pump-intensity ratio and cavity losses. For certain combinations of these parameters, the critical coupling strength for spectrum bifurcation becomes smaller than the threshold coupling strength: in these cases double-frequency oscillation appears at the threshold. The supercritical bifurcation in the oscillation spectrum is analogous to the second-order phase transition.