A Low-loss Electro-optic Waveguide Polymer Modulator and its Optimization Design

Generally, the core is made up of EO materials in electro-optic waveguide polymer modulators and thus lightwave carrier is modulated in the core. In this case, the loss from chromophores is often large because the most of light power are confined to cores. In order to reduce the optical loss, we presented an approach that the lightwave was modulated only in claddings; that is to say, the EO polymer is only used in claddings and the core material is low-loss passive. Results indicate the propagation loss of this kind of modulator is about 1/3 of the former. Although the modal overlap integral between the microwave and the lightwave weakened under this condition, it could be improved by optimizing the dimension of waveguide. Due to the lower propagation loss, the interaction length of the modulator may be lengthened. Thus, the half-wave voltage can be decreased further. Also, some considerations on optimization design of this modulator are discussed. Especially, the effect of conductor loss and velocity mismatching should be taken into account in order to achieve the theoretical optimal half-wave voltage and the device bandwidth.     

超薄有源层谐振腔增强型调制器

提出利用超薄有源层制备高性能谐振腔增强型(RCE)半导体电吸收调制器件的可能性,并与波导型器件进行性能对比;对透射和反射两种类型器件优化分析了器件结构,进行了性能比较,结果表明:在插入损耗相当的情况下,反射式器件具有更高的调制对比度.     

可集成的高效率InGaAsP相位调制器

GaAs-AlGaAs和InGaAsP-InP体系光电波导调制器已日益引起人们的兴趣。预计它们可以用于高速光通信,相干光通信和激光陀螺。 本文报道一种用耗尽边带传输加反向偏压p-n结结构的高效InGaAsP/InP相位调制器。该调制器用液相外延、湿法腐蚀和常规工艺制备。这种波导禁带波长1.3μm的调制器在1.52μm波长观察到很大的相位移效率,对TE模和TM模来说分别为60°/V·mm和43°/V·mm。     

Design of novel three port optical gates scheme for the integration of large optical cavity electroabsorption modulators and evanescently-coupled photodiodes

This paper presents a novel scheme to monolithically integrate an evanescently-coupled uni-travelling carrier photodiode with a planar short multimode waveguide structure and a large optical cavity electroabsorption modulator based on a multimode waveguide structure. By simulation, both electroabsorption modulator and photodiode show excellent optical performances. The device can be fabricated with conventional photolithography, reactive ion etching, and chemical wet etching.     

15GHz马赫－陈德尔型Ti：LiNbO_3行波幅度电光调制器

比较了四种马赫－陈德尔调制器的结构特性，表明Ｚ切共面波导（ＣＰＷ）是最好的一种结构。用阶跃倒相电极设计了新型电光光波导幅度调制器，研制了包装式带尾光纤的有５段例相电极的马赫－陈德尔调制器。在１．５３２μｍ波长上，该器件调制带宽为１４．８ＧＨｚ，半波电压为１４Ｖ，消光比为２１．３ｄＢ，光纤－器件－光纤插入损耗７．６ｄＢ。     

Efficient design of silicon slot waveguide optical modulator

An optimal design of a slot waveguide is presented for realizing an ultrafast optical modulator based on a 220 nm silicon wafer technology. The recipe is to maximize the confinement and interaction between optical power supported by the waveguide and electric field applied through metallic electrodes. As height of waveguide is fixed at 220 nm, the waveguide and slot width are optimized to maximize the confinement factor of optical power. Moreover, metal electrodes tend to make the waveguide lossy, their optimal placement is calculated to reduce the optical loss and enhance the voltage per unit width in the slot. Performance of an optimally designed slot waveguide with metal electrodes as ultrafast modulator is also discussed.     

Wideband magneto-optic modulation in a bismuth-substituted yttrium iron garnet waveguide

We present a tunable wideband bismuth-substituted yttrium iron garnet (Bi-YIG) waveguide magneto-optic (MO) modulator. High-speed current transients are used to switch the in-plane magnetization of the film, which modulates an 800 nm optical beam. Large bandwidth optical modulation is achieved by driving the device in a non-resonant mode that is well below the ferromagnetic resonance frequency of the film. The MO modulator has the potential of operating at bandwidths higher than 1 GHz by tuning the applied static magnetic field.     

