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In this article, the effect of four-wave mixing (FWM) and amplified spontaneous emission (ASE) noise on WDM optical star networks has been investigated. Analysis for the evaluation of probability of error has been carried out (a) when only FWM is present and (b) when both FWM and ASE noise are present. Numerical results are presented in the graphical and tabular forms for the practical values of parameters. Finally, optimal location of the amplifier in the network has been identified as being before the star coupler preceding the receiver. 相似文献
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In this article, the effect of four-wave mixing (FWM) and amplified spontaneous emission (ASE) noise on WDM optical star networks has been investigated. Analysis for the evaluation of probability of error has been carried out (a) when only FWM is present and (b) when both FWM and ASE noise are present. Numerical results are presented in the graphical and tabular forms for the practical values of parameters. Finally, optimal location of the amplifier in the network has been identified as being before the star coupler preceding the receiver. 相似文献
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The impact of major fibre nonlinearities, like stimulated Raman scattering (SRS) and four wave mixing (FWM), in cascaded amplifier dense wavelength division multiplexing (DWDM) transmission system, has been studied at different data rates. SRS has been calculated considering pulse walk off effect. Analysis has been carried out to evaluate signal to noise ratio (SNR) considering the combined effect of SRS and FWM in the presence of amplified spontaneous emission (ASE) noise to achieve minimum noise at different data rates. 相似文献
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四波混频(FWM)效应是相干光正交频分复用(CO-OFDM)系统中最主要的非线性作用。分析基于小波变换的相干光正交频分(WT-OOFDM)系统原理,研究小波变换对FWM效应和光放大器自发辐射(ASE)引起的相位噪声的改善效果。数值结果表明,在采用常规G. 652光纤,100 Gbit/s的WT-OOFDM传输1500 km时,非线性相位噪声降低20%,总相位噪声降低15%。 相似文献
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In this paper, a novel method degrading the combined effect of four-wave mixing (FWM) and amplified spontaneous emission (ASE) noise of the amplifier on the most heavily affected channel in an equally channel spaced wavelength division multiplexing (WDM) system containing in-line optical amplifiers is proposed. FWM effect is directly related to input powers of channels. So, FWM effect can be degraded by controlling channel input powers. In the proposed method, varying the input power of each channel in an optical fiber, the output optical signal to noise ratio (OSNR) values are evaluated and input powers of all channels are optimized in order to maximize the OSNR value of the channel having the lowest OSNR. To interpret the results obtained, output OSNR values for the minimum optical input power launched to the system by each channel are also computed. Being compared to the computed results for minimum optical input powers, the lowest output OSNR value among all channels for optimized input powers shows a 5.1867 dB increase in a 5-channel system, a 3.5988 dB increase in a 9-channel system, a 3.0855 dB increase in a 15-channel system and a 1.6795 dB increase for a 21-channel system. Furthermore, output OSNR values of all channels exhibit a significant increase. 相似文献
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In this paper, a novel configuration of a wavelength converter is set forth by utilizing a semiconductor optical amplifier (SOA) as a nonlinear gain medium to generate a four-wave mixing (FWM) effect by using a dual wavelength bi-erbium-doped fiber laser that uses an Arrayed Waveguide Grating (AWG) together with two optical channel selector (OSC) as selective elements to function as a dual wavelength switchable pump power. The four-wave mixing (FWM) is produced with a wavelength detuning of 7 nm from the pump and signal which used is as the converted signal at wavelength 1532.8 nm or 1534.5 nm for transferring data from the input signal at wavelength 1547.0 nm. Thus, even though the conversion efficiency is as low as −43 dB, it is still possible for applications as a wavelength converter. 相似文献
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CHEN Jianxiao CHEN Zhangyuan TAO Zhenning WU Deming XU Anshi WANG Ziyu 《Chinese Journal of Lasers》2002,11(2):139-143
A novel scheme of all-optical wavelength converter(AOWC) based on dual pump four-wave mixing(DP-FWM) was demonstrated. To suppress the ASE noise of the semiconductor optical amplifier (SOA), one of the two pumps was generated interiorly from a loop laser constructed mainly by tunable optical filter and SOA. The theoretical model and some experimental results were presented. 相似文献
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A novel scheme of all-optical wavelength converter(AOWC) based on dual pump four-wave mixing(DP-FWM) was demonstrated. To suppress the ASE noise of the semiconductor optical amplifier (SOA), one of the two pumps was generated interiorly from a loop laser constructed mainly by tunable optical filter and SOA. The theoretical model and some experimental results were presented. 相似文献
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讨论了采用小信号分析法研究脉冲波在色散、非线性光纤中的传输时,放大的自发辐射(ASE)噪声作为功率调制项加入脉冲波的传输方程后所产生的效应.ASE噪声不仅被互相位调制不稳定增益所放大,还受二阶色散成分的影响.其传输函数为COS(1/2β2dzω2),这一函数不能通过色散补偿来消除,会削弱ASE噪声的影响.鉴于此,ASE... 相似文献
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Wei Chen 《Optics & Laser Technology》2011,43(7):1270-1273
