单通激光片状放大器的模拟计算分析

介绍了高功率固体激光驱动器中单通片状放大器 (SSA)的模拟和实验研究结果。对放大器能量传输的各环节进行全系统模拟 ,在能源系统优化的前提下 ,对不同抽运条件和不同抽运腔构型放大器的增益特性进行实验研究 ,2 2kV工作电压下 ,获得了 4 9%cm-1的小信号增益系数和 2 4 3%的储能效率。同时还分析了放大器的抽运热畸变及波前变化 ,实验测量了由抽运引起的腔内洁净度变化情况。     

单口径片状放大器光束波前畸变热恢复研究

给出了在单口径片状放大器 (SSA)实验平台上利用哈特曼波前传感器进行热恢复研究的实验结果。结果表明 ,三片长的SSA双程最大热波前畸变约为 1 1λ峰谷 (P V)和 0 .13λ均方根梯度 (RMS) (λ =6 32 8nm)。实验结果与模拟计算结果进行了相互校核 ,两者符合得较好。     

片状放大器的应力应变

测量了片状放大器的应力、应变,改进了密封材料及安装方法,找到了一种不产生应力的密封方式.     

片状放大器归一化热参数研究

本文通过分析泵浦过程中，激光玻璃片内热量沉积的来源、建立了发热模型。通过数值模拟，研究了归一化热参数x与钕玻璃参数的关系，同时也讨论了其与泵浦脉宽的关系。     

两种新型泵浦腔结构片状激光放大器性能分析

介绍了两种新型闪光灯泵浦的不同泵浦腔构型片状激光放大器的结构组成，利用行波法对两种放大器的增益性能进行了实验测试，实验结果表明，采用模块化设计的阵列式片状放大器（MSA）比单口径片状放大器（SSA）具有更高的能量转换效率和增益能力。     

神光Ⅲ原型装置主放大器剩余热畸变模拟研究

给出了神光Ⅲ原型装置主放大器系统的热畸变模型 ,该模型包括三个模块 :热传输模块、热弹性力学模块、光学模块。利用该模型对原型装置的剩余热波前畸变进行了研究。初步结果表明 ,通过优化的冷却方案 ,可以在装置预定的运行周期内将激光工作介质内的温度梯度和总体平均温度冷却到可以接受的水平 ,剩余热波前畸变满足设计要求。利用该模型还定量地研究了增益介质的热膨胀系数与剩余热畸变之间的关系     

新型高功率固体激光阵列式片状放大器

4×2阵列式片状放大器系统是我国正在建造的大型激光驱动器装置的核心组成部分,将直接确定整个装置的能量转换效率和总体结构。放大器系统采用模块化方案设计可以有效提高装置的可维护性,减少运行维护时间,提高运行效率和装置的性价比。报道了一台通光口径为29cm×29cm的新型氙灯泵浦钕玻璃激光阵列式片状放大器模块的研制情况,介绍了放大器系统的结构组成,并给出了有关设计参数。     

延时水冷实现组合式钕玻璃片状放大器的主动热恢复

针对组合式片状放大器(MSA)只能进行被动热恢复的现状,研究了放大器中各关键单元器件的热恢复时序.结果表明,抽运结束后,钕玻璃和隔板玻璃之间的热传递存在交互变化的特点,在隔板玻璃升温之前采用主动冷却可消除钕玻璃主要热源.提出了采用延时全腔水冷的设计,从而在不影响放大器效率的基础上实现了主动热恢复,并就典型放大器给出了延时参数.     

神光Ⅱ高功率钕玻璃片状放大器接地实验研究

实验研究了高功率片状放大器不接地(悬浮状态)时感应电压的变化规律,结果表明:感应电压的大小主要受到金属腔体与氙灯之间的分布电容、放大器充电电压以及氙灯数量的影响;腔体之间不产生直接影响关系。实验研究了放大器在多种接地方式下的感应特性,提出了放大器内外腔电一体化并整体接地的接地方案,并将其成功应用到了神光Ⅱ第9路350mm片状放大器中,从根本上消除了放大器内部电击穿的可能性,并将放大器的感应电压降低到悬浮状态下的18%,提高了片状放大器运行可靠性和安全性,同时有助于改善放大器的紧凑性和洁净度。采用这种接地方案以来,350mm放大器可靠运行400多发次,未出现电击穿或干扰现象。     

大口径片状放大器增益均匀性实验研究

介绍了一台新型大口径片状放大器的实验研究以及放大器的结构组成。利用多束探针光系统测试了大口径片状放大器通光口径方向上的增益均匀性 ,不同抽运条件下的实验结果表明 ,在 2 2kV正常工作电压下 ,大口径片状放大器全口径的增益均匀性为 1 0 6∶1。     

