基于自由空间耦合技术光开关的实验研究

本文提出了一种基于自由空间耦合技术的新型光开关器件.该光开关是利用聚合物薄膜的电光效应,通过控制导模的耦合效率来进一步控制反射光强来实现光的通断,理论与实验表明:该器件具有响应速度快、消光比大、损耗小、稳定性高,与传统棱镜耦合方式的光开关器件相比其具有结构和制备工艺更加简单和成本低廉等诸多优点.     

聚合物波导电光调制器阵列的研究及其应用

基于衰减全反射结构,提出了一种聚合物电光调制器阵列,该调制器含有多对电极,且多对电极可同时极化并可以独立工作.目前我们已在实验室成功制备了双通道聚合物波导电光调制器,并利用此调制器实现两路视频信号的同时调制.     

衰减全反射型聚合物波导光开关的实验研究

文章提出一种用衰减全反射(ATR)结构来控制光的开关效应的新型方法和装置.该光开关可利用聚合物薄膜的电光效应,通过电场控制衰减全反射结构中入射光能量到导模层的耦舍效率,实现光的开关效应.该器件具有功率损耗小、消光比大、响应速度快、稳定性好、制备工艺简单和成本低廉等诸多特点.     

聚合物偶极子天线型光纤电场传感器

设计并初步成功制作了聚合物光纤电场传感器.假设聚合物材料的电光系数r13=10 pm/V,设计的两种电场传感器的半波电场Eπ=36.2和15.8 kV/m.用自制的二阶非线性光学聚合物BPAN-NT作为聚合物光纤电场传感器的芯层材料,制作了电光调制器.用反应离子刻蚀的方法制作脊形光波导,通过电晕极化使芯层具有电光效应,...     

Optical Signal Processor Using Electro-Optic Polymer Waveguides

We have investigated an optical signal processor using electro-optic polymer waveguides operating at a wavelength of 1.55 $mu$m. Due to recent developments, many useful optical devices have become available such as optical filters, modulators, switches, and multiplexers. It will be useful to have a single optical device, which is reconfigurable to implement all of these functions. We call such a device an “optical signal processor,” which will play a similar role to digital signal processors in electrical circuits. We realize such an optical device in a planar lightwave circuit. Since the planar lightwave circuits are based on the multiple interference of coherent light and can be integrated with significant complexity, they have been implemented for various purposes of optical processing such as optical filters. However, their guiding waveguides are mostly passive, and the only viable mechanism to reconfigure their functions is thermal effects, which is slow and cannot be used for high-speed applications such as optical modulators or optical packet switches. On the other hand, electro-optic polymer has a very high electro-optic coefficient and a good velocity match between electrical and optical signals, thus, permitting the creation of high-speed optical devices with high efficiency. Therefore, we have implemented a planar lightwave circuit using the electro-optic polymer waveguides. As a result, the structure is complex enough to generate arbitrary functions and fast enough to obtain high data rates. Using the optical signal processor, we investigate interesting applications including arbitrary waveform generators.      

卫星地球站天线屏蔽方法研究

近年来,卫星地球站电磁环境日益恶化,必须加强卫星电磁干扰防护。天线作为卫星地球站最重要的设备之一,在完成正常收发任务的同时,也是电磁干扰耦合的主要途径。因此,对卫星地球站天线进行屏蔽是卫星地球站电磁干扰防护的一种行之有效的方式。根据刃峰绕射损耗模型,研究了地球站天线屏蔽体的设置方法,分析了屏蔽体设置距离与屏蔽体高度之间的关系。并根据理论分析结果,建议在地球站天线周围设置金属网。     

Surface-mountable EMC monopole chip antenna for WLAN operation

A novel surface-mountable monopole chip antenna having an electromagnetic compatibility (EMC) property is presented. In addition to the radiating strip on the chip base of the antenna, a ground portion is added on the side surfaces of the chip base. The antenna ground portion is to be grounded to the system ground plane of the mobile device for practical applications. The antenna ground portion can function as an effective shielding wall between the antenna and the nearby electronic components in the device. In this case, the nearby components can be placed in close proximity to the antenna, with small effects on the antenna performances. That is, the proposed antenna is EM compatible with the nearby components. In addition, the proposed antenna is surface-mountable onto the system circuit board of the mobile device, which reduces the packaging cost of the device. The proposed antenna applied to a smart phone or Personal Digital Assistant (PDA) phone for WLAN operation in the 2.4 GHz band is studied in the paper.     