小型铌酸锂多功能集成光学器件

为满足小型光纤陀螺对光学器件小体积的要求,对铌酸锂多功能集成光学小型化器件的结构做了分析和优化设计。采用BPM软件分析了Y形分支波导的S形波导损耗与弯曲长度及折射率差的关系。通过调整退火质子交换的工艺参数,增加了波导对光的束缚能力;降低了小型化芯片上S形波导的弯曲损耗;去掉了原有Y形波导的输出端直波导,直接由S形弯曲波导引至输出端,在更短的芯片上得到了更长的弯曲过渡区。设计制作的芯片长度由常规的20 mm减至12.5 mm,封装后的器件长度减小到20 mm,为目前同类常规器件尺寸的2/3。设计制作的器件插入损耗典型值小于2.5 dB,全温损耗变化量小于0.2 dB。     

Three terminals optoelectronics devices integrated into a silicon on silicon waveguide

In this paper we describe two different kind of optoelectronic devices both based on a three terminals active device and exploit the plasma dispersion effect to achieve the desired working. The first device exploits this effect in order to obtain an optical modulation. The second device is an optoelectronic router based on the mode-mixing principle together with the injection-induced optical phase shift. Both devices are integrated into a Silicon on Silicon optical channel waveguide which can be realized using a standard bipolar process. The possibility of using standard, well-known technology presents several advantages with respect to III–V Optoelectronics. The active three terminal device used is a Bipolar Mode Field Effect Transistor (BMFET). Numerical simulation results are presented on both devices.     

基于有限差分束传播法的Mach-Zehnder型波导电光调制器的模拟设计

针对掺钛铌酸锂Mach-Zehnder型波导电光调制器的结构及折射率分布,运用有限差分束传播方法(FD BPM)进行模拟计算,取得了二维情况下的最佳设计尺寸.在此基础上,把所得的设计结果与原有的用快速傅里叶束传播方法(FFT BPM)所得的结果进行比较和分析.结果显示,运用有限差分束传播方法不仅取得了预期的结果,而且,这种方法比原有的快速傅里叶束传播方法更快捷和方便,是器件设计的理想和现实的数值模拟工具.     

基于双缝隙结构的电光调制器设计与工艺实现

受铜线带宽小、延时大、功耗高的限制,下一代芯片互连较为可行的一种解决方式是采用光互连.调制器作为其中的关键器件,有重要的研究意义.设计了一种新型的硅基双缝隙波导电光调制器,该调制器结构采用法布里-珀罗微谐振器,依靠缝隙内高非线性聚合物的快速电光效应,通过外加电压达到调制效果.调制器结构包含了新型的一般微纳波导到双缝隙波...     

Real-time non-linear spatial filtering with a leaky OASLM

In this paper we demonstrate image processing techniques such as edge enhancement and phase contrast by using an optically addressed liquid crystal spatial light modulator (OASLM) in the frequency plane of an optical 4f processor. The transfer function of the device is derived on the basis of the Jones formalism. Faced with a lack of a general theory for such non-linear optical processors, we show that an analogy to the propagation of optical pulses in fibres is helpful for the understanding of the image processing operation.     

SOI环形光波导谐振腔双层石墨烯调制器

在片上光互连系统中,电光调制器起到将电信号调制为光信号的作用,是光互联系统中的核心部件之一。调制器的3 dB带宽决定着载波所能携带的最大信息量,是衡量调制器性能的核心参数。利用石墨烯和高Q环形谐振腔设计成具有CMOS结构的新型调制器,其集成了石墨烯的宽带吸收、载流子迁移率高等材料优势和高Q值环形光学谐振腔的光程放大的结构优势,通过理论计算,其3 dB调制带宽可以达到100 GHz。同时,基于微环谐振腔的石墨烯电光调制器结构可以方便的与光互联系统中的波分复用器相集成,从而提升片上光互联系统的集成度和降低技术复杂性。     

0.73～1.7μm超宽带微纳光纤波导全光调制器

提出了单层石墨烯包裹双锥形微纳光纤复合波导结构,构建了730~1 700nm超宽带微纳光纤波导全光调制器。通过火焰拉锥法将一根标准的通信单模光纤拉成具有双锥形的微纳光纤,在保证通光率的前提下可以极大的提升微纳光纤处的倏逝波与物质的相互作用。利用石墨烯的"超级特征",即单原子层厚度、线性色散的能带结构、超强的载流子带间跃迁及极短的弛豫时间和超宽带光与物质相互作用等,将单层石墨烯作为可饱和吸收体,包裹在双锥形微纳光纤波导的锥体上,以增强该复合波导表面倏逝波与石墨烯的相互作用。静态和动态全光调制实验中采用传统808nm低功率LD作为泵浦光,对谱宽为480~1 700nm的超连续谱探测光实现了光光调制,其泵浦光功率低于50mW,调制深度大于5.7dB,调制速率达到~4kHz。该微纳光纤波导全光调制器,在保证调制深度的情况下,用更低的泵浦功率实现了超宽带的全光调制,以简单、有效、廉价的方式兼容了当前高速光纤通信网络,打开了一扇未来对微纳超快光信号处理的大门。     

