用计算全息法检测卡塞格林系统主镜

为实现对卡塞格林光学系统中的非球面主镜表面面形的高精度检测,设计了一种二元位相型计算全息图(CGH)。介绍了工作原理,对CGH的相位模型参数的优化设计、衍射次级分离以及台阶位置与深度计算等关键问题进行了讨论。通过引入虚拟玻璃的概念快速建立非球面检测模型,针对卡塞格林系统主镜中心开孔的特点,通过加入同轴载波实现了衍射次级的完全分离,相比目前常用的倾斜载波方法简化了相位量化复杂度,数值仿真计算出了最优的台阶深度,降低了加工难度。给出了相应的设计方法及实例,研制投产了CGH。测试得到主镜面形的均方根误差为0.018λ,并与传统补偿器结果(RMS=0.019λ)进行对比,两者测试结果吻合,验证了该设计与检测方法的正确性,该设计方法简单快捷,适用于卡塞格林光学系统主镜面形检测。     

Continuous-Variable Entanglement Transfer from Cavity Field to Two Mesoscopic Josephson Junctions

We consider a composite system of two remote mesoscopic dosephson junctions interacting locally with a two-mode non-classical cavity field and investigate entanglement transfer from a bipartite continuous-variable （CV） system to a pair of localized mesoscopic dosephson junctions. We obtain analytically the time-dependent characteristic functions in the Wigner representation for the two CV subsystems, where two cases are considered for the zero and finite temperatures. Furthermore, we analyse the influences of the temperature on the period recovery of the entanglement.     

LaF3:Er,Yb纳米颗粒掺杂有机/无机杂化材料制备光波导放大器及特性研究

采用LaF3:Er,Yb纳米颗粒掺杂有机/无机杂化材料作为有源材料,制备了掩埋条形结构光波导放大器,研究了放大器在室温下的增益特性和波导中的频率上转换现象. 当抽运功率60 mW时,波导中明显可见绿色上转换发光,观测到Er3+从2H9/2,2H11/2,4S3/2,4F9/2到基态4I15/2跃迁分别对应的4个波长分别为405nm, 520nm, 544nm和650nm的发射峰,分析了其产生机理. 当输入信号光0.6mW,抽运功率160 mW时,在1535nm波长处获得1.5 dB/cm的相对增益.     

LaF3∶Er,Yb纳米颗粒掺杂有机/无机杂化材料制备光波导放大器及特性研究

采用LaF₃∶Er,Yb纳米颗粒掺杂有机/无机杂化材料作为有源材料,制备了掩埋条形结构光波导放大器,研究了放大器在室温下的增益特性和波导中的频率上转换现象. 当抽运功率60 mW时,波导中明显可见绿色上转换发光,观测到Er³⁺从²H_9/2,²H_11/2,⁴S_3/2,⁴F_9/2到基态⁴I_15/2跃迁分别对应的4个波长分别为405?nm, 520?nm, 544?nm和650?nm的发射峰,分析了其产生机理. 当输入信号光06?mW,抽运功率160 mW时,在1535?nm波长处获得15 dB/cm的相对增益. 关键词： 光波导放大器 增益 上转换     

Entanglement Transfer and Periodic Sudden Death Phenomenon in Two Parallel 1D Spin Chains of Quantum Spin Network

We investigate the entanglement transfer in two parallel ID spin chains of a quantum spin network, and show that the perfect entanglement transfer can be realized at some special times. In addition, the so-called ＇sudden death＇ phenomenon of entanglement is found in the spin network system.     

Effect of Phase Shift in Dual-Rail Perfect State Transfer

We investigate the effect of phase shift on the perfect state transfer through two parallel one-dimensional ring-shaped spin chains. We find that the total success probability can be significantly enhanced by phase shift control when the communication channel consists of two odd chains. The average time to gain unit success probability is discussed, showing that a proper phase shift can be used to enhance the efficiency of state transmission.     

Quantum Communication Through a Two-Dimensional Spin Network

We investigate the state or entanglement transfer through a two-dimensional spin network. We show that for state transfer, better fidelity can be gained along the diagonal direction but for entanglement transfer, when the initial entanglement is created along the boundary, the concurrence is more inclined to propagate along the boundary. This behavior is produced by quantum mechanical interference and the communication quality depends on the precise size of the network. For some number of sites, the fidelity in a two-dimensional channel is higher than one-dimensional case. This is an important result for realizing quantum communication through high dimension spin chain networks.