高速聚合物电光调制器的进展

文中介绍了高速聚合物电光调制器的最新进展，包括电光调制器脊波导和微带线行波电极的设计、制作工艺及现在的最新产品和军事领域中的应用。     

Research on indoor electromagnetic radiation field of multiple antenna system

The complexity of the indoor environment brings great challenges to predict the electromagnetic radiation field of multiple antenna systems. Based on the Finite Difference Time Domain (FDTD) algorithm, using the mobile phone shielding device as the multiple antenna systems example, the mobile phone shielding device??s indoor electromagnetic radiation field is researched by measurment method and simulation method. The effectivity of prediction method is verified by comparing the prediciton results with the measurment results. About 80% of the error can be controlled less than 4 ± dB. The quantitative research has certain guiding significance to the prediction of the multiple antenna systems radio wave propagation.     

Design and Modeling of Traveling-Wave Electro-Optic Polymer Modulator for Ultrahigh Speed Applications

We present a complete model and design approach for high speed electro-optic (EO) polymer modulators. A general numerical model for arbitrary travelling-wave EO modulators is built, and the dispersion characteristic of each polymer layer in the device stack is carefully considered and integrated into the model. A velocity compensation layer is added to allow more room for increasing the waveguide core index to optimize half-wave voltage of the device. Microstrip mode analysis is also included to estimate the influence of different polymer stack to the E filed distribution inside the waveguide core. The device has been successfully designed and achieves more than 45 GHz EO bandwidth with a half-wave voltage of 3.2 V. A 100 Gbps EO modulator is under development.     

EAST 4.6 GHz多结波导阵天线电磁特性研究

多结波导阵天线是EAST超导托卡马克装置等离子体加热和电流驱动系统的关键部件,其结构性能直接关系到等离子体电流的加热效果和驱动效率。当等离子体电流破裂时,极短时间内的电流衰减将会在天线上引起感应电流,此电流与众多磁场作用产生电磁力和电磁扭矩,从而对天线结构造成损坏。该文研究了EAST装置等离子体电流破裂下4.6 GHz天线的电磁问题,采用有限元方法分析计算了天线的电磁力及力矩,并给出了不同电磁载荷条件下天线的电磁应力及形变。数值模拟的结果为低杂波天线的设计提供了重要指导。     

碳纤维天线表面金属化的研究及应用

介绍了碳纤维复合材料天线采用转移法进行表面金属化的技术。通过对高分子转移膜溶液配方、高分子转移膜制作和金属喷涂等进行研究,确定了碳纤维复合材料天线表面金属化的流程。在Ka频段对电磁波的反射特性进行测试,达到了设计指标要求。该方法操作简单,稳定性和可靠性较高,不影响制品精度,而且成本较低,适用于室温固化成型和中温固化成型,具有广泛的应用前景。     

战场光波段电磁环境分析

随着光电武器的不断应用,战场光电环境日益复杂,如何更好地适应和利用战场光电环境成为决定战争成败的关键.重点介绍了战场光波段电磁环境的含义,指出了光波段在整个电磁频谱中的重要地位,讨论了光信号在大气中的传输特性,分析了战场光信号环境的特性和构成,对战场主要辐射源的辐射特征进行了分析,并从频域和空域的角度对战场光波段环境展开了深入的讨论.     