片状放大器的静态波象差及对激光束方向性的影响

用三平板同轴全息干涉仪,研究了通光口径为φ100mm磷酸盐钕玻璃片状放大器的静态波差畸变;用CCD扫描测出再现焦点的尺寸,由此给出静态波象差对激光方向性影响的定量结果。     

Development of GaAs monolithic power amplifiers in X-band

The design, fabrication, and performance of several GaAs FET monolithic circuits are described. These include a two-stage, four-FET push-pull amplifier that has exhibited 1.4-W output power with 12.4-dB gain at 9.0 GHz, and a three-transistor monolithic paraphase amplifier (unbalanced input, balanced output) exhibiting 6-dB small-signal gain and a 1-dB gain compression point of 20 dBm. The amplifier chips utilize monolithically fabricated inductors, capacitors, and transmission lines to accomplish on-the-chip impedance matching.     

超分辨近场结构光盘的研究进展

超分辨近场结构(Super-RENS)光数据存储方案在近场超高密度光数据存储方面具有巨大的发展潜力和广阔的发展前景。在此方案中,超分辨结构的非线性层起着至关重要的作用。本文简述了Super-RENS光盘中两种类型光盘的结构及优点,并着重介绍了其工作机理的研究进展。     

Instrumentation amplifiers using operational transconductance amplifiers

Instrumentation amplifier circuits using operational transconductance amplifiers (OTAs) as active circuit elements are proposed in this paper. Two new instrumentation amplifier circuits have been described and experimentally verified, where the first circuit comprises four OTAs and five resistors and the second circuit comprises two OTAs and three resistors.     

Gated-diode amplifiers

This brief describes MOS amplifiers comprising a gated diode and a field-effect transistor. A gated diode is a two-terminal MOS device in which charge is stored when a voltage above the threshold voltage is applied between the gate and the source, and negligible charge is stored otherwise. The operation makes use of the nonlinear capacitance of the gated diode for voltage boosting, where voltage for 1-data is boosted high and voltage for 0-data stays low, achieving significant voltage gain, signal margin, and current drive. Further, a number of small-signal single-ended sense amplifier circuits are presented. The gated-diode sense amplifiers deliver high gain, require low power and low device count, and are tolerant to voltage and process variation.     

Signal-error-feedforward-controlled amplifiers

Signal-error feedforward can be used to control the performance of amplifier systems. Feedforward, unlike feedback, does not require signal loops, and therefore results in inherently stable systems. Some practical feedforward-amplifier configurations are given, followed by a numerical example that demonstrates the improvement obtained from the application of signal-error feedforward.     

Transmission-line amplifiers

A wideband thermionic vacuum-tube power amplifier in which an extended and continuous grid and cathode serve as an input transmission line that excites a corresponding traveling-wave signal on a similar transmission line between the screen grid and anode is analyzed. The usual gain-bandwidth product limitation is avoided by making the input and output capacitances part of the transmission lines. The gain mechanism is the same as that in the usual power tetrode in that bunched charges are delivered to the anode at the proper time and location along the anode transmission line to enhance the traveling-wave signal. If line attenuation losses are small, the power gain increases as the square of line length. Part of the backward wave can be made a forward wave by tapering the impedance of the output line. This type of amplifier could potentially use a field-emission cathode and thus avoid the high heater power and slow transit time of the thermionic emitter. Its disadvantages are low gain and low input impedance     

Simulating parametric amplifiers

In this paper, the problems of producing a general simulator model of a parametric amplifier are discussed. This model is to be simple, accurate, and applicable to many forms of parametric amplifiers. A brief discussion of the theory behind parametric amplification is followed by proposals for three models. Each of these is discussed in terms of its limitations and applications. The results of tests on two of these models are presented, and these results are discussed. Some emphasis is placed on the most sucessful of the models, which has been used to simulate a subharmonic oscillator.     

Monolithic millimetre-wave amplifiers

Ultra-wideband monolithic HEMT amplifiers have been designed and fabricated using MOCVD heterostructures. It has been shown that by taking into account the multiple reflections at the gate load, a very flat gain can be achieved and the sensitivity of the amplifier to the load resistances can be considerably reduced. By suitable design, the frequency bandwidth of the amplifier can be increased above the cutoff frequency of the active devices. In particular, it is shown that the cascode configuration reduces the coupling between gate and drain lines and increases the gain-bandwidth product, but can generate oscillations. To verify their design approach, the authors present the results obtained on 2-42 GHz monolithic amplifiers using 0.5 mu m HEMTs.<>