共查询到20条相似文献,搜索用时 31 毫秒
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Resonant third harmonic generation of a sub-millimeter wave in n-InSb waveguide embedded with a density ripple is investigated. The non-linearity arises through the modulation of free electron mass while the ripple accounts for the phase mismatch. The efficiency of the third harmonic generation is large. However, as the plasma frequency increases the attenuation rate of the third harmonic increases and the third harmonic efficiency decreases as (ωpb/c) is raised. 相似文献
3.
Spectral modulation of third-harmonic generation by molecular alignment and preformed plasma
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We demonstrate spectral modulation of third-harmonic generation from molecular alignment effects. The third harmonic spectrum is broadened or narrowed under different influences of cross-phase modulations originating from various molecular alignment revivals. Furthermore, the spectrum and spatial distribution of the generated third harmonic pulse change dramatically in the presence of a preformed plasma. Under the influence of a preformed plasma, a narrower third harmonic spectrum is observed, and the conical third-harmonic pulse increases while the axial part decreases. The investigation provides an effective method to modulate the spectral characteristic and spatial distribution of third-harmonic generation from intense femtosecond filament. 相似文献
4.
本文报道了利用光脉冲在10m单模光纤中传播所产生的自相位调制(SPM)、互相位调制(XPM)、群速色散(GVD)和受激喇曼散射(SRS)的共同作用,实现光脉冲光谱和时间加宽,经光栅对线性啁啾补偿后,将脉宽15ps的1.06μm光脉冲压缩至小于6ps,能量大于100nJ,压缩比>2.5。 相似文献
5.
A. O. Korotkevich S. A. Nikitov 《Journal of Experimental and Theoretical Physics》1999,89(6):1114-1119
This paper explains the modulation instability of two surface magnetostatic spin waves simultaneously propagating in a ferromagnetic
film. Self-modulation of the spin waves appears when their power reaches a threshold, and this is a sign of cross-phase modulation.
The parameters of the unstable process are calculated, and the gains of the perturbation amplitudes are determined. The results
published earlier on the experimental detection of the cross-phase modulation of spin waves are explained.
Zh. éksp. Teor. Fiz. 116, 2058–2068 (December 1999) 相似文献
6.
Rajneesh Randhawa Surinder Singh J. S. Sohal R. S. Kaler 《Fiber and Integrated Optics》2013,32(2):154-169
Abstract We have simulated, for the first time, wavelength converter for future broadcast networks at 40 Gb/s using low-cost semiconductor optical amplifiers. The performance analysis is carried out for an all-optical frequency converter based on cross-phase modulation in two semiconductor optical amplifiers arranged in a Mach-Zehnder interferometer configuration to evaluate the efficiency of conversion. The results, evaluated analytically for input, return to zero signal at a bit rate of 40 Gb/s show that conversion is possible over a wavelength separation of 1 nm between the pump and the input wavelength. Increasing the driving current can decrease the cross-phase modulation effect. The cross gain modulation scheme shows extinction ratio degradation for conversion to longer wavelengths. 相似文献
7.
We numerically and experimentally show the existence of multicolor vector spatial solitons in a Kerr planar waveguide through the combined effects of cross-phase modulation, four-wave mixing, and stimulated Raman scattering. Mutual spatial guiding of the Raman-Stokes, anti-Stokes, and pump waves is achieved in the high-conversion regime mainly by cross-phase modulation and phase-matched four-wave mixing induced by a power imbalance between Stokes and anti-Stokes components, leading to the generation of a clear-cut sech-shape three-frequency spatial soliton. 相似文献
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Yi Zhang Shuyu Yang Lan Rao Wenjing Li Jinhui Yuan Xiangjun Xin Chongxiu Yu 《Optics Communications》2010,283(15):3043-3048
Nondegenerate Four Wave Mixing (FWM) process in a silicon waveguide is influenced by two photon absorption (TPA), TPA induced free carrier absorption (FCA) besides self-phase modulation (SPM), cross-phase modulation (XPM), SRS, GVD and linear scattering losses. Influences of pump parameters of the dual-pump parametric amplifier (OPA) in the silicon waveguide on gain spectrum and noise figure are numerically investigated. Compared with single-pump configuration, dual-pump silicon OPA indicates a flat gain and noise figure. Then impact of waveguide dispersion on bandwidth and ripples for dual-pump silicon optical parametric amplifiers is discussed. Optimal pump configurations are evaluated. The results show that polarization independent net gain of silicon OPA can be achieved by using circular and orthogonally polarized pump. 相似文献
10.
We report visible supercontinuum generation initiated by the second harmonic generation obtained in a germanium-doped microstructured optical fiber after optical poling processing. The visible spectral broadening is due to a cross-phase modulation effect between the generated IR solitons and the second harmonic (532 nm) of the 1064 nm pump wave. The 400-650 nm white-light emission is obtained on the fundamental propagation mode of the fiber. 相似文献
11.
A study is made of the channeling of atoms in a narrowing hollow waveguide carrying on its inner surface a surface wave with
positive detuning for the absorption line of an atom. The inelastic reflection of atoms from the surface light wave and the
convergent geometry of the waveguide make it possible to decrease the temperature and increase the phase density of an ensemble
of atoms introduced continuously into the hollow convergent waveguide from a magnetooptic trap, by a factor of 105. It is suggested that such a waveguide be used to study collective phenomena in quantum-mechanical systems with a high density
(Bose-Einstein condensate) and as a high-luminosity coherent source of cold atoms.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 10, 763–767 (25 May 1996) 相似文献
12.
