多功能光环行器结构与特性分析

在环形器设计中引入双尾纤和透镜对,使光环形器中器件功能复用,成功设计了一种具有功能复用的新型双通道多功能光环行器。利用琼斯矩阵对其进行了传输特性理论分析。分析表明,该器件具有与单尾纤光环行器相同的低插入损耗(IL)、零偏振模式色散(PMD)和高隔离度(IS)等特性。     

1 053 nm波长光环行器的研制

利用高斯光束传输理论与晶体偏振光学理论设计了1 053 nm波长光环行器,并应用先进的金属化焊接封装工艺制作了该器件.该器件的插入损耗小于1.8 dB,隔离度大于30 dB,达到了预先设计的目标.     

Q波段双通道幅度控制多功能芯片

设计了一款Q波段的双通道多功能单片电路,其内部集成了威尔金森功分器、六位0.5 dB步进数控衰减器和单刀双掷开关。在设计过程中,开关单元电路采用三级并联结构,有效降低电路插入损耗,提高隔离度;数控衰减器单元采用多节并联T型结构,改善高频段插入损耗和衰减精确度指标。通过以上设计方法,该单片电路在40~50 GHz插入损耗为10 dB,隔离度为26 dB;能够实现幅度控制步进0.5 dB,最大衰减量31.5 dB。     

低插入损耗高隔离度SOI射频开关电路的研究

基于0.18μm RF SOI CMOS工艺,提出了一种可广泛应用于无线通信系统中的低插入损耗高隔离度SOI射频开关电路.该电路利用SOI器件的特殊结构(隐埋氧化层BOX,高阻衬底)和特殊SOI器件(FB,BC,BT等),使电路采用的器件较之体硅CMOS器件具有更优的隔离性能,实现了降低插入损耗和增加隔离度的目的.该电路经过模拟仿真,在频率为2.4 GHz时,插入损耗和隔离度分别为-1 dB和40 dB.     

一种具有监视功能的两级反射式光隔离器

提出了一种具有监视功能的两级反射式光隔离器,给出了设计思想和工作原理,利用矩阵光学理论对器件的隔离度和插入损耗进行了理论分析,给出了制造误差与隔离度和插入损耗之间的关系.     

误差自愈型高隔离度准四端口光环形器的研究与设计

针对现有光环行器内部元件之间存在的角度误差、各种同类异构光环行器不能消除半波片光轴取向误差所导致的隔离度降低、隔离度不一致以及安装调试繁琐等弊端,提出了一种减小或消除误差的双半波片光轴非对称结构方式,设计了一种误差自愈型高隔离度准四端口光环行器,通过理论分析、琼斯矩阵运算和数学软件MATLAB模拟,其插入损耗可达到已有光环行器最小性能指标,而隔离度可以提高5～8 dB.     

高隔离度偏振无关光环行器

本文报道了一种高隔离度偏振无关的三端口光环行器。该环行器在１．５５μｍ中心波长±２０ｎｍ范围内，插入损耗低于１ｄＢ，隔离度大于４５ｄＢ，偏振相关损耗低于０．２ｄＢ，串音大于５０ｄＢ，回波损耗大于５０ｄＢ。     

无磁性光子晶体类T型非互易性双通道滤波器设计

基于无磁性二维光子晶体设计了一种由直线波导及矩形谐振腔构成的类T型非互易性双通道滤波器。矩形谐振腔具有局域多频率电磁波且电磁波传播方向可调的特性，直线波导的结构尺寸决定了其对不同对称性电磁波的承载能力。利用矩形谐振腔和直线波导的特性实现了非互易性双通道滤波功能。实验结果表明：正向传输情况下，滤波器实现了中心波长分别为1534 nm和1574 nm，带宽分别为16 nm和8 nm的滤波传输，对应的插入损耗分别为0.4 dB和0.36 dB，通道间隔离度为33 dB和22 dB；反向输入情况下，电磁波对称模式的不匹配导致无法传输。这表明设计的双通道非互易滤波器滤波效果良好，在未来全光通信集成领域具有潜在的应用价值。     

基于M型六角铁氧体Ba(ZnHf)0.08Fe11.92O19的自偏置微带环行器设计

电子信息技术的发展对环行器提出了低损耗、高隔离度及小型化的要求，采用具有高剩磁比(M_r/M_s)和强各向异性场(H_a)的BaM自偏置铁氧体材料有利于提高环行器性能和减小器件尺寸。在阐述高度取向M型六角铁氧体Ba(ZnHf)_0.08Fe_11.92O₁₉制备工艺的基础上，表征了材料的相结构、微观形貌和磁性能。根据环行器设计理论，基于0.25 mm厚度的BaM铁氧体材料仿真设计了工作于Ku波段的双Y结和开槽多Y结环行器。仿真结果表明，两种环行器均在12.44 GHz处显示出良好的环行功能，电压驻波比均小于1.22。在中心频率附近，双Y结环行器插入损耗为0.61 dB,相应的隔离度为26 dB,20 dB带宽为1.3 GHz;开槽多Y结环行器插入损耗为0.505 dB,相应的隔离度为36 dB,20 dB带宽为1.03 GHz。相比于双Y结环行器，开槽多Y结环行器在保证器件性能的前提下，能够有效改善插入损耗和隔离度等性能，并有利于减小环行器尺寸。     

S波段双通道高功率波导旋转关节的研制

介绍了一种S波段双通道高功率波导旋转关节,对旋转关节的结构组成、关键尺寸选择、模式匹配及通道间隔离设计等进行了详细的分析和研究.仿真分析和测试结果表明,在10%的带宽内,旋转关节电压驻波比小于1.1,驻波转动起伏小于0.02;插入损耗小于0.2dB,插入损耗转动起伏小于0.02dB,通道间隔离度大于85dB,双通道功率容量均超过1MW.通过对比,旋转关节各项性能指标均达到国外同类产品的先进水平,同时结构形式简单,加工调试方便,可广泛应用于雷达及微波系统中.     

