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1.
本文对EDFA引入系统后产生的信号与ASE以及ASE之间的拍频噪声的电噪声功率谱进行了理论计算,通过实验进一步验证了EDFA的拍频噪声的特性。 相似文献
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分布式EDFA中受激布里渊散射效应的研究 总被引:3,自引:0,他引:3
利用含有受激布里渊散射效应(SBS)的传输方程,研究了透明传输和最佳掺杂浓度下,受激布里渊散射效应对分布式掺铒光纤放大器(d-EDFA)的各种特性的影响。结果表明:受激布里渊散射消耗了d-EDFA的泵功率,恶化了系统的噪声特性,使传输系统的最佳泵浦周期减小,所需的总泵浦功率增大 相似文献
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研制了用Nd-YLF激光器泵浦的掺Pr^3+氟化物光纤放大器(PDFA)组件,其最大信号增益和噪声指数分别是20dB和5dB。在输入信号功率11.0dBm时,得到19.2dBm的输出功率,试验结果证明:该PDFA组件用于副载波复用多信道AM-VSB视频信号传输时,具有低噪声特性。 相似文献
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介绍我们研制的多路FM-SCM(调频副载波复用)光波系统及其性能,讨论了SCM光波系统的噪声。该系统主要可用于多路CATV光纤传输。采用F-P腔LD和PIN-FET接收组件,通过系统优化,实现了接收端输出电视图象信号SNR〉55dB。 相似文献
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傅炜 《固体电子学研究与进展》1994,14(1):32-32
C波段16W内匹配GaAs功率MESFET傅炜(南京电子器件研究所,210016)1993年12月2日收到AC-Band16WInternallyMatchedPowerGaAsMESFET¥FuWei(NanjingElectronicDevice... 相似文献
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本文所建立的EDFA的理论模型考虑了ASE和光纤的本征衰耗,修改了速率方程和传输方程,对泵浦光功率,信号光功率沿光纤长度的分布及EDFA增益特性等进行了数值解,所得结果与实验结果符合较好。 相似文献
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《Microwave Theory and Techniques》1982,30(4):410-421
The noise characteristics in a Fabry-Perot (FP) cavity type semiconductor laser amplifier, biased at just below its oscillation thresh-old current, have been studied theoretically and experimentally. Quantum mechanical multimode rate equations containing a Langevin shot noise source and an input signal term were numerically solved for an exponential band-tail model with no k-selection rule. Noise power calculated using this rate equation was compared with a simpler photon statistic master equation method. The experimental results on noise power for an AlGaAs laser amplifier are in reasonable agreement with the two different theoretical predictions. Dominant noise powers in a semiconductor laser amplifier are beat noise powers between signal and spontaneous emission, and between spontaneous emission components. Noise characteristics in a Fabry-Perot cavity type laser amplifier can be improved both by the reduction of the facet mirror reflectivities and by use of an asymmetric cavity configuration with low-input and high-output mirror reflectivities. Two beat noise powers are expressed in simple analytic form by introducing an equivalent noise bandwidth and an excess noise coefficient as figures of merit in an optical amplifier. 相似文献
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Noise in an AlGaAs semiconductor laser amplifier 总被引:1,自引:0,他引:1
The noise characteristics in a Fabry-Perot (FP) cavity type semiconductor laser amplifier, biased at just below its oscillation threshold current, have been studied theoretically and experimentally. Quantum mechanical multimode rate equations containing a Langevin shot noise source and an input signal term were numerically solved for an exponential band-tail model with nok -selection rule. Noise power calculated using this rate equation was compared with a simpler photon statistic master equation method. The experimental results on noise power for an AlGaAs laser amplifier are in reasonable agreement with the two different theoretical predictions. Dominant noise powers in a semiconductor laser amplifier are beat noise powers between signal and spontaneous emission, and between spontaneous emission components. Noise characteristics in a Fabry-Perot cavity type laser amplifier can be improved both by the reduction of the facet mirror reflectivities and by use of an asymmetric cavity configuration with low-input and high-output mirror reflectivities. Two beat noise powers are expressed in simple analytic form by introducing an equivalent noise bandwidth and an excess noise coefficient as figures of merit in an optical amplifier. 相似文献
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Hamada M. Shimizu M. Okayasu M. Takeshita T. Horiguchi M. Tachikawa Y. Sugita E. 《Photonics Technology Letters, IEEE》1990,2(3):205-207
Measured noise characteristics of Er3+-doped optical fiber amplifiers pumped by 0.98- and 1.48-μm laser diodes (LDs) are reported. The noise figures estimated from the beat noise between signal and spontaneous emission are 3.2 dB for pumping by 0.98-μm LD and 4.1 dB for pumping by 1.48-μm LD. The beat noise between spontaneous emission components and the spontaneous shot noise for the 0.98-μm pumping are lower than those for the 1.48-μm pumping 相似文献
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《Optical Fiber Technology》1999,5(1):40-61
We integrate into a unifed model the fundamental conclusions of previous theoretical works concerning the quantum theory of linear optical amplifiers. We analyze the statistical processes contributing to noise in both laser and parametric amplification. We show that the so-called “signal/amplified spontaneous emission” beat noise directly originates from thermal statistics in stimulated emission, which causes unavoidable gain fluctuations. Such noise, which is in no way related to amplified spontaneous emission, is at the origin of the amplifier noise figure limit of 3 dB at high gains. The additional contribution of spontaneous emission noise (or more generally “amplified vacuum noise”), with one or two degrees of freedom (polarization), results in other “shot” and “beat” noise components, as discussed. This unified presentation thus provides an accurate and simple conceptual view of the different noise components in optical amplifiers. 相似文献