蓝相液晶光电特性研究

蓝相液晶由于其特有的扭曲双螺旋结构,具有快速响应特性与宏观上的光学各向同性。通过聚合物稳定的方法,可以提升其热稳定性,但是也导致了驱动性能下降,磁滞效应增强等问题。文章通过研究手性掺杂和聚合物网络对蓝相液晶材料体系的作用以及不同温度下的磁滞效应,探索蓝相液晶器件光电特性的影响因子,为改善蓝相液晶材料的光电特性提供理论上的支持。     

An electromagnetic bandgap resonator antenna

This paper introduces a new explanation of the electromagnetic bandgap (EBG) material properties using the study of the EBG structures in the frequency domain and reciprocal space. Once the behavior of such a material is understood, the properties of the EBG are used in order to make an EBG antenna. The antenna is realized with dielectric EBG rods. Its directivity is increased compared to a simple patch antenna. Such a device allows us to obtain a high gain with a very thin structure.     

一种新型的聚合物网络胆甾液晶显示器

在胆甾液晶材料中掺入少量的聚丙烯类单体材料制作了一种新型的聚合物网络胆的液晶显示器。相对于传统的ＰＤＬＣ器件，这种新型显示器可以进行反模式显示，零电场时呈透明态，加电场呈散射态．而且还具有非常宽阔的视角特性。文中报道了器件的制作方法以及聚合物网络对器件电光特性的影响，并且对该器件的应用前景作了简要介绍。     

WLAN chip antenna mountable above the system ground plane of a mobile device

A novel wireless local-area network (WLAN) chip antenna suitable to be mounted above the system ground plane of a mobile device is presented. The antenna in the study is easily fabricated from folding a single metal plate onto a foam base, and mainly comprises a short-circuited radiating strip and an antenna ground. The antenna ground occupies the bottom surface and two adjacent side surfaces of the foam base. When the antenna is mounted at the corner of the system ground plane, this antenna ground structure is expected to effectively reduce the antenna's possible fringing electromagnetic fields inside the mobile device. In this case, when the associated element such as the radio-frequency shielding metal case is placed under the proposed antenna, small or negligible variations in the antenna performance are obtained. Design considerations of the proposed antenna for WLAN operation in the 2.4 GHz band are described, and results of the constructed prototypes are presented.     

Thermally poled PANDA fibre device with microstrip electrode

A novel thermally poled electro-optic PANDA fibre device is reported. The device was made from a piece of side-polished commercial PANDA fibre with a microstrip electrode deposited on the polished flat. The device demonstrated very stable performance with an electro-optic coefficient of ~0.4 pm/V     

Graphene Microstrip Patch Ultrawide Band Antennas for THz Communications

Future generation local communication systems will need to employ THz frequency bands capable of transferring sizable amounts of data. Current THz technology via electrical excitation is limited by the upper limits of device cutoff frequencies and by the lower limits of optical transitions in quantum confined structures. Current metallic THz antennas require high power to overcome scattering losses and tend to have low antenna efficiency. It is shown here via calculation and simulation that graphene can sustain electromagnetic propagation at THz frequencies via engineering the intra‐ and interband contributions to the dynamical conductivity to produce a variable surface impedance microstrip antenna with a several hundred GHz bandwidth. The optimization of a circular graphene microstrip patch antenna on silicon with an optimized return loss of ?26 dB, a ?10 dB bandwidth of 504 GHz, and an antenna efficiency of ?3.4 dB operating at a frequency of 2 THz is reported. An improved antenna efficiency of ?0.36 dB can be found at 3.5 THz but is accompanied by a lower bandwidth of about 200 GHz. Such large bandwidths and antenna efficiencies offer significant hope for graphene‐based flexible directional antennas that can be employed for future THz local device‐to‐device communications.     

Optimum design of a polymer electro-optic microring resonator switch

Novel transfer functions are presented for a polymer electro-optic microring resonator switches. The resonating process of the light in the microring is simulated using the formulas. Then the optimization of the structural parameters is performed, and the characteristics are analyzed, such as the resonance time, output spectrum, operation voltage, insertion loss and crosstalk were analyzed. The simulation results show that the designed device exhibits favorable switching functions.