Numerical solutions are obtained of the full self-consistent system of equations for the counter, rotating polarization components of the field of a short optical pulse propagating in a nonlinear birefringent fiber and in the ensemble of the energy-level degenerate doped resonance atoms implanted in the fiber material. In every cross section of the fiber, the ellipticity of the polarized wave experiences a complex evolution in time accompanied by rapid changes of the azimuthal angle due to the interplay of the dispersion and the Kerr nonlinear self-and cross-phase modulation. The reciprocal effect of the impurities on the traveling pulse causes oscillations of the pulse envelope that can completely distort the shape of the input signal, while the resonance absorption can drive the birefringence process from the nonlinear regime back to the linear one. 相似文献
13.
S. O. Elyutin A. I. Maimistov I. R. Gabitov 《Journal of Experimental and Theoretical Physics》2010,111(1):157-169
The propagation of the pump and its third harmonic pulses in a cubically nonlinear medium is considered theoretically, provided
that the linear properties of the medium are characterized by a negative refractive index at the pump frequency and a positive
refractive index at the harmonic frequency. For low-intensity interacting waves, the pump and third harmonic pulses propagate
in opposite directions, but sufficiently intense pulses can produce a simulton—a solitary two-frequency wave that propagates
in a certain direction as a single whole. The system of equations is investigated numerically for a model that, apart from
the harmonic generation, includes the second-order group velocity dispersion and the nonlinear self- and cross-phase modulations
of the interacting waves. The separation of the pump and harmonic pulses due to the difference in the directions of their
group velocities and peculiarities of the Manley-Rowe relation for parametric processes in metamedia are discussed. 相似文献
14.
We have observed extreme nonlinear optical phenomena produced by intense midinfrared (MIR) pulses in semiconductors. These phenomena include multiple off-resonance optical sidebands (up to +/-3 MIR photons interacting with a near-infrared photon), multiple MIR harmonics (up to the seventh harmonic), and significant broadening and modification of MIR harmonic spectra. The generation of these extreme MIR nonlinear optical phenomena is primarily aided by cross-phase modulation. 相似文献
15.
W. B. Fraga J. W. M. Menezes C. S. Sobrinho A. C. Ferreira G. F. Guimar?es A. W. Lima Jr. A. F. G. F. Filho H. H. B. Rocha K. D. A. Sabóia F. T. Lima J. M. S. Filho A. S. B. Sombra 《Optical and Quantum Electronics》2009,41(2):121-130
In this paper, we have presented a numerical analysis of the stability of optical bullets (2 + 1), or spatiotemporal solitons (2 + 1), in a planar waveguide with cubic–quintic nonlinearity. The optical spatiotemporal solitons are the result of the balance between the nonlinear parameters, of dispersion (dispersion length, L D) and diffraction (diffraction length, L d) with temporal and spatial auto-focusing behavior, respectively. With the objective of ensure the stability and preventing the collapse or the spreading of pulses, in this study we explore the cubic–quintic nonlinearity with the optical fields coupled by cross-phase modulation and considering several values for the non linear parameter α We have shown the existence of stable light bullets in planar waveguide with cubic–quintic nonlinearity through the study of spatiotemporal collisions of the light bullets. 相似文献
16.
Shtaif M 《Optics letters》1998,23(15):1191-1193
The effect of intensity distortion induced by cross-phase modulation in dispersive optical fibers is studied. It is shown that, in most configurations in which distortions that are due to cross-phase modulation can become significant to optical communications, the effect of cross-phase modulation can be described with excellent accuracy by simple analytical expressions. The presented analysis also suggests that intensity distortions owing to cross-phase modulation can be efficiently reduced by linear dispersion compensation. 相似文献
17.
A comprehensive technique has been used to detect diffraction from the second and the third nonlinear spatial harmonic components, along with the fundamental harmonic of volume photorefractive gratings recorded in a channel waveguide in a LiNbO3 substrate. For the first time to our knowledge, efficient diffraction from the higher spatial harmonic components of a photorefractive grating has been detected in reflection geometry. The dependence of a Bragg wavelength shift on the order of nonlinearity is also reported. 相似文献
18.
I. O. Zolotovskii D. A. Korobko V. A. Lapin D. I. Sementsov 《Optics and Spectroscopy》2016,121(2):256-262
The conditions for the onset of modulation instability of wave packets in an optical waveguide in the presence of the traveling refractive index wave are investigated. An expression governing the growth rate of a small harmonic perturbation at the early development stage of the modulation instability is obtained. Based on numerical analysis, the behavior of the wave packet at the developed modulation instability stage is studied for different parameters of the waveguide and the refractive index wave. 相似文献
19.
We study the Kerr nonlinearity associated with cross-phase modulation based on electromagnetically induced transparency in asymmetric double quantum wells. It is shown that, different from atomic system, not only the nonlinear dispersion and absorption but also the linear absorption depends on the relative phase of the laser fields because of the Fano interference. By choosing the parameters appropriately, large cross-phase modulation with nearly vanishing two-photon absorption, even π phase shift with single photon level, could be achieved in the asymmetric quantum wells. 相似文献
20.
We describe a novel performance optimization method for all-optical amplitude reshaping via degenerated four-wave mixing(FWM) in highly nonlinear optical fiber.The proposed optimization method is achieved by judiciously configuring the FWM operational condition and exploiting the nonlinear phase shift induced by self-and cross-phase modulations to properly influence the FWM conversion efficiency.Through the proposed scheme,fully functional and prevailing reshaping performance,including significant amplitude jitter suppression and extinction ratio improvement,is obtained within a single FWM stage.Results of the present theoretical calculation and numerical simulation verify the feasibility and advantages of the proposed scheme. 相似文献