Four-wave mixing (FWM) is a significant nonlinear effect in wavelength division multiplexing (WDM) fiber-optic systems. For two-wave transmission, it is easily found that the FWM noise power decreases with frequency spacing and increases with signal power. However, the variation of relative intensity noise (RIN) with frequency spacing and signal power is only 2 dB at most. The intensity fluctuations induced by the energy exchange between the FWM generated new waves and the original ones are trivial and the influence of FWM on RIN can be neglected. It is also found that the increase of RIN with signal power is mainly attributed to stimulated Brillouin scattering (SBS) rather than FWM. 相似文献
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Jing Huang 《Optik》2011,122(15):1376-1380
The small signal analysis method is presented for the discussion of amplified spontaneous emission (ASE) noise in dispersion and nonlinear transmission fibers in wavelength division multiplex (WDM) systems. Based on it, the complete ASE noise spectra (include the ASE noise, the ASE noise enhanced by parametric gain and the crosstalk caused by ASE noise and parametric gain) are described and the factors impacting on them are discussed. The crosstalk caused by ASE noise and parametric gain in single mode fibers, non-zero dispersion shift fibers and dispersion compensation fibers are analyzed. Taking into account the dispersion effect in the transmission fibers, the three types of ASE noise may decrease. 相似文献
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一种新颖的偏振不敏感的基于半导体光放大器的四波混频光波长转换方法 总被引:1,自引:0,他引:1
提出和论述了一种新颖的偏振不敏感的基于半导体光放大器的四波混频光波长转换方法。基本思想是设计和采用一种全光学偏振态转换器 ,理论上能将随机偏振态的输入信号光转换为固定偏振方向且功率基本不变的线偏振光 ,利用它控制信号光的偏振态能够克服四波混频过程所固有的偏振敏感性。将这种方法与正交偏振双抽运方法结合起来 ,能较简单地实现偏振不敏感且具有近似常数转换效率的宽带四波混频光波长转换 相似文献
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Noise in a coupling electromagnetic detecting system for high frequency gravitational waves 下载免费PDF全文
This paper discusses the basic categories of noise in detecting high
frequency gravitational waves in the microwave band (~0.1--10 GHz), which contain shot noise from the laser and the
thermal radiation photons, thermal noise from statistical
fluctuation of the thermal photons and fluctuation of the
temperature, radiation press noise on the fractal membrane, the
noise caused by the scattering of the Gaussian Beam (GB) in the
detecting tube and noise in the microwave radiometers. The analysis
shows that a reasonable signal-to-noise ratio may be achieved for a
detecting device with the fixed power of GB (105 W), only when
the temperature of the environment is no more than T=1 K, and the
optimal length of the microwave radiometers is about 0.3 m. 相似文献
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Supported by the Ministry of Posts Telecommunications the National Natural Science Foundation of China.QI Jiang CHI Nan ZHENG Yuan CHEN Shuqiang GUAN Kejian 《Chinese Journal of Lasers》2000,9(6):488-492
1 Introduction IntheWDMnetwork ,thedesirablefeaturesofanall opticalwavelengthconverterincludepolarizationinsensitivity ,transparencetomodulationformatandbit rate ,fulltunability ,acceptableoutputSNRovertheentirerangeofthewavelengthsusedinthenetwork[1] .Wave… 相似文献
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An analytical approach is presented to determine the performance of a tunable wavelength converter based on four wave mixing (FWM) in a single mode fiber (SMF) with two pump lasers. The analysis is carried out for an intensity modulated (IM) signal taking into considerations the effects of spectral broadening due to FWM and laser phase noise. The results evaluated at a bit rate of 10 Gb/s show that the signal power is substantially higher at lower values of wavelength separation. For example, for input powers of 10 mW each, wavelength separation of 4 nm between the pump-2 and the input signal, the output converted power is found to be –10 dBm corresponding to wavelength separation of 2 nm between pump-1 and converter signal. The corresponding crosstalk power is found to be –25 dBm at a channel separation of 3 times bit rate. 相似文献
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In WDM based fiber optic communication systems, nonlinearities deteriorate network performance. A channel wavelength assignment scheme is required which not only minimize the FWM effect but also the network delay produced during assignment process. Wavelength assignment schemes along with impairment constraint based routing (ICBR) is proposed which minimizes the effect of four wave mixing and network delay in WAN. Results have been obtained for 8 and 16 equally spaced channels and observed that for equally spaced channels, in comparison with adjacent-next channel assignment scheme the proposed channel assignment scheme gives improvement in the results in terms of lower power of FWM products and lower number of in-band FWM products. Unlike existing channel assignment schemes the algorithm is simple and there is no need to calculate the FWM effect for each channel before assigning it hence reduction in network delay. Calculations have been obtained for point to point multi-fiber link of 1000 km, when power launched per channel is 1 mW for amplified wavelength convertible WAN with amplifier placement of 50 km apart. 相似文献
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通过分析旋光纤喇曼放大器中信号光、抽运光的非线性薛定谔波动方程及放大自发辐射噪音特性,提出一种能同时在旋光纤喇曼放大器中产生预计波形放大自发辐射噪音,又方便计算的方法.根据放大自发辐射噪音时域特性,建立并在波动方程中加入放大自发辐射非高斯噪音模型.在考虑旋光纤双折射的非线性效应同时,通过分步傅里叶法对波动方程求解,计算了旋光纤喇曼放大器中的放大自发辐射噪音,并与实验结果吻合. 相似文献