1064nm低电压薄膜铌酸锂电光调制器

低半波电压电光调制器是实现大规模光电集成的关键。文章提出了一种半波电压低于1.5 V的薄膜铌酸锂马赫-曾德尔(Mach-Zehnder, MZ)电光调制器，选用绝缘体上单晶薄膜铌酸锂材料作为设计基础，分析了直波导、多模干涉耦合器、弯曲波导和调制臂等结构对电光调制器的影响。结果表明，当调制臂长为3 mm时，该薄膜铌酸锂电光调制器具有1.05 V的低半波电压、0.319 dB的低损耗和27 dB的高消光比。同时，该调制器半波电压长度积为0.315 V·cm,调制效率高，具有与CMOS技术兼容的半波电压，有利于大规模光电集成。     

高性能硅和铌酸锂异质集成薄膜电光调制器 （特邀）

硅基光子集成平台因其高集成度、CMOS工艺兼容性等特点在光通信领域受到了广泛的关注,而电光调制器作为光通信系统中最为重要的器件之一,承担着将电信号加载至光信号上的关键作用,为打破硅基调制器的性能限制,可利用硅和铌酸锂的大面积键合技术以及铌酸锂低损耗波导刻蚀技术实现高性能硅和铌酸锂异质集成薄膜电光调制器,目前该类调制器的性能可达半波电压3 V,3 dB电光带宽超过70 GHz,插入损耗小于1.8 dB, 消光比大于40 dB。文中对比了硅和铌酸锂异质集成调制器的研究现状并介绍了该异质集成薄膜调制器的结构设计与工艺实现方法。     

一种基于薄膜铌酸锂调制器芯片的新型电光调制器

针对传统铌酸锂电光调制器体积大、带宽小等技术问题,提出了一种基于薄膜铌酸锂调制器芯片的新型电光调制器的设计方法,给出了薄膜铌酸锂电光调制器高频传输仿真模型,详细介绍了薄膜铌酸锂电光调制器的高频信号馈入设计、过渡薄膜基板高频阻抗匹配设计,并测试了40 GHz小尺寸薄膜铌酸锂电光调制器的核心指标。测试结果表明：设计的薄膜铌酸锂电光调制器插入损耗、半波电压、3 d B带宽、产品尺寸分别为4.1 d B、3.9 V、40 GHz、30 mm×10 mm×5 mm,比传统铌酸锂电光调制器性能优越。     

基于铌酸锂薄膜的Y波导集成调制器设计

近年来,基于薄膜铌酸锂（TFLN）平台的高性能电光调制器以其小体积、低能量损耗等特点受到广泛关注。本文提出了一种新的具有垂直电极结构的Y波导铌酸锂薄膜电光调制器。研究了调制器的半波电压与缓冲层厚度之间的关系,优化了Y波导的设计参数,最后设计得到插入损耗<5 dB, 半波电压<1.5 V的高性能调制器。本文不仅为基于TFLN平台的小型化波导的设计和实现提供了思路,而且为制造高性能和多功能的电光调制器提供了实验依据。     

集成光学光纤陀螺芯片

本文首次报道了国内研制的集成光学光纤陀螺芯片,详细描述了其设计考虑与制作。单 Y 型多功能钛扩散铌酸锂芯片包含消光比大于35dB 的薄膜波导偏振器、分束比为49.5/50.5的3dB 分束器/合束器、半波电压小于5伏的相位调制器,光纤—器件—光纤插入损耗为5.4dB。     

用于微波光子系统的铌酸锂集成电光调制器研究

设计和制作了一种高速铌酸锂电光调制器。波导采用双Y定向耦合器型结构以提高线性度,同时能够提高工艺容差;电极采用CPW行波电极结构。通过分析比较不同相速匹配程度及微波损耗程度对电极系统带宽的影响,选择合适的设计参数及工艺参数,制作的调制器样品插入损耗为3dB,开关消光比为34dB,偏置电极半波电压为7V,行波电极半波电压为5.5V,电反射小于-10dB,6dB调制带宽约18GHz,可实现0～18GHz模拟调制。     

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。     

铌酸锂薄膜高速电光开关的设计与制备

基于硅基铌酸锂薄膜（Lithium Niobate on insulator,LNOI）材料平台，设计并制备了高速电光开关芯片，并实现了芯片的光纤耦合、管壳封装和性能测试。测试结果表明，该高速电光开关器件的开关速度达到13.4 ns，消光比达到31.8 dB。研究工作对未来研制光学延时芯片和波束形成网络芯片具有重要的支撑意义。     

铌酸锂低半波电压电光调制器研究

对降低铌酸锂(LN)电光调制器的半波电压进行了研究,探索了利用反射结构实现低半波电压的原理.通过退火质子交换工艺在x切LN晶片上制作了反射结构的LN电光调制器.测试表明,这种反射结构的LN电光调制器在保持器件长度不变的条件下可以降低半波电压.     

GaAs三波导耦合Mach—Zehnder干涉型强度调制器

本文报道了一种GaAs n~-/n~+脊型M-Z波导调制器,这种调制器用三波导耦合器作为分束器和干涉器。运用GaAs的电光特性,在λ=1.15μm下测量,得到半波电压14V,调制深度大于95％,3dB带宽大于1GHz的调制特性。     

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.     

