共面波导电极聚合物电光调制器多层结构研究

提出了两种基于共面波导(CPW)电极的多层聚合物电光调制器模型结构,分别为补偿层型结构和屏蔽层型结构。采用了保角变换的计算方法给出了基于CPW电极结构的多层电光调制器的特性参数的计算结果。与传统调制器结构性比较,补偿层型结构能够有效的减小光波与微波传输有效折射率的差,屏蔽层型结构不仅能够减小光波与微波传输有效折射率的差,而且能够通过优化结构参数,有效地消除了微波与光波之间的折射率差,可实现调制信号速率和调制电极阻抗的同时匹配。     

Ti:LiNbO3电光调制器中复杂截面形状行波电极系统微波损耗系数的计算和分析

本文给出了一种采用有限元法利用电感增量公式计算Ti:LiNbO3电光调制器中复杂截面形状行波电极系统微波损耗系数的计算方法.这一方法得到计算结果与其它计算方法所得的计算结果吻合较好.对本实验室和已发表文献中的一些调制器电极结构进行了计算,分析了计算和实测值偏差的原因,给出了在设计宽带Ti:LiNbO3电光调制器电极系统时微波损耗系数的修正因子.     

M-Z型LiNbO3外调制器的优化设计分析

阐述了以M-Z干涉型光波导为波导结构、铌酸锂(LiNbO3)材料电光效应为基础的集成光学强度调制器的工作原理及器件结构,讨论了集成光学强度调制器性能指标,重点讨论了干涉型行波电极结构LiNbO3外调制器的优化设计思想。     

Ti：LiNbO3电光调制器中复杂截面形状行波电极系统微波损耗系数的计算？…

本文给出了一种采用有限元法利用电感增量公式计算Ｔｉ：ＬｉＮｂＯ３电光调制器中复杂截面形状行波电极系统微波损耗系数的计算方法。这一方法得到计算结果与其它计算方法所得的计算结果吻合较好。对本实验室和已发表文献中的一些调制器电极结构进行了计算，分析了计算和实测值偏差的原因，给出了在设计宽带Ｔｉ：ＬｉＮｂＯ３电光调制器电极系统时微波损耗系数的修正因子。     

电光双向强度调制器的隔离度研究

设计和制作了应用于微波全双工收发系统的马赫-曾德尔型电光双向强度调制器。根据电光调制器中电信号对光信号的调制叠加原理,通过计算和仿真,分析了因调制电极设计电场与实际电场分布差异导致的器件隔离度劣化。通过对比不同调制电极结构的分析设计和仿真优化结果,得到3.5GHz以上频段隔离度优于-30dB的电光双向强度调制器设计结构。制备出的电光双向强度调制器在5~17GHz范围内隔离度优于-30dB。     

高速铌酸锂电光调制器研究进展

薄膜铌酸锂调制器因其小尺寸、高带宽、低半波电压等优点,成为近年来业内关注的热点。文章梳理了铌酸锂电光调制器的波导结构、电极结构及偏置点控制技术三个方面的相关研究进展,分析了平面掩埋、脊型、光子晶体等三种不同结构波导的调制器性能,讨论了铌酸锂调制器集总和行波两种电极结构的特点及其设计考量因素,对比了电光调制器偏置点控制中功率法和导频法的优缺点及其相关研究成果。在此基础上,进一步分析了为实现更小体积与更高带宽铌酸锂调制器所需的关键技术以及未来的研究方向。     

电光调制器

英国 Halbo Optics 公司生产一种 KD~*P电光调制器,能承受峰值功率达600兆瓦/厘米~2,连续功率达200瓦/厘米~2。这种电光调制器有三种型号,即 EOM1T 型,一个电极接地,单口输入,用于 Q 开关;EOM2T 型,一个电极接地,单口输入、输出,用于行波驱动     

