扩角镜的光学设计问题

文本用伽利略望远镜作扩角镜,给出一个1.67×扩角镜的设计实例,经加工测试证明,结果是满意的,有一定的实用价值.     

退耕还林(草)工程的现状与对策研究

本文对退耕还林(草)意义、目的、范围和必要性、可能性进行了论述，分析了退耕还林(草)过程中存在的问题，并提出了工程实施措施和机制创新．     

Er3+-Yb3+共掺磷酸盐玻璃放大器的大信号增益与量子效率理论分析

研究大信号工作状态下的Er^3 -Yb^3 共掺磷酸盐玻璃波导放大器的增益与量子转换效率。从量子转换效率的定义出发，得出了增益、抽运光功率以及量子转换效率三者之间关系的解析表达式。通过数值求解大信号工作状态下的Er^3 -Yb^3 共掺系统的速率方程与光功率传输方程，讨论了Er^3 浓度、Yb^3 浓度、Yb^3 与Er^3 浓度比率、抽运光功率以及放大器长度等因素对量子转换效率的影响。结果表明提高Er^3 浓度与增加放大器长度均有助于提高量子转换效率，高Er^3 浓度掺杂需要相应的高Yb^3 浓度与之相匹配以减小由于高浓度Er^3 掺杂引起的上转换效应，Yb^3 浓度的提高将降低器件的量子转换效率，Yb^3 -Er^3 浓度之比取1～2较好。     

高功率宽频带激光的高效谐波转换及其新进展

介绍了高功率宽带激光谐波转换的意义、理论处理和高效转换方式，在讨论和分析已有的光谱角色散和晶体级联方式的特点和局限性的基础上，提出可能的改善途径及其应用前景，并提出和研究了适用于小口径多路高功率激光系统的新型ＬＢＯ晶体方式。     

Modeling and experimental investigation of short pulse Raman microchip laser

The results of experimental and theoretical investigations of passive Q-switch Raman microchip lasers based on Nd³⁺:LSB active medium and Ba(NO₃)₂ Raman crystal are presented. It has been demonstrated that intracavity Raman conversion in the microchip lasers is a simple and efficient method, capable of delivering high power pulses with sub-100 ps duration. Intracavity generation of the 1st Stokes pulses with duration from 180 down to 48 ps and a peak power of 48 kW has been performed and studied. High peak power and short duration of the 1st Stokes pulses in microchip laser with Ba(NO₃)₂ Raman crystal allows to easily perform extracavity harmonic generation and frequency sum mixing in LBO, BBO, and KTP crystals with discrete-tunable wavelength from ∼1200 down to ∼240 nm. We have developed a generalized model of Q-switched Raman microchip lasers, that takes into account spatial inhomogeneity of pump, laser, and Stokes beams, thermalization within the upper and lower multiplets of activator ions in laser medium, and saturable absorber bleaching and recovery. For the microchip lasers with different saturable absorbers, the model achieves very good agreement with the presented experimental results in a wide range of pump powers.     

单片机波形发生器的设计

本文介绍一种利用８０３１单片机构成的波形发生器，对波形产生的原理、方法、频率控制及幅度控制进行了叙述，给出了详细的硬件原理图，主程序流程图及部分子程序流程图。     

A rigorous study of the rf fields in complex cavities with gradual transitions

Based on mode coupling theory, the general form of coupled second order differential equations for the longitudinal rf standing-wave amplitudes in a complex cavity with gradual transition is developed. The TM type non-principal modes generated due to mode conversion are systematically taken into account. Comparisions of numerical results including or excluding TM modes are made for several examples and some interesting results are obtained.     

Terahertz frequency conversion in bulk and quantum-well semiconductor lasers

Simulation results of frequency conversion up to the terahertz region in semiconductor laser devices, both in bulk and quantum-well structures, are presented with a comparison of traveling wave amplifiers and Fabry—Perot oscillators. In both devices conversion gains greater than 0 dB can be achieved with a proper parameter choice. Interesting features of the conversion gain spectra for the oscillator-converter are pointed out with a discussion of the performances.     

一种信息系统划分间的矩阵方法

本语文针对信息系统划分提出了一个新的属性归类的矩阵方法，使得繁琐的Ｕ／Ｃ阵分析统一在一种形式之一 属度概念构造了属性分类转换矩阵，通过转换矩阵直接得到各种划分结果并且给出了两种不同划分间的转换方法。     

在热压缩态中测量相位算符的涨落

利用热场动力学的方法计算了热压缩态中测量相位算符的涨落，引入了两种类型的基础量子涨落，一种是与测量相位的两个正交分量相联系，另一种是与一个测量相位分量和光子数相联系。由此，研究了热压缩压中测量相位涨落的两种压缩及其与温度的关系。