掺镱光纤放大器的啁啾脉冲失谐放大特性

 研究了掺镱光纤放大器对中心频率为1 053nm的啁啾脉冲放大特性，发现针对高斯或超高斯脉冲，采用合适的带宽及入射光强能够使增益饱和和失谐放大相互消弱，从而得到一个良好的放大脉冲形状。计算了掺镱光纤放大器失谐放大带来的相位调制，发现对压缩质量影响较小。     

双向抽运钛宝石啁啾脉冲激光多通放大的理论与实验研究

以双向抽运方式为基点，提出了新的、更接近实际的多通放大计算模型与方法，系统地计算分析了共焦腔双向抽运钛宝石激光放大器的放大特性，进而采用新的放大构型完成了啁啾脉冲多通放大．将实验结果与理论计算进行了比较，两者符合得很好．这种放大器大大减少了放大次数并彻底避免了再生腔必需的诸多光电元件 关键词：     

微电流放大器在物理实验中的应用

为用集成运算放大器LM324制作的微电流放大器电路图．集成运算放大器是一种高电压增益、高输入电阻和低输出电阻的多级直接耦合放大电路，它不仅能够放大交流信号，而且能够放大缓慢变化的信号或直流信号．图1中ICI(1／4LM324)为信号放大部分，采用差动输入，外部输出调零．     

钛宝石飞秒激光的啁啾脉冲再生放大

根据多通放大理论计算分析了再生放大器的激光放大特性，并采用啁啾脉冲放大技术完成了钛宝石飞秒脉冲激光的再生放大实验，获得了２ｍＪ的输出脉冲能量，增益大于１０６，对有关现象作了讨论。     

双向泵浦钛宝石脉冲激光的多通放大

 从基本理论出发，系统地计算分析了双向泵浦钛宝石激光放大器的增益特性，进而采用新的放大构型完成了啁啾脉冲八通放大实验，放大总增益近10⁶，输出脉冲能量达0.8mJ。     

用于飞秒脉冲放大器的马丁内兹展宽器与欧浮纳展宽器性能比较

用解析法针对多通和再生两种放大器，分别研究啁啾脉冲放大技术中马丁内兹展宽器和欧浮纳展宽器的特性和适用范围.我们认为在多通放大器和再生放大器中，马丁内兹展宽器均可以很好地补偿色散；如果使用再生放大器时需要将脉冲宽度展得更宽，可采用紧凑型欧浮纳展宽器. 关键词： 啁啾脉冲放大技术 马丁内兹展宽器 欧浮纳展宽器     

高功率激光放大器反激光能流分布的模拟

从Frantz-Nodvik模型出发,采用包含弛豫作用的速率方程组,将放大器对反激光的放大当作多程放大处理,模拟计算了光路中反激光的能流分布。光路为钕玻璃放大系统,激光脉宽1.0 ns,输出能量2.5kJ。放大器剩余增益的较大差异导致光路中各个元件反激光能流密度分布显著不同。与使用1级φ70 mm棒状放大器相比,采用2级φ70 mm棒状放大器时反激光能流相对集中,具有潜在的破坏危险。     

拉曼放大器中放大的自发拉曼散射与拉曼开-关增益关系的研究

研究了拉曼放大器中放大的自发拉曼散射对拉曼开－关增益的影响，并提出了一种利用自发拉曼散射谱来调整拉曼放大器位曼开－关增益平坦的方法，实验采用4个波长为14xx nm的激光二极管作为抽运源，75km的G．652光纤作为传输介质，获得了C波段附近的光放大，同时对此给出了合理的理论解释。     

基于光纤拉曼放大的级联式全光纤1020nm光源

设计并制作了输出功率为196 mW的级联式全光纤1020 nm光源.该光源采用光纤拉曼放大器与掺镜光纤放大器级联的放大方案,实现了对低功率1020 nm种子光的放大.在光纤拉曼放大级,采用了3段不同长度的拉曼增益光纤进行了对比实验,比较了一定信号光功率和抽运光功率下拉曼增益光纤长度对光纤拉曼放大级输出功率的影响;测量了...     

