共查询到20条相似文献,搜索用时 31 毫秒
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Qian Yu Chongcheng Fan 《Lightwave Technology, Journal of》1997,15(3):444-451
Approximate analytical formulas for root mean square pulse width evolution in fiber systems using chained optical amplifiers are derived in this paper. Effects of group velocity dispersion (GVD) and self-phase modulation (SPM) are taken into account, and the system may have axially varying parameters, such as uneven fiber dispersion including dispersion management, nonequal amplifier spacing as well as output power, etc. It is shown that the analytical formulas can be applied to the design and analysis of a wide range of practical chained optical amplifier systems, and is helpful in the understanding of the pulse distortion caused by the interaction between SPM and GVD 相似文献
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从非线性薛定谔(NLS)方程出发,用数值方法研究了在自相似脉冲压缩技术中反常色散补偿光纤的群速度色散参量(GVD参量)和非线性参量对脉冲压缩效应的影响。结果表明,补偿光纤的GVD参量对压缩因子和脉冲峰值功率的影响是周期性的,随着GVD参量数值的增大,脉冲能量按集中-分散-集中的规律周期性变化,且变化周期逐渐增大,一周期内的能量转移加剧;每次能量集中时,脉宽接近压缩极限。最佳光纤长度随着GVD参量数值的增加而下降,但不受非线性参量的影响。另一方面,非线性参量的增大会降低压缩因子,不利于脉冲压缩。通过优化选择补偿光纤参数,能够接近脉宽压缩极限,提高脉冲压缩质量。 相似文献
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Time-resolved numerical analysis of a nonlinear Sagnac interferometer switch (NSIS) reveals that the combined effects of group velocity dispersion (GVD), self phase modulation, cross phase modulation, and pump-probe walk-off seriously degrade switching performance when the soliton number N of the pump pulse is under 5. This means that the peak power of short pump pulses cannot be reduced to less than the critical value at N >5 to prevent the effect of GVD. This restriction is more severe for pump pulses in the anomalous dispersion region than for those in the normal dispersion region because of higher-order soliton compression. System designs for time-division demultiplexers that use NSISs and picosecond pump pulses generated by a laser-diode coupled to erbium-doped fiber amplifiers are discussed. It is found that 1:32 demultiplexing from 160 to 5 Gb/s and 1:8 demultiplexing from 80 to 10 Gb/s with a switching contrast of more than 60 are possible using diode-laser-pumped 1- and 2-ps pump pulses, respectively 相似文献
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S. Tsukamoto K. Katoh K. Kikuchi 《Photonics Technology Letters, IEEE》2006,18(9):1016-1018
We demonstrate unrepeated optical transmission of 20-Gb/s quadrature phase-shift-keying (QPSK) signals over a 200-km-long standard single-mode fiber (SMF) without using any optical dispersion compensator. By employing optical homodyne detection, which can restore the entire information of the complex amplitude of the transmitted signal, group-velocity dispersion (GVD) of the SMF can be compensated electrically by a linear equalizer at the receiver. From off-line bit-error-rate measurements, we find that a simple transversal filter implemented in digital signal processing circuits after homodyne detection can effectively cancel the fiber GVD of up to 4000 ps/nm, enabling successful 20-Gb/s QPSK transmission. 相似文献
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Arahira S. Kutsuzawa S. Matsui Y. Kunimatsu D. Ogawa Y. 《Lightwave Technology, Journal of》1998,16(3):405-410
In this paper, we describe a novel method for generating a highly repetitive optical pulse train using mode-locked pulses and the group-velocity dispersion (GVD) of optical fiber. An optical pulse train at a multiplied repetition frequency oscillation of an initial mode-locked pulse train is obtained by adjusting waveform fiber length in accordance with the mode-locking frequency and the fiber's GVD. A subterahertz optical pulse train (98-196 GHz) was successfully generated with low pulse intensity fluctuation 相似文献
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In this paper, an optically controlled tunable delay scheme has been proposed using four-wave mixing (FWM) wavelength conversion in a 35-cm highly nonlinear bismuth-oxide fiber (Bi-NLF) together with group velocity dispersion (GVD) in a chirped fiber Bragg grating (CFBG). The Bi-NLF offers a very large nonlinearity and gives rise to significant FWM over a short fiber segment. With the use of a CFBG, a delay range over 185 ps has been experimentally demonstrated. To investigate the performance of the tunable delay, we have applied the scheme for variable delays of 10-Gb/s amplitude-shift keying (ASK) and differential phase-shift keying (DPSK) data signals. The bit error rate (BER) measurements show a power penalty of less than 3.5 dB for both amplitude- and phase-modulated data formats. To further increase the delay time, the CFBG has been replaced by a dispersion compensated fiber (DCF) that provides a wider bandwidth of operation. A variable delay up to 840 ps has been obtained using dual-pump FWM that offers a conversion bandwidth of about 40 nm. The large conversion range helps to minimize GVD-induced pulse distortion as a shorter DCF can be used for a given delay. The Bi-NLF provides an enhanced stimulated Brillouin scattering (SBS) threshold, a reduced latency, and an increased compactness of the approach for practical applications. 相似文献
