共查询到20条相似文献,搜索用时 875 毫秒
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Cristiani I. Romagnoli M. France F. Paoletti A. Socci L. 《Photonics Technology Letters, IEEE》1998,10(11):1557-1559
We show a new type of actively mode-locked fiber laser that, despite the 2.5-km-long cavity and the average group-velocity dispersion of -20 ps2/km, generates solitons with duration of 2÷4 ps, 1-GHz repetition rate and timing jitter of 0.7 ps. Such short solitons are generated in an inter-resonance condition that favors a highly stable propagation regime. Soliton duration and timing jitter are both controlled by the self-frequency-modulation due to the background radiation emitted by the solitons themselves 相似文献
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光学孤子是指一种通过非线性折射率势阱维持脉冲形状不变的光波,它广泛存在于光纤、飞秒激光器、参量振荡器等系统中。近年来,人们在相干泵浦下的高Q值微腔中也观测到了光孤子,这为研究光孤子性质提供了新的实验平台。又因为微腔光孤子在频域上对应高重频的光学频率梳,微腔光孤子的诞生也极大地推动了小型化光学频率梳的发展。微腔光孤子频率梳已经可以实现自参考锁定;这使得片上集成的光频合成器、光原子钟、波分复用光源、微腔光谱仪、微腔激光雷达等众多应用成为了可能。文中介绍了微腔光孤子的产生基础,特别是光孤子相互作用相关的研究,还讨论了基于微腔的双光梳测量在高速成像与中红外气体光谱分析上的应用。 相似文献
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Michaelis D. Peschel U. Etrich C. Lederer F. 《Quantum Electronics, IEEE Journal of》2003,39(2):255-268
We derive mean-field equations for intra-cavity second-harmonic generation. Based on this model, we show that a variety of quadratic cavity solitons can exist. Highly symmetric and resting cavity solitons originate from primary bifurcations of the underlying stationary plane wave solutions. For certain control parameters, these solutions may undergo a secondary bifurcation leading to symmetry-reduced and/or moving/breathing quadratic cavity solitons. In particular, we predict for the first time the existence of triangular cavity solitons and derive a criterion for an nonequilibrium Ising-Bloch transition. 相似文献
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Communications engineers are learning to create an electromagnet wave at will, to transmit information. This wave, the optical soliton, is the subject of astounding recent developments in nonlinear optics and lasers. The author describes the principles behind the use of solitons in optical communications and shows that in the context of such communications the most important property of solitons is that they are extremely stable. Not only do they not disperse, but an encounter with a perturbation (e.g. a joint in optical fibre) will usually leave the soliton unaltered 相似文献
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We discuss the existence and the stability properties of spatial solitons, which are excited in externally driven nonlinear resonators. First, we give a short derivation of the basic equations we use to describe the field dynamics in a Fabry-Perot cavity. Then we show how the range of existence of cavity solitons is related to the stability properties of respective continuous wave solutions. Theoretical predictions are illustrated by numerical results and experimental findings. 相似文献
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提出了有偏压光伏光折变晶体中存在着明暗矢量孤子,它起源于对外电场的非均匀空间屏蔽和光伏效应.当光伏效应为零时,这些明暗矢量孤子就转化为明暗矢量屏蔽孤子,其物理系统就转化为明暗矢量屏蔽孤子的物理系统;当外电场为零时,这些明暗矢量孤子预言了明暗矢量光伏孤子,其物理系统预言了明暗矢量光伏孤子的物理系统.应用光束传播的方法讨论了这些明暗矢量孤子的稳定性.结果表明,当σ> 0 和(β+α-δ) > 0 时,在(β+α-δ)小于某一值的区域内,这些明暗矢量孤子是稳定的;其中σ为控制两光束强度的参数,β为与外偏压有关的参数,α和β为与晶体的光伏系数有关的参数;当σ<0和(β+α-δ) <0时,在(β+α-δ)大于某一值的区域内,这些明暗矢量孤子也是稳定的. 相似文献
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We present a theory of the soliton laser which examines how an external optical fiber enables a laser to produce shorter pulses than it could produce alone. We begin by discussing a phenomenological laser model which shows how the lower limit to the mode-locked pulse width can arise. This model is coupled to an external optical fiber cavity, into which a part of the output beam is launched. The returning pulse from the fiber cavity is then mixed with a circulating pulse in the laser at the output mirror. We have found stable solutions which are nearly periodic in the external cavity. We also find more than one solution for a given set of model parameters, depending on the initial conditions. The radiation (non-soliton) part of the propagation in the optical fiber cannot be ignored. It acts as a buffer between the tendency of the fiber to produce solitons, and the fact that a pure soliton is not an exact fixed point of the laser model. 相似文献
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为了得到两个或多个光折变屏蔽光伏亮孤子之间相互作用结果,采用数值方法分析了两个或多个屏蔽光伏亮孤子之间的相互作用。两同相孤子作用时表现为相互吸引,并伴有融合现象,且孤子融合发生时的作用距离随着孤子初始间距的增大而增大;两反向孤子相互排斥,且排斥作用随孤子初始间距的减小而增强;当两孤子的相位差位于区间(0,π)和(-π,0)中时,其相互作用过程中伴有能量的转移,两区间中能量转移方向相反。多个同向孤子相互作用时,不同于两个孤子周期的融合和分开,而是在整体吸引过程中发生孤子的逐步融合作用。当中间孤子与两边孤子的相位差是π/2时,多个孤子之间存在能量转换。而邻近相互反相的多个孤子相互作用时,能保持很好的稳定性传播。结果表明,这种相对相位控制下的两孤子问相互作用的变化有望用于光开关器件。多个孤子作用结果对形成孤子阵列及阵列波导具有指导意义。 相似文献