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In a BPSK optical homodyne receiver that utilizes a decision-driven phase-locked loop, the splitting ratio of the received power and that of the local oscillator power are very important parameters in achieving high receiver sensitivity. This paper determines the optimum setting of these parameters considering the influence of the relative intensity noise of the local oscillator and the thermal noise of the preamplifier. The optimum splitting ratio of the local oscillator power to the Q-arm is found to be 0.5. The splitting ratio of the received power to Q-arm is obtained as a function of laser linewidth. The optimum setting of the received power and the local oscillator power Is independent of the relative intensity noise of the local oscillator, the thermal noise of the preamplifier and the bit rate, At the optimum splitting ratios, required beat linewidth is obtained as 1.3×10 -3/Tb(τ/Tb≪1) and 2.99×10 -3/τ(τ/Tb≫1), where Tb is the bit duration and τ is the loop propagation delay time. We show that the total power penalty of 0.8 dB from the shot noise limit can be realized with the relative intensity noise of -170 dB/Hz and equivalent input noise current of 10 pA/√(Hz), even if an imperfect balanced receiver is utilized; quantum efficiency ratio of the twin-photodetector is 0.96, propagation time difference T/Tb is 0.01. To confirm the theoretical model, a BPSK homodyne detection experiment is performed and good agreement is found between theoretical and experimental results 相似文献
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HanWu Hu Hanan Anis 《Lightwave Technology, Journal of》2008,26(8):870-881
This paper presents a general formulation for the impact of back-reflection in wavelength division multiplexing-passive optical networks (WDM-PON) access networks. The analysis is applied to various wavelength-independent optical network unit (ONU) configurations such as amplified spontaneous emission (ASE)-locked Fabry-Perot (FP) lasers, reflective semiconductor optical amplifiers or injection locked FP using the downstream signal. The power penalty due to beat noise and its dependence on relative intensity noise, transmitter linewidth, and receiver bandwidth is investigated. The optimal gain at the ONU that minimizes the effect of beat noise is also found. The results show that the power penalty decreases as the linewidth of the the optical line terminal (OLT) and ONU light source increase. 相似文献
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论述了纳米电子器件与结构中散粒噪声的产生机理和影响因素,表明散粒噪声与输运过程密切相关,按照噪声功率谱的幅值大小将散粒噪声分为泊松散粒噪声、亚泊松散粒噪声和超泊松散粒噪声四类。将散粒噪声的这些规律应用于纳米电子器件和结构,可表征不同器件与结构中的量子效应。利用散粒噪声已经成功检测到无序导线中的开放通道与量子点混沌腔中的波动性,测量出超导体与分数量子霍尔效应中的准粒子电荷。将散粒噪声用于检测纠缠态对量子计算具有重要的意义,自旋相干输运的检测是自旋电子学的重要研究课题。 相似文献
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The assessment of the power penalty of optically preamplified receivers with signal-dependent noise (SDN) dominance is often accomplished by neglecting the influence of the optical filtering of the amplified spontaneous emission (ASE) noise on the signal-ASE beat noise. In this paper, it is shown that the optical filtering of the ASE noise can have a strong impact on the signal-ASE beat noise and remarkably affect the power penalty, even for optical filter bandwidths five times wider than the signal bandwidth. A simple expression to analytically evaluate the power penalty due to optical filtering, which describes reasonably well the influence of the optical filter on the signal-ASE beat noise variance, is proposed. The accuracy of the new expression is investigated, in the case of assessment of the optical filter detuning impact on receiver performance and the case of optical filter bandwidth optimization, and its predictions are satisfactory in comparison with rigorous estimates. Two new expressions of power penalty due to extinction ratio and to eye closure are also presented. It is shown that the power penalty due to eye closure depends on the extinction ratio and vice versa. Our results show also that the power penalty due to eye closure is remarkably dependent on the eye closure asymmetry 相似文献
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An optical RF feeding system for wireless access is proposed, in which the radio access points are distinguished by means of coherence multiplexing (CM). CM is a rather unknown and potentially inexpensive optical code division multiple access technique, which is particularly suitable for relatively short-range applications with moderate transmission bandwidth requirements. Subcarrier multiplexing (SCM) can possibly be used on top of CM, either as single-channel or multichannel SCM. The performances of the resulting distribution networks are analyzed, incorporating the effect of chromatic dispersion, optical beat noise, shot noise, thermal noise, and-in the case of multichannel SCM-intermodulation distortion. The results of the analyses are illustrated by using numerical examples, based on the IEEE 802.11b standard for wireless LAN. 相似文献
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利用锁相放大器,结合对Labview 软件编程,研究了电流调制激光引入的非稳散粒噪
声。通过对噪声功率谱的多次平均和快速傅立叶变换,有效地测量了非稳散粒噪声的频谱特性,研究结果表明非稳散粒噪声具有确定的相位依赖特性。 相似文献