Planar and Channel Optical Waveguide Loss Measurement Using Optical Phase Conjugation in BaTiO 3

A new methodology of the propagation loss coefficient measurement with an accuracy of at least 10 -3 cm -1 is demonstrated using a single-pass transmission measurement method and beam coupling based on a self-pumped phase conjugation process in a single BaTiO 3 crystal. A new, high-precision optical "bridge system" for routine measurement of the planar waveguide propagation loss coefficient is designed.     

Planar and Channel Optical Waveguide Loss Measurement Using Optical Phase Conjugation in BaTiO 3

A new methodology of the propagation loss coefficient measurement with an accuracy of at least 10 -3 cm -1 is demonstrated using a single-pass transmission measurement method and beam coupling based on a self-pumped phase conjugation process in a single BaTiO 3 crystal. A new, high-precision optical "bridge system" for routine measurement of the planar waveguide propagation loss coefficient is designed.     

GaAs脊型波导Mach-Zehnder干涉调制器

半导体电光波导调制器是半导体集成光学中具有代表性的器件之一,在光纤通讯、光信息处理等方面有着广阔的应用前景。它能和半导体激光器、探测器、电子线路等各种光、电元件实现单片集成,使设备和系统减少接口,缩小体积,提高可靠性。随着光通讯的发展,半导体调制器件的研究也越来越受到重视,在理论分析、结构设计、材料研制和器件工艺技术等方面也都取得了很大进展。由于GaAs材料具有良好的电、光性能,首先被用于制作GaAs光波导Mach-Zehnder干涉调制器中。     

Guide/antiguide optical intensity modulator

An electrorefractive index-controllable guide/antiguide optical intensity modulator has been created and characterized. The operating mechanism, beam propagation method simulation, device design and fabrication, and calculated and experimental results of this guide/antiguide modulator are given. The operational principle of the modulator is based on the field-induced waveguide (FIG) concept; that is, electric-field-induced refractive index changes cause the waveguide to be turned on and off electrically. The modulator is formed with a central narrow FIG electrode sandwiched between two antiguide electrodes. The electrooptic effects, along with carrier effects, have been exploited to adjust the refractive index under the guide and adjacent antiguide electrodes by changing reverse biases applied to them. The modulation is determined mainly by changing the lateral refractive index profiles. In the on state, a waveguide is formed under the central electrode, and the input light propagates along this waveguide. To realize the best off state, an antiguide situation is created that causes the light to diffract out of the central guide rapidly. An on/off ratio larger than 23 dB, a propagation loss 1 dB, and a record optical bandwidth from 1.0 to 1.55 m have been obtained for this modulator.     

4通道交叉型二氧化硅光波导延迟线阵列的设计与制备

设计并制备了一种高集成度、低成本、低损耗4通道交叉型二氧化硅光波导延迟线阵列。利用BPM软件对交叉结构光波导延迟线的Y分支的损耗、弯曲损耗进行数值模拟。综合考虑器件尺寸和损耗参数,设计交叉型延迟线结构的弯曲半径最小为1 500 μm,引入优化的锥口Y分支结构和垂直相交波导结构。采用标准半导体制作工艺制备器件,测试得到了器件的红外输出光斑,延迟线延迟时间分别为0、113、226和339 ps。4通道二氧化硅延迟线阵列能实现相邻通道相等的延迟时间间隔,且可通过集成实现延迟时间的增加,同时输出端可以与光纤阵列集成。     

Electro-optic modulation in hybrid solgel doped with Disperse Red chromophore

An electro-optically active hybrid solgel doped with Disperse Red 13 has been developed by use of a simple solvent-assisted method. It permits a high loading concentration and has low optical loss at 1550 nm. A channel waveguide amplitude modulator has been fabricated by use of active and passive hybrid solgel materials. The device shows an electro-optic coefficient of 14 pm/V at 1550 nm and stable operation.