高功率掺镱双包层光纤放大器放大特性理论模拟

 运用掺镱双包层光纤放大器的理论模型，分析了连续和脉冲光放大时放大自发辐射(ASE)的计算方法。采用Runge-Kutta方法求解了考虑ASE稳态时掺镱双包层光纤放大器的放大特性，采用有限差分法求解了矩形、高斯和超高斯脉冲的放大特性。结果表明：用3 m长的双包层光纤、10 W的泵浦功率可以将脉宽3 ns、峰值功率为1 W的脉冲信号光峰值功率放大到15 kW左右；在饱和增益情况下，脉冲的波形变尖，宽度变窄；采用短的大模场双包层光纤和后向泵浦方式可以有效地降低ASE，并避免有害非线性效应。     

Design of broadband hybrid fiber amplifier based on particle swarm optimization algorithm北大核心CSCD

基于铒/镱共掺光纤放大器（erbium-ytterbium doped fiber amplifier, EYDFA）的理论模型和受激拉曼散射效应的分析理论,利用EYDFA和拉曼光纤放大器（Raman fiber amplifier, RFA）的增益谱互补特性,研究并设计了EYDFA与二阶多泵浦RFA相结合的混合放大器结构。为了得到高增益和低平坦度的混合放大器,引入了粒子群算法优化泵浦光波长和功率。仿真结果表明:在不使用增益均衡器的条件下,所设计的混合光纤放大器在输出端得到了近似相等的输出光功率,在90 nm的带宽范围内平均增益为38.78 dB,增益平坦度为1.1 dB,为混合放大器的设计和优化提供了参考。     

A High-Gain, 28GHz, 200kW Gyroklystron Amplifier

A design study of a high efficiency/gain gyroklystron amplifier is performed to demonstrate amplified radiation power of 200kW operating at 28GHz. A key design feature of the present gyroklystron amplifier is that the amplifier is designed to be high gain so that it can be saturated by a low power solid state power amplifier. A non-linear, time-dependent, large signal numerical code is used to predict tube performance. Simulations predict that a stable amplifier radiation power of 214kW is produced with a saturated gain of 54dB, an electronic efficiency of 37%, and a frequency bandwidth of 0.3% from a five-cavity gyroklystron amplifier. The amplifier gain is found to be very sensitive to a beam velocity spread.     

Multistage gain-flattened hybrid optical amplifier at reduced wavelength spacing

In this paper, two stage hybrid optical amplifier (HOA) composed of a single erbium doped fiber amplifier and Raman amplifier is proposed for dense wavelength division multiplexed (DWDM) system and investigate the impact of reduced channel spacing. The performance has been evaluated in the term of gain, gain flatness and noise figure. Also, using gain equalization technique, hybrid optical amplifier that has a gain flatness of 3 dB, and a noise figure of less than 7.4 dB is observed.     

Simulation and experimental characterization of Raman/EDFA hybrid amplifier with enhanced performance

We present simulation and experimental characterization of a hybrid amplifier comprising of a Raman amplifier and an erbium doped fiber (EDF) amplifier, with enhanced performance. The incorporation of a pumped EDF section in a fiber Raman amplifier (FRA) employing a dispersion compensating fiber is demonstrated to provide superior performance than a sole FRA system. The hybrid amplifier is characterized in terms of single channel gain and noise figure, and the results of measurements are shown to be in close agreement with the simulated results. Polarization-dependent gain (PDG) and multi-channel measured and simulated gain characterization of the Raman/EDFA hybrid amplifier are also presented.     