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设计了一种采用半导体可饱和吸收镜(SESAM)实现被动锁模的激光器,该激光器中只有单根的全固型掺镱光子带隙光纤(AS-Yb-PBGF).在1μm波段,该光纤具有负的群速度色散(GVD),因此腔内激光增益和负的GVD同时由该光纤提供.激光腔内非线性效应与仅由AS-Yb-PBGF提供的负GVD平衡作用可使激光器实现孤子运转.用分步傅里叶方法数值模拟了其孤子运转的动力学过程,该系统中初始的噪声信号经过数百次循环就可以得到稳定的孤子运转.输出脉冲能量为135 pJ,脉冲宽度为125 fs,时间带宽乘积为0.33,接近傅里叶变换极限的脉冲,脉冲重复频率可达500 MHz.系统地研究了整个激光器中孤子脉冲演变的动力学过程. 相似文献
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群速度色散和高阶非线性效应是影响超强超短脉冲抽运下光参变放大能量转换效率的重要因素.为了提高光参变放大的能量转换效率,采用理论分析和数值计算的方法,模拟超强超短激光脉冲抽运下MgO:LiNbO3晶体中的光参变放大过程,得到了不同抽运功率密度、不同群速度色散条件下光参变放大的能量转换效率曲线,并且讨论了高阶非线性效应对和脉冲时间波形和频谱的影响.结果表明,群速度色散会使抽运光脉宽增加,功率密度降低;大功率密度抽运下高阶非线性效应的影响不可忽略,它会进一步减小能量转换效率,还会使信号光的频谱展宽,为了提高单位晶体长度的参变放大增益,可以通过引入初始啁啾来抵消群速度色散的影响. 相似文献
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Highly nonlinear bismuth-oxide fiber for supercontinuum generation and femtosecond pulse compression 总被引:1,自引:0,他引:1
Gopinath J.T. Shen H.M. Sotobayashi H. Ippen E.P. Hasegawa T. Nagashima T. Sugimoto N. 《Lightwave Technology, Journal of》2005,23(11):3591-3596
Highly nonlinear normally dispersive bismuth-oxide fiber shows promise for applications such as supercontinuum generation and femtosecond pulse compression in the telecommunications-wavelength range. To generate a wideband and flat supercontinuum spectrum, the balance between fiber nonlinearity and normal group velocity dispersion (GVD) is important. Highly nonlinear bismuth-oxide fiber exhibits a large nonlinearity due to the small effective area and nonlinear index of the host glass material. The fiber also has a relatively flat dispersion profile over a large wavelength range. Utilizing these features, we generate a smooth unstructured supercontinuum between 1200 and 1800 nm. This supercontinuum is passed through a grating pair, and pulses, originally of 150-fs length, are compressed to 25 fs. 相似文献
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为了探讨超短光脉冲在分布式光纤放大器中的传输放大特性及影响因素,建立了光脉冲在光纤放大器中的基本传输方程,以掺镱光纤放大器为例,采用分步傅里叶变换法对放大器中光脉冲的演变进行了模拟,讨论了初始啁啾和增益色散的影响。结果表明,当光脉冲在分布式光纤放大器中传输时,光纤的色散、非线性效应均会影响脉冲的形状和频谱,光脉冲初始啁啾也会对脉冲的传输状态产生影响;对于宽频谱光脉冲,增益色散相当于一种损耗机制,应该考虑其影响。相关结果对光纤放大器的系统设计和优化具有一定的参考价值。 相似文献
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The Transmission Performance of Non-zero Dispersion Shifted Fiber Communication Systems Using In-line Phase-sensitive Amplifiers 总被引:2,自引:0,他引:2
1 IntroductionHigh speedlong distance (non regenerative)transmissionisthemaingoalofopticalfibercommu nications.Thefactorslimitingtransmissionspeedanddistancearefiberloss,Group velocityDisper sion (GVD )andfibernonlinearity .IthasbeenshownthatErbium dopedFiber… 相似文献
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A single-mode optical fiber with a convex chromatic dispersion profile is proposed for generating a flat supercontinuum(SC).The fiber has normal dispersion and the dispersion parameter D(λ,z) is a convex function of wavelengths.It is shown from the numerical results that the chromatic dispersion,the flatness of the dispersion curve and the pump conditions have significant effect on SC generation.A flat and broad SC without strong residual pump component can be obtained when the pump wavelength is set in the... 相似文献
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采用掺铒光纤放大器(EDFA)和高非线性色散位移光纤(HNL—DSF)组成非线性放大环镜(NALM),利用掺铒光纤放大器的高增益系数和高非线性色散位移光纤的光学克尔效应构造全光开关,实现脉冲整形和消除干扰噪声。采用分布傅里叶法分析了高非线性色散位移光纤的群速度色散(GVD)对非线性放大环镜开关特性的影响,讨论了掺铒光纤放大器的增益系数、增益饱和特性以及耦合器的耦合比等因素的影响,研究了入射光为高斯脉冲的情况下,非线性放大环镜与入射光信号强度相关的放大滤波特性。通过优化非线性放大环镜的各项参数,可以在实现高开关效率的同时,降低对开关功率的要求,对峰值功率低于1mW的超短脉冲进行Tbit/s量级的开关操作,从而适用于超高速大容量光通信系统中。 相似文献
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Arahira S. Kutsuzawa S. Matsui Y. Kunimatsu D. Ogawa Y. 《Photonics Technology Letters, IEEE》1998,10(2):209-211
We describe the generation of a synchronized, low-jitter, subterahertz optical pulse train by repetition-frequency multiplication of a subharmonic synchronous mode-locked semiconductor laser diode using the group-velocity dispersion (GVD) of optical fiber. A 49-196 GHz optical pulse train was generated with low intensity fluctuation and with low timing jitter, by adjusting fiber length in accordance with the mode-locking frequency and the fiber's GVD 相似文献