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。     

微纳米PIN电光调制器的优化

在微纳米PIN电光调制器的基础上,分析了载流子浓度对其调制特性的影响。根据注入调制区载流子平均浓度随时间变化关系,采用在驱动信号中加入正反向预加重电压的调制电压方式,不仅可以提高注入载流子浓度,而且可以缩短反向抽取载流子所用的时间,从而有效提高电光调制器的调制速度;详细分析了PIN电光调制器结构中内脊高度H、外脊高度h,波导脊宽W以及重掺杂区到波导的距离Ws等参数对其调制特性的影响;最终根据数据的分析,给出了优化后的参数,制作了电光调制器并进行了测试,测试结果验证了文中数据分析的正确性。     

160GHz带宽LiNbO3电光调制器微波损耗的限制

本文通过模拟LiNbO3电光调制器的电传输特性,提出了厚电极共面波导（CPW）行波电极微波损耗的经验公式,在此基础上研究了带宽为160GHz的调制器的微波损耗因素。结果表明,辐射损耗将占重要地位,而且小的电极尺寸更易实现宽带调制。     

LiNbO3电光调制器行波电极微波等效折射率的测量

LiNbO3电光调制器的设计中，行波电极的微波等效折射率是一个重要的参数。该文通过自行设计的微波探针架及探针，采用差值的方法，在微波网络分析仪上对样品CPW电极的微波等效折射率进行了测量，分析了实测值与理论计算值的偏差，给出了修正因子，研究了微波等效折射率随频率变化的色散现象，并对这种测量方法进行了误差分析，提出了减小误差的方法。     

LiNbO3电光调制器行波电极微波等效折射率的测量

LiNbO3电光调制器的设计中,行波电极的微波等效折射率是一个重要的参数。该文通过自行设计的微波探针架及探针,采用差值的方法,在微波网络分析仪上对样品CPW电极的微波等效折射率进行了测量,分析了实测值与理论计算值的偏差,给出了修正因子,研究了微波等效折射率随频率变化的色散现象,并对这种测量方法进行了误差分析,提出了减小误差的方法。     

LiNbO3traveling-wave light modulator/switch with an etched groove

A Ti dffused lithium niobate traveling-wave interferometric light modulator/switch with a groove excavated at the electrode gap has been fabricated and tested at microwave frequency. The groove suppresses the undesirable light coupling between the two parallel waveguides for the phase shifting section so that the drive voltage is decreased by reducing the separation of the parallel waveguides, or of the electrodes. In addition, the groove decreases the effective index for the modulating wave to reduce the velocity mismatch between light wave and microwave so that the bandwidth is broadened. The modulation experiment was carried out from dc to 15 GHz at 633 nm light wavelength. For the modulator with the electrodes 6 mm long and 10 μm apart, the half-wave or switching voltage was 3 V, the extinction ratio was 18 dB, the 3 dB bandwidth was 12 GHz and aP/Delta fof 1.5 mW/GHz was obtained.     

Analysis and Demonstration of Mach–Zehnder Polymer Modulators Using In-Plane Coplanar Waveguide Structure

Analysis, design, and experimental demonstration of polymer Mach-Zehnder (MZ) modulators with a newly proposed in-plane coplanar waveguide (CPW) electrode are presented in this paper. Compared to the conventional CPW electrode, the new in-plane CPW configuration significantly enhances the overlap factor between microwave and optical wave by 40% from the theoretical calculations. Different from polymer modulators using the traditional microstrip electrodes, this structure can suppress dc bias voltage drift and widen modulation bandwidth. Using CLD1/APC and AJL8/APC electrooptic polymers, MZ modulators using the in-plane CPW are fabricated and tested. The measured Vpi's of the MZ with 15-mum gap spacing and 2 cm electrode length are 5.4 and 9.5 V at 1.55 mum for the AJL8/APC and CLD1/APC devices, respectively. The evaluated Upsi₃₃'s are 46 pm/V for the AJL8/APC and 26 pm/V for the CLD1/APC MZ. The dc bias stability is tested and compared for both the microstrip and the in-plane CPW electrode modulators. Experimental results show that the in-plane CPW modulator greatly improves the bias stability. From the microwave measurement, the microwave signal loss of the modulator using the in-plane CPW is much reduced to 0.2 dB/cmradicGHz, while 0.7 dB/cmradicGHz using the microstrip.     

