M-Z型极化DANS聚合物电光波导强度调制器研究

研究了Mach-Zehnder型极化聚合物电光波导强度调制器的制备工艺.器件采用DANS (4-dimethylamino-4′nitro-stlibene)聚合物为电光波导材料,由电光波导层、上下介质缓冲层、上下金属电极层构成五层波导结构.对五层光波导各层之间的光学、化学以及微加工工艺的相互兼容性进行了深入研究.采用紫外光漂白方法制备出侧壁光滑的条波导,采用钨丝电晕极化方法对DANS聚合物波导进行有效极化,使其具有电光特性.通过优化器件制备工艺,研制出工作波长为1300 nm的M-Z型电光波导强度调制器原型器件.实验测得器件半波电压约为10 V,调制带宽约为1 GHz.     

新型极化聚合物薄膜电光调制器研究

用对硝基偶氮苯类为侧链的键合型聚合物，采用高温电晕极化的方法制作电光薄膜，设计并构造极化聚合物薄膜电光调制器。当通光方向和极化方向平行并且垂直于极化聚合物薄膜的表面时，利用法布里-帕罗（F-P）腔中多光束干涉，可以把通过的光由位相调制转化为强度调制，有利于电光调制器的小型化和高速封装。用这种聚合物薄膜电光调制器测量了锢锡氧化物共面波导上的电信号，并对系统的工作原理进行了分析。实验结果表明，薄膜调制器具有线性电光效应；当F-P腔的精细因子为20（为1.3μm的光），调制电场为1V/μm时，研制的极化聚合物电光调制器的调制深度可达到0.01%。     

对称推挽型有机聚合物电光波导调制器

提出了在极化有机聚合物民光波导调制器中使用局域极化结构。利用该结构，能够在电光调制器中实现完全对称的推挽操作。由于将集成光学电光调制器中用的平面电有改为使用眄结构的微带电极，并且将槽一结构用于接地电极，使器件性能发生变化。文中地反映光波与微波的相互作用强度的重叠积分进行了详细计算，并对器件性能的改变进行了比较。结果表明由于局域极化结构的使用，将大大提高器件的调制性能。     

SiO2脊形条波导热极化引起的电光效应

通过理论模拟对具有上覆盖层的SiO₂脊形条波导结构进行了优化，在此基础上利用微电子工艺制作了SiO₂脊形波导Mach-Zehnder型电光调制器，并进行热极化引起的电光和非线性效应的研究.热极化过程大幅增强了样品的电光及非线性效应，二次电光系数由热极化前的1.56×10^-22(m/V)²提高到热极化后的8.50×10^-22(m/V)²，极化后得到了0.093pm/V的线性电光系数，对热极化的物理机理进行了理论分析. 关键词： 电光调制器 2光波导')" href="#">SiO₂光波导 电光效应 热极化     

极性反应结构电光波导调制器的频域响应分析

本文详细分析了具有极性反转电极结构电光调制器的响应特性，推导出器件输出端振幅和相位的频率响应的解析表达式，并给出相应的数值计算结果。     

极性反转结构电光波导调制器的频域响应分析

本文详细分析了具有极性反转电极结构电光调制器的响应特性，推导出器件输出端振幅和相位的频率响应的解析表达式，并给出相应的数值计算结果．     

SiO2脊形条波导热极化引起的电光效应

通过理论模拟对具有上覆盖层的SiO2脊形条波导结构进行了优化,在此基础上利用微电子工艺制作了SiO2脊形波导Mach-Zehnder 型电光调制器,并进行热极化引起的电光和非线性效应的研究.热极化过程大幅增强了样品的电光及非线性效应,二次电光系数由热极化前的1.56×10-22(m/V)2提高到热极化后的8.50×10-22(m/V)2,极化后得到了0.093pm/V的线性电光系数,对热极化的物理机理进行了理论分析.     

高局域性的可调硅基混合表面等离子体光相位调制器

设计和分析了一种可调硅基混合表面等离子体相位调制器.表面等离子体的引入打破了衍射极限的限制,使光场局域在一个纳米尺寸范围.该调制器的实现采用了两种原理:硅材料的等离子体色散效应以及聚合物的电光效应.由于器件结构的电容和寄生电阻较小,RC响应时间为3.77 ps,调制带宽大约100 GHz.当外加2.5V的驱动电压时,该...     

