k阶拟Bent函数在密码设计和通信中的应用

王育民、何大可提出了布尔函数关于线性函数的r阶相关度E(r)的概念来刻划布尔函数抵抗相关攻击的能力，本文以极小化所有非零相关度E(r)为主要目的，利用k阶拟Bent函数的特殊性质，给出了一类基于k阶拟Bent函数的“最佳”非线性组合设计的实现，构造了一类平衡的，具有高阶相关免疫性，而且非零相关度一致地小的非退化的布尔函数，并比较了它与基于部分Bent函数的“最佳”非线性组合设计的优劣。最后我们又利用k阶拟Bent函数构造了一类Bent互补函数族和Bent侣，Bent互补函数族和Bent侣在最佳信号设计方面意义重大，这也表明k阶拟Bent函数在密码设计和通信领域都有比较广的应用前景。     

Analysis of quantum noise in a singly resonant nondegenerate optical parametric oscillator

We have analyzed the evolution of quantum operators in a three-wave mixing process by using the nonlinear polarization driven wave equations and linearization of the quantum operators. We have theoretically shown that a nondegenerate optical parametric amplifier can generate amplitude-squeezed light when operated in the backconversion regime. Furthermore, a nondegenerate optical parametric oscillator, where only the signal wave is resonant, is proved to generate amplitude-squeezed light when the pump intensity is above the value at which 100% photon conversion efficiency is achieved. The calculated limit for amplitude-squeezing in this case is 3 d B.     

二次谐波产生的4．75μm激光

可重复生长的非线性红外晶体ＡｇＧａＧｅ２是Ｉ—ＩＩＩ－ＶＩ２簇化合物之一。具有对称的负单轴特性。使用光栅选频可调谐ＴＥＡＣＯ２激光器输出的９Ｐ（Ｘ）支线泵浦ＡｇＣａＳｅ２晶体可产生波长４．７５μｍ左右的激光。晶体长度为６．７ｍｍ，在１０．６１μｍ处按互关相位匹配加工。     

Investigation of nonlinear dynamics in CdS by time-resolved nondegenerate pump–probe system with phase object

The time-resolved nondegenerate pump–probe system with phase object is employed for investigation of nonlinear absorption and refraction dynamics in CdS. The 532?nm laser beam with 21?ps duration is used as the excitation and the laser beams of 600 and 680?nm with 10?ps duration from optical parametric generation are used for probing. The experimental results at both probe wavelengths show free-carrier absorption and large free-carrier refraction along with two-photon absorption and bound electronic optical Kerr effect. By numerically fitting the experimental data based on the nondegenerate pump–probe theory, the nondegenerate two-photon absorption coefficient, the nondegenerate Kerr coefficient, the free-carrier decay time, the free-carrier absorptive cross-section and free-carrier refractive coefficient at different wavelengths are all determined.     

原子间偶极相互作用对非简并双模T－C模型中原子布居及光场性质的影响

讨论了非简并双模光场与两个两能级原子相互作用的Ｔａｖｉｓ－Ｃｕｍｍｉｎｇｓ（Ｔ－Ｃ）模型中原子偶极－偶极耦合对辐射场的相关特性和原子布居的影响。     

利用多通道的光学超晶格产生对纠缠的连续变量频率梳

提出了一种实验上可行的,通过光学谐振腔内多通道参量下转换过程直接产生多色连续变量对纠缠频率梳的方案,腔内增益介质为周期极化的准相位匹配的钽酸锂(LiTaO3)一维光学超晶格.通过连续变量纠缠判据证明了每个通道中产生的每对参量光之间是相互纠缠的.讨论了对纠缠频率梳的纠缠特性随系统参数的变化.此方案在量子通信网络中有着一定的应用前景.     

TiO2半导体特性的转化与能带模型失效的理论研究

通过研究发现在某一特定温度附近时,TiO2 半导体特性明显发生改变,由非简并性半导体转化成为简并性半导体.采用自旋相关效应和库仑效应的理论,解释了能带模型失效的问题.     

Kerr效应对非简并双光子J—C模型中原子偶极压缩的影响

本文研究了一位于高ＱＫｅｒｒ介质腔中二能级原子与双模光场相互作用的系统中，Ｋｅｒｒ效应对原子偶极压缩和崩塌─回复效应的影响。结果表明，随着Ｋｅｒｒ效应的加强，原子偶极压缩程度减弱，以至消失，原子反转崩塌─回复效应的周期变短，振荡幅度减小．