Full-wave analysis of coplanar waveguides for LiNbO3optical modulators by the mode-matching method considering nonidealconductors on etched buffer layers

Rigorous analysis of traveling-wave coplanar waveguide electrodes for LiNbO₃ optical modulator applications is presented by using an extended full-wave mode-matching method. The microwave propagation characteristics under the composite influence of substrate anisotropy, uniform or etched buffer layers, finite electrode thickness and conductivity, and metallization undercutting are accurately assessed by employing a network equivalent formulation. Variations of the coplanar waveguide microwave effective index and the characteristic impedance at low frequencies due to finite electrode conductivity are illustrated, and are important even though the mode is quasi-TEM in nature. The effect of etching the SiO₂ buffer layer is shown to be one possible method for lowering the microwave effective index while keeping the conductor loss at a fixed level     

行波型LiNbO3电光调制器的电极优化设计

利用扩展点匹配方法对厚电极厚缓冲层的共面波导电光调制器的结构和性能参数进行了分析和研究,通过仿真选择合适的电极厚度和缓冲层厚度,所得的特性阻抗和有效折射率与采用保角变换法得到的结果吻合,优化了调制器性能,实现了宽带调制.这一分析方法简便快捷,能够处理电极有一定厚度的多层光波导调制器结构.     

LiNbO3waveguide modulator with 1.2 µm thick electrodes fabricated by lift-off technique

In order to make efficient high-frequency electrooptic modulators, the microwave loss in the electrodes has to be minimized. A lift-off technique using chlorobenzene to harden the top of AZ1350-J photoresist was adopted to fabricate 1.2 μm thick metal electrodes. A 1 cm long, 15 μm wide strip electrode has a dc resistance of 11 Ω, which is substantially less than that of the 2000 Å thick electrodes routinely fabricated. A 1 cm long traveling-wave phase modulator consisting of a single waveguide was tested. The measured -3 dB bandwidth is 3.8 GHz.     

电吸收调制激光器集成芯片的高频测试

提出了一种精确测试电吸收调制激光器(EML)集成芯片高频特性的方法。待测芯片制作在带有微带线的热沉上,同时采用光探测器作为光电转换器,二者构成待测双口网络。被测双口网络的一端是共面线,使用微波探针作为测试夹具加载信号,另一端是同轴线,两个测试端口不同,不能采用简单的同轴校准方法校准待测系统。测试过程中采用扩展的开路-短路-负载(OSL)误差校准技术对集成器件的测试夹具微波探针进行校准,扣除了测试中使用的微波探针对集成光源高频特性的影响,同时采用光外差的方法扣除了高速光探测器的频率响应对结果的影响,得到集成光源散射参数的精确测试结果。     

The transverse electrooptic modulator (TEOM): fabrication,properties, and applications in the assessment of waveguide electroopticcharacteristics

The fabrication of a novel electrooptic modulator with a transverse electrode geometry, formed by parallel electrodes on opposite faces of a thinned lithium niobate substrate straddling a strip waveguide, is reported. The device, referred to as a transverse electrooptic modulator (TEOM), has several advantages over standard electrooptic waveguide modulators using a coplanar electrode geometry. It is shown that it is possible to achieve a 30% reduction in the operating voltage for a given electrode spacing and a substantial reduction in the figure of merit, the power required per unit bandwidth, for electrooptic modulators with either lumped or traveling wave electrode structures. Moreover, a more accurate estimate of the electrooptic coefficients is possible than with modulators using strip waveguides and coplanar electrodes     

高效微带线聚合物电光调制器的研制

设计、制作并测试了1.55 m 光波长的微带线行波电极电光调制器。如果聚合物材料的电光系数33=30 pm/V,中心电极L 为20 mm,设计的调制器性能参数半波电压为6.70 V。用自主合成的发色团分子组成二阶非线性光学聚合物材料做为芯层制作的聚合物调制器,对调制器的各项性能参数进行了直流、低频和微波性能的测试,采用不同极化方法,在1.55 m 波长上测得低频半波电压分别为10.5 V(电晕极化)和4.9 V(接触极化),折算得芯层材料的电光系数分别为21 pm/V 和45 pm/V。测得消光比为24 dB。用矢量网络分析仪测试电极系统的微波性能,S 参数反映了此电极系统具有低的微波传输损耗和反射损耗。