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Detailed characteristics of the modulational instability (MI) oscillation in a single-mode optical fiber ring cavity are described. There is a clear threshold pump power for the oscillation, and stable oscillation can be achieved with proper synchronization. It is shown that phase coherence among pump, Stokes, and anti-Stokes consistent with the propagation of higher-order solitons plays an important role in the generation of MI gain. A noninstantaneous response of the nonlinear index (self-induced Raman gain) competes with the MI gain and produces an asymmetry in the spectrum of the Stokes and the anti-Stokes pulses. When a strong pump depletion occurs, the MI cannot be achieved, and the Stokes pulse forms unaided into a single soliton 相似文献
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Soliton transmission using periodic dispersion compensation 总被引:10,自引:0,他引:10
We examine the behavior of solitons in optical fibers where the dispersion is alternated between the normal and anomalous regimes. The periodic nature of the system strongly modifies the shape of the stable soliton (solitary wave) pulses, and increases their energy when compared with solitons in equivalent uniform fibers. Power enhancement factors of up to 70 are numerically observed. This leads to both an increased signal-to-noise ratio (SNR) at the receiver and reduced Gordon-Haus timing jitter. The interaction between pairs of isolated pulses is examined. We also examine implementations including periodic amplification, and show that the energy scalings introduced by the amplification and the dispersion management are independent provided that the periods of the two processes are dissimilar. We show that there is an optimum dispersion compensation ratio which minimizes the received Gordon-Haus jitter. A diagrammatic technique is presented for estimating the performance of dispersion compensated soliton transmission systems 相似文献
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Solitons, ultrastable light pulses that could revolutionize long-haul, fiber-optic communications and perhaps even optical switching, are discussed. Two classes of solitons are described. Temporal solitons, pulses of light that resist a medium's chromatic dispersion, or tendency to broaden them in time, have been known for a while. They offer the possibility of all-optical communication systems transmitting signals thousands of kilometers. Erbium-doped fiber amplifiers provide an all-optical form of soliton amplification that brings such lightwave systems closer to reality. Spatial solitons, which are actually light beams that travel through a planar waveguide without self-focusing or spreading, were observed for the first time last year and might eventually prove useful for optical switching 相似文献
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Alain BarthéLémy Bernard Colombeau Claude Froehly Laurent Lefort Stephane Ménard Michel vampouille 《电信纪事》1997,52(11-12):569-574
The basic principles of new ultrafast all-optical processing devices are experimentally demonstrated. One type of device relies on the interaction between an input signal and two colliding spatial solitons of a different wavelength in a planar waveguide with third order nonlinearity. The devices which belong to the second type are based on second order nonlinear interactions (degenerate difference frequency mixing) and operate as ultrafast sampling gate or as deflector or as phase conjugator. We report in a second part the design and performances of a laser that could be used to trigger the above mentionned systems. The laser cavity has two arms and two separate diode-pumped laser crystals (Nd/YAG). The two laser beams are coherently recombined inside the resonator into a single Gaussian beam. Picosecond pulses emission is ensured by passive mode-locking thanks to a nonlinear mirror set-up. 相似文献
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Singer A.C. Oppenheim A.V. Wornell G.W. 《Signal Processing, IEEE Transactions on》1999,47(10):2768-2782
Solitons are eigenfunction solutions to certain nonlinear wave equations that arise in a variety of natural and man-made systems. Their rich properties and tractability make them an intriguing component of such systems, often describing the large-scale or long-term behavior of natural systems, or the information content in certain communication or signal processing systems. However, it is often difficult to detect or estimate the parameters of solitons in such systems due to the presence of strong nonsoliton components or the nonlinear interaction of multiple solitons. The objective of this paper is to develop and investigate the detection and estimation of soliton signals. As a framework for this study, we consider using these nonlinear systems as both signal generators and signal processors in a form of multiplexed soliton communication. In contrast to more conventional uses of solitons in a communications context, our communication system uses soliton systems for signal generation and multiplexing for transmission over traditional linear channels. In addition to their mathematical tractability and the simplicity of the analog circuits used to generate and process them, we show that the soliton signal dynamics may also provide a mechanism for decreasing transmitted signal energy while enhancing signal detection and parameter estimation performance 相似文献