High performance electro-optic modulator based on thin-film lithium niobate

Electro-optic (EO) modulator plays a very critical role in the optical communication systems. Here, we report a stimulated thin-film lithium niobate (LN) modulator with a half-wave voltage-length product of 1.8 V.cm, which can successfully achieve modulation and demodulation of a 1 GHz sinusoidal signal with an amplitude of 5 V in experiment. The optical loss caused by metal electrodes is reduced by optimizing the waveguide structure and depositing silica onto the waveguide, and group-velocity matching and characteristic impedance matching are achieved by optimizing the buffer silica layer and the electrode structure for larger bandwidth, which simultaneously improves the modulation efficiency and bandwidth performance. Our work demonstrated here paves a foundation for integrated photonics.     

High-Speed X-Cut Thin-Sheet LiNbO3 Optical Modulator With Folded Structure

We propose a small-footprint X-cut thin-sheet lithium niobate optical modulator with high-speed and low-driving-voltage characteristics. Since an optical waveguide is folded by a mirror placed at one edge of the modulation chip, the chip can be shortened by about half. In addition, a wide modulation bandwidth can be achieved, because the path-length difference between the optical waveguide and the coplanar-waveguide (CPW) electrode is decreased to as short as possible by placing the CPW electrode as far as possible along the optical waveguide in the folded portion, and the microwave effective index is set to realize effective velocity matching between the lightwave and the microwave. A small footprint of 1.78 times 29 mm, a low half-wave voltage of 2.0 V at dc, and a 3-dBe modulation bandwidth of 20 GHz were obtained.     

40 GHz, low half-wave voltage Ti:LiNbO/sub 3/ intensity modulator

A 5 V half-wave voltage (V/sub pi /) electro-optic Ti:LiNbO/sub 3/ intensity modulator with a -7.5 dB (electrical) optical response at 40 GHz is demonstrated at 1.3 mu m. A thick electrode structure is used in conjunction with a thin substrate to achieve a near optical-microwave phase match and a broadband electrical response.<>     

Optimization of Packaging Design of TWEAM Module for Digital and Analog Applications

Packaging technologies for a broadband and narrowband modulator with a traveling wave electroabsorption modulator (TWEAM) device were developed. In developing a broadband modulator, the effects of the device and packaging designs on the broadband performance were investigated. The optimized designs were obtained through a simulation with the result that we developed a broadband modulator with a 3 dB bandwidth of 38 GHz in the electrical‐to‐optical (E/O) response, an electrical return loss of less than ?10 dB at up to 26 GHz, an rms jitter of 1.832 ps, and an extinction ratio of 5.38 dB in a 40 Gbps non‐return to zero (NRZ) eye diagram. For analog application, the effect of the RF termination scheme on the fractional bandwidth was studied. The microstrip line with a double stub as a matching circuit and a laser trimming process were used to obtain an S11 of ?34.58 dB at 40 GHz and 2.9 GHz bandwidth of less than ?15 dB.     

实用化宽带半导体激光器组件的研制及其特性的研究

使用ＤＣ－ＰＢＨ型激光二极管芯片，设计制作了实用化封装形式的宽带半导体激光器组件，在理论上和实验上研究了组件的封装模型、小信号频率调制特性和非线性失真，其光响应为３ｄＢ，带宽大于２ＧＨｚ．该器件可满足六次群光通信系统的带宽要求，也可用于ＧＨｚ级微波副载波光通信系统．     

Ultra-high-speed multiple-quantum-well electro-absorption opticalmodulators with integrated waveguides

Integrating the input and output waveguides with a multiple-quantum-well (MQW) electro-absorption (EA) optical modulator is shown to achieve ultra-high-speed modulation while keeping the total device length long enough for easy fabrication and packaging. Testing with fabricated modulators showed that a shorter modulation region results in a larger modulation bandwidth. The additional loss due to the waveguide integration was less than 1 dB. An optimized modulator showed a large modulation bandwidth of 50 GHz, a low driving voltage of less than 3 V, and a low insertion loss of 8 dB. A prototype module of this modulator had a bandwidth of greater than 40 GHz. Optimizing the MQW structure makes the modulator insensitive to polarization. These results demonstrate that MQW-EA modulators with integrated waveguides are advantageous in terms of fabrication, packaging, and ultra-high-speed modulation     

High-speed low-voltage modulation with a nonsymmetric Mach-Zehnderinterferometer

The authors demonstrate broadband optical modulation with a Ti:LiNbO₃ nonsymmetric interferometer at microwave frequencies up to 16 GHz. The 3-dB bandwidth of 8.7 GHz is only slightly less than the theoretical limit of 9.6 GHz for a 1-cm-long device. The device uses a 2-μm-thick gold-plated asymmetric stripline electrode, with a characteristic impedance of 40 Ω and ohmic loss of 3 dB/cm at 10 GHz. The DC switching voltage is 6.5 V, and the on/off ratio is -16 dB. Fabrication tolerances in the nonsymmetric interferometer are much less strict than for directional coupler modulators with comparable performance, making this device a better candidate for use in communications systems