Study of synchronously mode-locked and internally frequency-doubledcw dye laser

The analysis of the characteristics of a synchronously mode-locked and internally frequency-doubled dye laser is presented. Dependence of dye laser pulse characteristics on the cavity length mismatch of the pump laser and dye laser is studied. Variation of the minimum pulsewidth with intracavity bandwidth and the harmonic conversion efficiency is presented in the form of graphs.     

Three-phase-to-two-phase direct AC–AC converter with three leg structure

A three-phase-to-two-phase ac–ac converter is, along with a modulation strategy based on the space vector scheme, introduced to directly drive two-phase output ac systems with high input power quality. The converter is capable of synthesising two sinusoidal output voltages with variable output frequency and arbitrary magnitude in quadrature phase-shift as well as sinusoidal input currents.     

一种改进型免滤波D类音频放大器的设计

本文描述了一种基于华虹NEC0.35μmBCD工艺的改进型免滤波D类音频放大器。这种创新的结构基于归一化脉冲宽度调制技术,通过对回路滤波的输出信号进行合理的采样与保持,同时采用迟滞比较和反馈回路控制技术,很好地解决了传统脉宽调制方法中对于互调失真抑制能力较差的问题。     

Crosstalk pulsewidth calculation

Generally, it is better to use closed form expressions instead of simulation tools to predict coupling effects in a circuit and evaluate noise voltages characteristics. A new RLC crosstalk noise expression, based on an RLC transmission line model propagating each propagation mode, has recently been proposed and has been validated in previous works. From this expression, we propose in this paper to calculate the noise characteristics such as the maximum amplitude and the noise pulsewidth. They provide information on the way to modify the circuit structures or interconnect designs to reduce or control crosstalk noise more rapidly than by setting about electrical simulations.     

The influence of electron intervalley transfer on response pulse width of the MSM photodetector

This paper analyses the influence of nonstationary effects on response pulswidth of Metal-Semiconductor-Metal Photodetector (MSM-PD) made of a two-valley semiconductor. A phenomenological model is used for 2D numerical simulation of carrier transport and intervalley transfer. The analysis of the pulsewidth response of the MSM-PD has been made for various micron and submicron structures, bias voltages and incident light wavelengths.     

泵浦功率对同步泵浦激光器输出脉冲的影响

在理论和实验上研究了腔长固定情形下泵浦功率对同步泵浦激光器输出脉冲的影响。证明最佳锁模腔长与泵浦功率有关。     

固体脉冲激光器输出能量的普遍表达式

通过合理简化固体脉冲激光器的速率方程,得到了其输出能量的解析表达式。该表达式适用于光泵脉冲宽度与激活介质上能级寿命比值为值的情况。     

单池受激布里渊散射脉冲波形的研究

实验研究了单池系统的结构参数对受激布里渊散射（ＳＢＳ）脉冲波形的影响,通过改变透镜焦距、透镜与池的距离可以很容易地在１．５～８ ｎｓ之间调节ＳＢＳ脉冲宽度。利用含有受激布里渊散射噪声的理论模型对ＳＢＳ脉冲波形进行了数值模拟,理论与实验符合较好     

Cr4+:YAG被动调Q激光器脉冲波形数值模拟及优化

为了研究被动调Q激光器脉冲的波形对称特性,采用数值求解Nd:YAG晶体Cr4+:YAG被动调Q激光耦合速率方程组的方法,获得了激光脉冲的波形,绘制出了"脉冲对称因子"与饱和吸收体初始透过率和输出镜反射率的关系曲线图;并根据脉冲波形的不对称性,更精确地计算了脉冲宽度,及其与饱和吸收体初始透过率和输出镜反射率的关系.得到参数b=0.6时,脉冲波形对称;b=0.78时,脉宽最小的结论.结果表明,可以通过调整b参数来优化被动调Q脉冲波形对称性和脉宽.     

两类数字脉宽调制器工作原理之比较

当今脉宽调制技术在电火花微细加工所使用的脉冲电源中得到广泛应用。本文就硬件实现两类数字脉宽调制器的工作原理进行比较。作者经过实践证实了第二类脉宽调制器的可行性和优点。