Tunable microlens arrays using polymer network liquid crystal

A tunable-focus microlens array based on polymer network liquid crystal (PNLC) is demonstrated. The PNLC was prepared using an ultraviolet (UV) light exposure through a patterned photomask. The photocurable monomer in each of the UV exposed spot forms an inhomogeneous centro-symmetrical polymer network which acts as a lens when a homogeneous electric field is applied to the cell. The focal length of the microlens arrays is tunable with the applied voltage.     

Remote Preparation of a Six-Particle Entangled Cluster-Type State

We consider the remote preparation of a six-particle cluster-type state using two four-particle GHZ states as the quantum channel in this paper. For the entangled six-particle cluster-type state with real coefficients, a deterministic remote state preparation scheme is proposed. It is shown that, conditioned on the outcome of Alice’s measurement, Bob can successfully prepare the target state by performing an appropriate unitary operation. With regard to the more general six-particle cluster-type state, we give another scheme which can successfully prepare the entangled state with probability 25%. And the probability of success can reach up to 50% or even 1 in some special cases. Furthermore, the classical communication costs in different cases are discussed.     

Synchronization of a network coupled with complex-variable chaotic systems

In this paper, synchronization of a network coupled with complex-variable chaotic systems is investigated. Adaptive feedback control and intermittent control schemes are adopted for achieving adaptive synchronization and exponential synchronization, respectively. Several synchronization criteria are established. In these schemes, the outer coupling matrix is not necessarily assumed to be symmetric or irreducible. Further, for a class of networks with an irreducible and balanced outer coupling matrix, a pinning control scheme is adopted for achieving synchronization. Numerical simulations are demonstrated to verify the effectiveness of the theoretical results.     

Piezoelectric properties of new ternary Bi1/2(Na, Li)1/2TiO3–(Bi1/2K1/2)TiO3–Ba0.85Ca0.15Ti0.90Zr0.10O3 ceramics

0.852[Bi_1/2(Na_1?x Li _x )_1/2]TiO₃?C0.110(Bi_1/2K_1/2)TiO₃?C0.038Ba_0.85Ca_0.15Ti_0.90Zr_0.10O₃ (BNLT?CBKT?CBCTZ-x) new ternary piezoelectric ceramics were fabricated by the conventional solid-state method, and their piezoelectric properties as a function of the Li content were mainly investigated. A?stable solid solution with a single perovskite structure has been formed, and the depolarization temperature (T _d) of these ceramics was identified by using the temperature dependence of the dielectric loss. The T _d value of these ceramics gradually decreases, while the T _m value increases with increasing the Li content. The dielectric constant increases and the dielectric loss decreases with increasing the Li content, and an enhanced piezoelectric behavior of d ₃₃??223 pC/N and k _p??35.2?% has been demonstrated in these ceramics with x=0.06.     

光学读出非制冷红外成像技术的光学灵敏度分析

不同于传统的非制冷红外成像技术,提出了基于微电子机械系统(MEMS)的新概念光学读出非制冷红外成像技术。它的光学读出系统基于空间刀口滤波原理,具有高灵敏度、高分辨率和高抗震性等优点,但同时也受到了反光板的弯曲变形、粗糙度等复杂因素的影响。在大量实验数据的基础上,利用夫琅禾费近场衍射理论,建立了复杂因素下光学灵敏度的理论分析模型,详细分析了刀口滤波位置、反光板的长度、曲率半径、粗糙度、LED光源的强度以及扩展宽度等对光学灵敏度的影响,并提出了通过极限操作使系统的光学灵敏度最大化的光学优化方法。     

基于裸光纤探头的双点光子多普勒测速系统

全光纤光子多普勒速度测量(PDV)系统是一种新型的激光测速系统,可广泛用于冲击波、爆轰波以及其他短时高速运动物体的速度测量。多点测量可以获得靶面不同位置的速度,以测量靶面的形变。为提高测量的空间分辨率,提出使用裸光纤束为PDV系统的探头,并在实验上实现了空间分辨率为375μm的双点速度测量。裸光纤探头的间距较小,一个探头的测量结果可能受到另一个探头反射光的干扰。理论和实验的研究结果表明,当靶面各点速度相同时,测量结果不受干扰光的影响;当各点速度不同时,其测速误差不但与两被测点的速度差有关,还与传感光和干扰光的光强和相位有关。     