一种具有高二阶非线性椭圆芯中空光纤

提出并制造一种新颖的椭圆芯中空光纤,采用热极化方法使其具有高二阶非线性,可用作相位调制器。该光纤在300℃温度、大于1×108 V/m强电场和9cm有效电极长度条件下热极化30min后,产生大的线性电光相移。基于双椭圆芯中空光纤构建一种纤内马赫-曾德尔干涉仪,通过观察干涉条纹的移动来评估相移,最终得到1.16pm/V的高二阶非线性系数和0.52pm/V的线性电光系数。该技术具有简单、灵活的特点,可以用来制作高电光系数器件,降低制作成本,并能进一步提高全光纤器件的集成度。     

推挽极化Y型耦合器电光调制器的傅里叶建模与表征

设计了一种高线性度、无偏置聚合物Y型耦合器电光调制器,它由Y型分束器、Y型合束器、两节推挽极化电光耦合波导构成的电光区和一个微带行波电极构成,给出了器件结构并对其参数做了优化。通过对施加的电学调制信号做傅里叶变换并结合器件的传递函数,给出了一种新型数值方法来建模和表征器件的静态和动态特性,推导并得到了器件的状态函数、静态响应、调制响应、三阶内调响应等表达式。计算和分析结果显示,器件的半波电压为2.69V;3dB调制带宽约为143GHz;当调制系数为1%~10%时,基频信号对器件所产生三阶内调噪声的抑制比为60dB~90dB。所给出的理论和相关公式也可用于具有Y型耦合器结构的类似电光器件(如电光开关)的设计、建模和分析。     

Electro‐optic polymer/titanium dioxide hybrid core ring resonator modulators

Compact electro‐optic (EO) modulators are desirable for a number of applications. In this study, a ring modulator has been fabricated in the titanium dioxide (TiO₂) core and EO polymer cladding waveguide structure. A 250‐nm thick TiO₂ core was utilized to minimize the ring radius down to 100 μm, to avoid using the top cladding between the EO polymer and the electrode, and to improve the poling efficiency. The resonance obtained by the ring modulator was observed to shift by 0.02 nm/V due to the enhanced in‐device EO coefficient of 105 pm/V. A modulation depth of 3 dB was observed at the frequency response function at 20 kHz using 2‐V V_p–p clock signal.     

Polarisation-insensitive strip-loaded waveguide for electro-optic modulators and switches

A polarisation-insensitive electro-optic (EO) waveguide consisting of a dye-doped TiO₂/SiO₂ slab and a SU-8 strip-loaded rib is designed and fabricated. By optimizing the refractive index and size of waveguide, a trade-off between polarisation-insensitive condition and large EO efficiency (optical field interaction with the EO material) is obtained. The average transmission loss of the waveguide is less than 2.0 dB/cm. A Mach-Zehnder (M-Z) interferometer intensity modulator based on this waveguide with excellent poling stability is fabricated and measured, exhibiting 7 V half-wave voltage with 1.8 cm EO interaction length and 2.7 cm total length. This strip-loaded structure is proved to be a valuable application in EO modulators and switches.     

Optimizing Design for the Traveling Wave Electrodes in Low-Drive High-Speed Electro-Optic Polymer Modulators

Electro-optic (EO) polymer modulators are very promising in the realization of cost-effective and high-performance optical transmissions. In this article, general strategies and specific designs of the traveling wave electrodes in EO polymer modulators were presented to reduce the modulator drive power while maintaining a broadband response. The optimum device parameters and corresponding conditions were estimated using finite element method based on electrode design. In calculating the results, the comprehensive characteristics of polymer modulator with 1.21 V half-wave voltage and 91 GHz bandwidth was demonstrated with electro-optic interaction length is 20 mm, electro-optic coefficient is 55 pm/V, and operation wavelength is 1.319 μm. These results agree with the 0.8 V half-wave voltage and 30 mm electro-optic interaction length reported in Science. In the five designs presented, a hybrid electrode structure combining CPW and microstrip lines were advanced. The characteristics of this structure are like that of microstrip lines with a single-arm electrode on one arm of the waveguide, but it solves the problem of microstrip to coaxial line transition and corona polarization.     

