金属栅条掩埋型纳米光栅的设计与制备

An embedded wire-grid nanograting was designed and fabricated for using as a broadband polarizing beam splitter to reflect s-polarized light and transmit p-polarized light. A protected cladding layer of the same material as the grating＇s was deposited on the ridge, whereas the wire-grid is deposited in the grating trenches, which makes it more firm during application. High polarization extinction ratios of above 40 and 20 dB for transmission and reflection, respectively, with a broad wavelength range for the whole optical communication bandwidth （850 -1700 nm） and a wide angular tolerance （〉 ±20 °） are obtained by optimization of the designed structures, and the grating period is 200 nm.     

煤矿井下无源光网络的研究与应用

无源光网络(PON)在电信网中已得到广泛应用,但用于煤矿井下综合自动化网络平台则是刚刚起步.本文介绍了无源光网络的发展过程、EPON的工作原理、以及利用EPON技术构建的煤矿井下综合自动化传输平台的系统原理、系统结构、系统特点和主要技术指标.煤矿GEPON系统的建设为矿井各种子系统的建设接入提供了一个高速、安全、稳定的平台.该平台是矿井信息传输技术的一个突破,代表着国内领先水平.随着GEPON系统在煤炭系统的推广应用,其必将为我国煤矿安全生产提供更加可靠的保障.     

一种可调能量输出比光子晶体波导耦合分束器

在完整三角形光子晶体中引入3条相互平行的单模波导形成定向耦合型分束器,非对称地改变波导间耦合区的介质柱的折射率,可实现能量输出端口能量比的改变.时域有限差分数值仿真结果表明,耦合区介质柱折射率在改变量较小时,能保证分束器有较高的能量透过率,且能实现输出端口能量输出比在一定范围内的调节.     

Understanding the Meniscus‐Guided Coating Parameters in Organic Field‐Effect‐Transistor Fabrications

Meniscus‐guided coating (MGC) is mainly applicable on the soluble organic semiconductors with strong π–π overlap for achieving single‐crystalline organic thin films and high‐performance organic field‐effect‐transistors (OFETs). In this work, four elementary factors including shearing speed (v), solute concentration (c), deposition temperature (T), and solvent boiling point (T_b) are unified to analyze crystal growth behavior in the meniscus‐guided coating. By carefully varying and studying these four key factors, it is confirmed that v is the thickness regulation factor, while c is proportional to crystal growth rate. The MGC crystal growth rate is also correlated to latent heat (L) of solvents and deposition temperature in an Arrhenius form. The latent heat of solvents is proportional to T_b. The OFET channels grown by the optimized MGC parameters show uniform crystal morphology (Roughness R_q < 0.25 nm) with decent carrier mobilities (average µ = 5.88 cm² V^?1 s^?1 and highest µ = 7.68 cm² V^?1 s^?1). The studies provide a generalized formula to estimate the effects of these fabrication parameters, which can serve as crystal growth guidelines for the MGC approach. It is also an important cornerstone towards scaling up the OFETs for the sophisticated organic circuits or mass production.     

对称纤芯-包层光子晶体光纤的耦合特性

提出了一种新型对称纤芯-包层结构的光子晶体光纤,其截面由两组沿截面中心完全对称的纤芯-包层结构组成。对一组纤芯-包层结构的所有空气孔进行填充乙醇液体,利用填充液折射率的温度敏感性,来调制两纤芯之间的耦合特性。采用有限元法数值分析了该型光纤双芯不同结构参数及-20~70 ℃之间温度变化时的耦合特性。结果显示该型光纤双芯之间的耦合对温度具有高度敏感度,具有极短的耦合长度,在波长为1550 nm处耦合长度仅为55.00 μm,且可实现超短长度、高消光比偏振分束特性,长度为198 μm时消光比达到84.45 dB。该型光纤可以制作成性能很好的温度传感器和偏振分束器。     

大视场角1/4对称膜系偏光分束镜的研究

为了增大薄膜偏光分束镜(PBS)的视场角,从对称膜系等效折射率公式和截止带理论出发,设计了对称膜系结构的大视场角PBS。利用电子枪蒸镀法制备了低高低折射率(LHL)膜系结构的PBS,利用UV3101-PC分光光度计测量了PBS在不同入射角下的透射分光光谱,通过消光比测试系统测量了PBS反射光和透射光的消光比。结果表明,偏光分光光谱随入射角变化不明显,在视场角范围内具有较好的消光比(10-3量级),实验结果与理论设计一致。由此可见,利用周期性对称膜系设计大视场角薄膜PBS是完全可行的,为研制大视场角薄膜PBS提供了新的设计方法。     

Performance analysis of individual blade pitch control of offshore wind turbines on two floating platforms

Individual blade pitch state space (IBP SS) control and disturbance accommodating control (DAC) that reject wind speed perturbations are applied on a 5 MW wind turbine mounted on the barge and tension leg floating platforms for performance comparison in above rated wind speed region. The DAC used in this study is simply an IBP SS controller with a wind speed disturbance rejection component. For each controller implemented onshore and on the floating platforms, 60 10-min simulations with a variety of wind and wave conditions, where applicable, are carried out in accordance with the IEC-61400-3 standard design load case 1.2 for fatigue load testing. Results show that even with large tower load reductions by the IBP SS controller on the barge platform, these loads are still at least two and up to five times more than that for an onshore wind turbine. DAC on the barge platform has little impact on further improving the performance of the IBP SS controller. DAC on the tension leg platform manages to achieve loads comparable to that of the onshore system. Power and rotor speed regulation are improved and tower side-side load is reduced. Only the tower fore-aft load is 24% higher than the onshore wind turbine.     

一种新型的光束分束结构--复合调制型光栅

提出利用表面既有浮雕,体内又有折射率调制的一种新型衍射光栅来实现光束分束功能。针对波长为850nm正负一级和零级等衍射效率的光束分束器,优化设计了面型为正弦形、三角形、矩形的浮雕光栅以及体积相位全息光栅和复合调制型光栅共五种光栅。同时数值模拟了该光栅结构在实验制作过程中对各光栅参量误差的不敏感程度,该光栅在实验制作上优于其他类型光栅。     

冰洲石-玻璃组合三元结构平行分束偏光镜

为了既节省稀有昂贵的冰洲石晶体材料,又实现偏振光的大剪切差输出,采用冰洲石晶体与光学玻璃组合的方法,给出一种新型平行分束偏光镜的设计。该棱镜为ZBaF3玻璃中间夹冰洲石晶体薄片的三元结构,并由大折射率液态胶合剂溴代萘胶合而成。理论分析和实验测试表明,该棱镜消光比优于10-3,且可以实现大的横向剪切。     

与偏振无关1×2．2×2和2×4A由空间光开关在Clos光网络中的应用

首先,对无阻塞的Clos（2,4,2）光网络的拓扑结构和光学实现进行了理论分析;其次,利用偏振光分束器（PBS）、相位型空间光调制器（PSLM）和反射镜设计1×2、2×2和2X4光开关。进而设计无阻塞的Clos（2,4,2）光网络,并讨论了n×m型光开光的设计原则和升级能力。最后,通过实验测试,光开关的串扰最低可以达到...