Using Saganc loop of optical-injected semiconductor laser scheme for stable and continuous CW wavelength-tuning

We propose and experimentally investigate a stable and continuous wavelength-tuning laser structure by using self-injected Fabry-Perot laser diode (FP-LD) with Saganc loop scheme. In this proposed laser scheme, the lasing wavelength can be tuned in the range of 1526.20 to 1549.75 nm with tuning-step of 1.30 nm in single-longitudinal-mode (SLM) output. Here, the maximum and minimum output powers are −7.4 and −17.0 dBm, and their corresponding side-mode suppression ratios are 52.0 and 52.8 dB/0.05 nm, respectively. Moreover, to achieve the continuous wavelength tuning, we can also adjust the temperature of FP-LD for wavelength shifting.     

Quasi-elastic scattering of the proton drip line nucleus 17F on 12C at 60 MeV

The quasi-elastic scattering angular distribution of the proton drip line nucleus ¹⁷F on a ¹²C target was measured at 60 MeV. The experimental data have been compared with the theoretical analysis based onto optical model and continuum discretized coupled channels (CDCC). The couplings between breakup and elastic scattering channels, and between inelastic and elastic scattering channels resulted very weak. In order to explore the breakup effects the total reaction cross-section was deduced from the angular distribution of the quasi-elastic scattering data, and then compared with the existing data for the other weakly and tightly bound nuclei on ¹²C target using a universal function. From this comparison, we concluded that the breakup effect is not important for weakly bound projectiles on the light target as obtained also with the CDCC analysis.     

超导纳米线单光子探测器动态电感研究

单光子探测是一种量子极限光信号的检测技术,超导纳米线单光子探测器(Superconducting NanowireSingle-Photon Detector,SNSPD)作为一种新型的单光子探测技术,在量子通信等众多领域有着广阔的应用前景。SNSPD的动态电感直接决定了SNSPD的工作速度。文中对SNSPD动态电感的特性和测试方法做了详细的研究,成功实现了低温下SNSPD动态电感的测试,并对结果进行了分析处理和研究。利用BCS理论对动态电感随温度、偏置电流变化的特性进行分析计算,并与实际测量结果对比讨论,为未来如何降低SNSPD动态电感、提高其性能的研究工作提供了参考依据。     

Multiple magnetic transitions in single crystals of Ce<Subscript>12</Subscript>Fe<Subscript>57.5</Subscript>As<Subscript>41</Subscript> and La<Subscript>12</Subscript>Fe<Subscript>57.5</Subscript>As<Subscript>41</Subscript>

Measurements of magnetic and transport properties were performed on needle-shaped single crystals of Ce₁₂Fe_57.5As₄₁ and La₁₂Fe_57.5As₄₁. The availability of a complete set of data enabled a side-by-side comparison between these two rare earth compounds. Both compounds exhibited multiple magnetic orders within 2–300 K and metamagnetic transitions at various fields. Ferromagnetic transitions with Curie temperatures of 100 and 125 K were found for Ce₁₂Fe_57.5As₄₁ and La₁₂Fe_57.5As₄₁, respectively, followed by antiferromagnetic type spin reorientations near Curie temperatures. The magnetic properties underwent complex evolution in the magnetic field for both compounds. An antiferromagnetic phase transition at about 60 K and 0.2 T was observed merely for Ce₁₂Fe_57.5As₄₁. The field-induced magnetic phase transition occurred from antiferromagnetic to ferromagnetic structure. A strong magnetocrystalline anisotropy was evident from magnetization measurements of Ce₁₂Fe_57.5As₄₁. A temperature-field phase diagram was present for these two rare earth systems. In addition, a logarithmic temperature dependence of electrical resistivity was observed in the two compounds within a large temperature range of 150–300 K, which is rarely found in 3D-based compounds. It may be related to Kondo scattering described by independent localized Fe 3d moments interacting with conduction electrons.