Excess Loss of the Coupling System to Double-Function Optical Circulators Utilizing Lens Twice and Two-Fiber Tips

1 Introduction An optical circulatoris useful in advanced optical fibercommunication systems such as full duplex transmissionsystems[1 ~10]. With the development of fiber opticalcommunication,there is anincreasing demand for opti-cal circulators that are suitable for use with fiber opticsystems .Incomplexfiber optic systems ,there may be amultiplicity of fibers ,each requiring a si milar function.A conventional optical circulator cannot provide suchfunctions[11]. In addition,the circulator re…     

Waveguide polarization-independent optical circulator

We fabricated a new type of waveguide polarization-independent optical circulator which does not need a polarization-beam splitter. The circulator is based on a non-reciprocal Mach-Zehnder interferometer which consists of two waveguide Faraday rotators, two thin-film half-waveplates and two planar lightwave circuit-type 3-dB couplers. The fabricated circulator provides a 14.0-23.7-dB isolation and a 3.0-3.3 dB insertion loss at λ=1.55 μm. This circulator presents a new possibility for developing non-reciprocal devices in the field of integrated optics     

Polarisation-insensitive high-isolation nonreciprocal device for optical circulator application

A novel high-isolation structure for a polarisation-insensitive nonreciprocal device intended for optical circulator application is proposed. It consists of birefringent crystals and polarisation rotators. Experimental demonstration shows an isolation of over 42 dB and an insertion loss of under 1.5 dB.<>     

Proposal for a polarization-independent integrated optical circulator

A polarization-independent waveguide circulator design is proposed which is well suited for monolithic integration. The circulator consists of multimode interferometers, half-wave plates, and Faraday rotators all in waveguide form. The length of the circulator is 712 /spl mu/m. Simulations show the circulator to have 25 dB of isolation and 1.3 dB of insertion loss at a wavelength of 1.55 /spl mu/m.     

光纤环形器中偏振棱镜系统的实验设计与制作

本文设计了一种新型的偏振棱镜系统,它具有损耗小、隔离度高、结构紧凑、调试方便等诸多优点。该偏振棱镜系统的损耗为0.6dB,隔离度为24dB。以此为基础做成的光纤环形器指标为,波长在1.3μm时,插入损耗(包括光纤对接损耗)∶2.2～2.4dB,隔离度∶20.5～23.1dB。     

基于磁性光子晶体的宽频带低损耗环行器

设计了一种基于光子晶体的结构紧凑、损耗低、频带宽的三端口三光路光环行器,该环行器由Y型光子晶体波导及配置在中心位置的磁光材料星形柱构成。通过对结构参数进行优化,该结构可以分别实现194~196GHz、198.2~199.4GHz和197~197.6GHz三个频段内稳定的顺时针单向环行传输,隔离度分别大于24、15.21和14.5dB,插入损耗分别小于0.18、0.11和0.38dB。该环行器结构简单,特别适用于结构复杂的光子集成系统,同时可提高光路的抗干扰性和稳定性等。     

光纤偏振控制器的原理、结构及特点分析

光纤偏振器具有抗干扰能力强，插入损耗小，易与光纤系统连接等优点，在光纤相干通信系统．以及光纤相干传感系统中受到重视。文中系统地讨论了电磁挤压型、可旋转光纤线圈型、可旋转光纤曲柄型、法拉第旋转器型、线性双折射光纤型，以及改进型和保偏光纤伸展型等光纤偏振器的工作原理和结构，分析了它们的特点，为新型光纤偏振控制器的设计提供了参考。     

High-isolation polarization-independent quasi-optical circulator

A polarization-independent quasi-optical circulator having high isolation over a wide wavelength range is reported. The proposed quasi-circulator is composed of two polarization beam splitters, two pentagonal prisms, two nonreciprocal rotators, and two walkoff polarizing beam splitters. Its structure is very simple. A three-port quasi-circulator has been fabricated with single-mode fibers. Its insertion loss and isolation have been measured to be ⩽1.7 and ⩾48.6 dB, respectively, at the nominal wavelength of 1.3 μm. A loss ratio of over 47.0 dB has been realized. The wavelength range over a 50-dB isolation between two fibers was measured to be about 50 nm     

New lumped element circulator by ceramic integrated circuittechnology

A broadband and a compact lumped element circulator was developed by a co-firing method of a ferrite and inner conductor. A circulator fabricated by this method with the dimensions of 6×6×3 (mm) showed a 20 dB isolation bandwidth of 7% and an insertion loss of 0.7 dB at 800 MHz. The gyromagnetic inductance of this circulator was compared to that of a conventional circulator. The former always showed a higher inductance than the latter. This measurement and additional measurement of the inductance for non-magnetized ferrite disks with and without a gap have shown that a great portion of permeability increase came from the elimination of the demagnetizing field in the element. Although a broadbanding was obtained, the insertion loss of 0.7 dB could be improved by using a more conductive material. To optimize the isolation bandwidth, a refinement of the design method based on the gyromagnetic inductance measurement should also be established. In spite of these problems, the magnetically closed circuit circulator, mC³, seems to be the ultimate lumped element circulator from its broadband characteristics, compact size and simplified structure, to reduce production costs. Furthermore, the broadband characteristics decrease the loaded Q-factor causing an increase in the handling power of the circulator which is a useful feature in broadcasting equipment