激光脉冲放大器的增益通量曲线研究

提出利用放大器的增益通量曲线来全面描述放大器增益特性的方法.并对单台放大器的增益 通量曲线进行了研究，从而进一步加深了对放大器的认识.为功率平衡研究提供有力工具. 关键词： 放大器 增益通量曲线 功率平衡     

一种增益平坦的光子晶体拉曼光纤放大器

为解决传统拉曼放大器增益系数低和增益不平坦的问题,采用级联光子晶体光纤的设计方法设计了一种增益平坦的拉曼光纤放大器.采用受激拉曼散射效应的稳态分析理论,分析了光子晶体光纤的拉曼增益谱,建立了拉曼放大器的理论模型.通过解耦合方程,推导了实现增益平坦的约束条件,发现光纤长度和泵浦功率是影响拉曼光纤放大器增益平坦度的两个参数.仿真结果表明,在1 508～1 544 nm的带宽范围内,实现了一个增益高达21 dB,增益平坦度仅为0.14 dB的光子晶体拉曼光纤放大器,可在光纤通信系统应用中发挥重要作用.     

Watt-level Er-doped and Er-Pr-codoped ZBLAN fiber amplifiers at the 2.7-2.8 microm wavelength range

Characteristics of diode-pumped Er-doped and Er-Pr-codoped ZBLAN fiber amplifiers were investigated at the 2.7-2.8 microm wavelength range. An amplified signal of 4.6 W was obtained from the singly Er-doped amplifier for an input signal of 110 mW, corresponding to a net gain of 16.2 dB. An amplified signal of 2.65 W was obtained from the Er-Pr-codoped amplifier for an input signal of 70 mW, corresponding to a net gain of 15.8 dB. It is found that the gain bandwidth of the singly Er-doped amplifier is much narrower than that of the Er-Pr-codoped amplifier. Small gain, no gain, or even a loss for shorter-wavelength signals propagating through the singly Er-doped amplifier should attribute for the large number residual populations in the lower laser level caused by the inefficient depopulation of the energy transfer upconversion processes.     

Optimum gain length for pulsed dye laser amplifiers

It is shown analytically that for a pulsed dye laser amplifier, transversely pumped by a short duration pulsed laser, there exists an optimum gain length of the amplifier at dye laser wavelengths at which ground state absorption does not vanish. Thus, if the available pump power is distributed over this gain length, the extraction efficiency and the saturated gain of the amplifier reaches a maximum. The dependence of the extraction efficiency and gain on the amplifier length is strongly affected by the nonlinear absorption of the dye laser arising from excited state absorption, subsequent to ground state absorption.     

Gain-clamped S-band discrete Raman amplifier

We demonstrate the advantages of an optically gain-clamped S-band discrete Raman amplifier: low gain variation over a large input dynamic range, effective suppression of Raman transients, and amplifier instability in the strong-pump-weak-signal configuration. We further investigate experimentally the operating conditions necessary for effective gain clamping and demonstrate gain flattening over 30 nm of bandwidth. Thus a gain-clamped discrete Raman amplifier shows promise for practical deployment.     

On the Similarity of the Statistical Characteristics of Spontaneous Radiation of a Quantum Amplifier at Different Gain Factors

The transformation laws governing the statistical properties of the quantum noise of an optical amplifier when its gain factor and spectral line profile are varied are considered. The correlation functions of quantum noise both at the amplifier output and after nonlinear transformation normalized to the correlation time of quantum noise at the amplifier output were found to be independent of the amplifier gain provided that it exceeds 10 for the Gaussian spectral line profile and 10³ for the Lorentzian profile. The spectral density of quantum noise transformed in a nonlinear system was shown to possess the same similarity property. It was found that the statistical characteristics possess a similarity property even in the case of variation of the spectral line profile from Gaussian to Lorentzian. It was concluded that such a characteristic of quantum noise of an optical amplifier as the correlation time bears virtually all information on the above-mentioned statistical properties at a reasonably large amplifier gain. The similarity property revealed has an important application. It allows finding the matching condition between the optical signal spectrum and the gain profile of the optical quantum amplifier to achieve the highest sensitivity of signal detection by the amplifier.