两种多色相干光源的比较

从解析分析和数值模拟两个方面比较了两种多色相干光源的特性。结果表明：采用普通共振腔构型，由基模群聚产生的相干谐波与采用光速调管放大器构型，由外源预群聚产生的相干谐波比较，除了多一个基模输出功率以外，高次谐波输出功率至少同量级：而且前者不需要外源，只要研究对不同频率光的镜子反射系数和功率提取就可以了。     

单模光纤中皮秒啁啾脉冲压缩

对单模光纤正群速色散区秒啁啾脉冲的非线性传进行了近似的解析分析和定量的数值计算。结果表明，负啁啾脉冲在传输过程中能得到有效压缩。压缩比与脉冲初始峰值功率和初始啁啾程度有关。初始峰值功率一定的脉冲，其压缩比随初始啁啾程度的增大面大，初始啁啾程度一定的脉冲，压缩比随初始峰值功率的增大而减小，表明自相位调制效应导致脉冲压缩效果变差。计算结果还表明，在脉冲时域宽度得到压缩的同时，光谱宽度也能得到同步压缩。     

混凝土靶球形腔膨胀侵彻模型应用

Bishop等人于1945年开始用解析方法研究侵彻机理，导出了柱形腔和球形腔的准静态v膨胀方程，后来这种方法被称为空腔膨胀理论。目前，空腔膨胀理论已经在多种不同材料靶的侵彻研究中获得较为普遍的应用。Forrestal等人于1997年提出了一个适用于混凝土材料靶的球对称空腔膨胀侵彻模型，模型对靶结构的描述是将其压力与体积应变的关系理想化为不可压或线性可压，而将剪切强度与压力的关系理想化为由一拉伸阈值表示的Mohr-Coulomb准则。     

兰姆（Lamb，Willis Eugene，1913-）美国物理学家（Physicist，America）

波谱学是通过射频或微波电磁场与物质的共振相互作用研究物质性质和结构的学科。频率范围为10^4-10^12 Hz，测量以频率为主。由于射频和微波的能量子比可见光小得多，因而测量精度高，常用来测定原子的磁矩和电四极矩。分子束是高真空中定向运动的分子流，彼此间相互作用很小，因而可以看作孤立的原子和分子的结合，是研究原子和分子性质的有力工具。     

LD端抽运平直腔Nd:YVO4固态激光器的输出功率特性研究

对LD端抽运平直腔Nd:YVO₄固态激光器输出功率特性受激光器内在诸因素(热透镜效应、腔长、激活孔径等)的制约关系进行了研究.并用传播圆-变换圆图解分析方法给出了合理的解释，同时，对进一步提高其输出功率特性指出了方向. 关键词： 固体激光器 热透镜 变换圆 平直腔     

500.8 nmNd∶YAG青光激光器光学薄膜的设计与制备

从双波长激光运转及和频的机理出发，对LD泵浦Nd∶YAG，LBO腔内和频500.8 nm〖JP2〗青光激光器所使用的光学薄膜进行了设计和制备.在激光反射镜的设计上，为了达到最佳的和频输出，对膜系要求进行了深入分析.采用对谐振腔一端面反射率固定不变并通过对另一腔镜基频光的透射率进行调谐的方法, 在给出合理初始结构后，利用计算机对膜厚进行了优化.并采用双离子束溅射沉积的方法，通过时间监控膜厚法成功制备出青光激光器所使用的全介质激光反射膜, 在室温下实现946 nm和1064 nm双波长连续运转，并通过Ⅰ类临界相位匹配LBO晶体腔内和频在国内首次实现500.8 nm青色激光连续输出.当泵浦注入功率为1.4 W时和频青光最大输出达20 mW.     

Entangling Two Multi-atomic Clusters Through a Cavity Field

Two atomic clusters, which have NA and Ns two-level atoms, respectively, are placed in a cavity but separated spatially. There is no direct interaction between the atoms. All the atoms interact with a single-mode of the cavity field. Quantum entanglement between the two atomic clusters is investigated for various initial states of the two atomic clusters and the field. When the cavity field is initially in a Fock state, we find that the time evolution of entanglement quasi-periodically oscillates regardless of the initial states of atoms. The oscillation period increases as the initial photon number increases. When all the atoms in both of the atomic clusters are initially in the excited state, we show that there is no entanglement between the atomic clusters with NA = NB = 1 regardless the initial state of the cavity field. However, when either NA or NB is larger than one, we find that the entanglement always exists even for a strong thermal field. In cases with different initial states of the atomic clusters, we notice that the entanglement becomes stronger as number of the atoms increases. When all the atoms in both of the clusters in the ground state, we also find that the entanglement can be enhanced even by a thermal field. We also notice that a single qubit can be entangled with multi-atoms which are initially in the ground state by the cavity field initially being in vacuum, thermal, coherent, and squeezed states.     

变频率压缩态光场与原子的相互作用

研究了频率随时间变化的压缩态光场与二能级原子的相互作用，主要讨论了光场频率随时间作正弦调制和脉冲调制两种典型情况下，原子布居数反转随时间的演化特性。当光场频率随时间作正弦调制时，不仅光场频率调制，而且压缩态的压缩系数和压缩相位均对原子布居数反转的崩塌—回复过程有影响。当光场频率随时间作脉冲调制时，在原子布居数反转随时间演化过程中诱导出新的崩塌—回复过程，尤其在脉冲出现的区间内，原子布居数反转表现出持续的小幅快速振荡，这与压缩态的压缩系数无关。     

Realization of Greenberg-Horne-Zeilinger （GHZ） and W Entangled States with Multiple Superconducting Quantum-Interference Device Qubits in Cavity QED

An alternative scheme is proposed for generating the Greenberg-Horne-Zeilinger （GHZ） and W types of the entangled states with multiple superconducting quantum-interference device （SQUID） qubits in a single-mode microwave cavity field. In this scheme, there is no transfer of quantum information between the SQUIDs and the cavity, the cavity is always in the vacuum and thus the requirement on the quality of cavity is greatly loosened. In addition, during the process of the generation of the W entangled state, the present method does not involve a real excitation of intermediate levels. Thus, decoherence due to energy relaxation of intermediate levels is minimized.     

Auditory place theory and frequency difference limen

It has been a barrier that the place code is far too coarse a mechanism to account for the finest frequency difference limen for place theory of hearing since it was proposed in 19th century. A place correlation model, which takes the energy distribution of a pure tone in neighboring bands of auditory filters into full account, was presented in this paper. The model based on the place theory and some experimental results of the psychophysical tuning curves of hearing can explain the finest difference limen for frequency (about 0.02 or 0.3% at 1000 Hz) easily. Using a standard 1/3 octave filter bank of which the relationship between the frequency of a input pure tone apart from the centre frequency of K-th filter band, Δf, and the output intensity difference between K-th and (K l)-th filters,ΔE, was established in order to show the fine frequency detection ability of the filter bank. This model can also be used to abstract the fundamental frequency of speech and to measure the frequency of pure tone precisely.