Optimizing Design for the Traveling Wave Electrodes in Low-Drive High-Speed Electro-Optic Polymer Modulators

Electro-optic (EO) polymer modulators are very promising in the realization of cost-effective and high-performance optical transmissions. In this article, general strategies and specific designs of the traveling wave electrodes in EO polymer modulators were presented to reduce the modulator drive power while maintaining a broadband response. The optimum device parameters and corresponding conditions were estimated using finite element method based on electrode design. In calculating the results, the comprehensive characteristics of polymer modulator with 1.21 V half-wave voltage and 91 GHz bandwidth was demonstrated with electro-optic interaction length is 20 mm, electro-optic coefficient is 55 pm/V, and operation wavelength is 1.319 μm. These results agree with the 0.8 V half-wave voltage and 30 mm electro-optic interaction length reported in Science. In the five designs presented, a hybrid electrode structure combining CPW and microstrip lines were advanced. The characteristics of this structure are like that of microstrip lines with a single-arm electrode on one arm of the waveguide, but it solves the problem of microstrip to coaxial line transition and corona polarization.     

Direct Fabrication Methods of Surface Relief Electro-Optic Gratings in Azo-Polymer Films

Two fabrication methods of surface relief electro-optic (EO) gratings in azo-polymer films are described: surface deformation by a continuous wave laser and laser ablation by a pulse laser. In the fabrication process, the periodic intensity modulation of laser beams is formed by an interference fringe or a phase mask. The surface relief EO grating is fabricated by poling the surface relief grating (SRG) after the SRG fabrication process. The linear dependence of an applied voltage in the modulation efficiency of the first-order diffraction beam is observed. The proposed methods are effective for highly-efficient surface relief EO grating fabrication.     

Dye-doped polymeric planar waveguide devices based on a thermal UV-bleaching technique

A new type of single-mode embedded dye-doped polymeric planar waveguide device based on cross-linkable negative photoresist has been successfully designed and fabricated using a UV-bleaching technique. A notable difference in the refractive index of the resist between exposed and un-exposed regions was observed, which was found to be dependent on the curing temperature. The new fabrication technique is a simple, rapid, and controllable process. The easy-to-fabricate waveguide structure is suitable for planar light-wave circuit applications. By optimizing the poling temperature and the dopant levels of Disperse Red 1, the material showed excellent photostability and exhibited a electro-optic coefficient, γ₃₃, of 25 pm/V. The dye-doped polymeric planar waveguide devices will be useful in realizing electro-optic (EO) modulators and switches.     

Development of a quasi-phase-matched, second-harmonic generation periodically poled lithium niobate waveguide with an integrated electro-optical modulator

A novel type of waveguide quasi-phase-matched device with output electro-optical (EO) modulation is proposed and demonstrated. The second-harmonic generated output can be modulated with a high extinction ratio by integration of dual EO phase modulators on a periodically poled lithium niobate waveguide. Blue and green coherent light with EO modulation was demonstrated, and wavelength dispersion of r33 is discussed.     

一种基于电光调制光频梳光谱干涉的绝对测距方法

提出了一种基于电光调制光学频率梳的光谱干涉测距方法.理论分析了电光调制光学频率梳的数学模型和光谱扩展原理,并分析得出了光谱干涉测距方法的非模糊范围和分辨力的影响因素.在实验中,使用三只级联的电光相位调制器调制单频连续波激光生成了40多阶高功率梳齿状边带,并通过单模光纤和高非线性光纤对电光调制器输出的激光进行光谱扩展,得到重复频率为10 GHz,光谱宽度达30 nm的光学频率梳.将该光频梳作为光谱干涉测距装置的光源,可以实现无"死区"的绝对距离测量.另外,使用等频率间隔重采样和二次方程脉冲峰值拟合算法对测量结果进行数据处理,可以修正系统误差,提升测距精度.实验结果表明,在1 m的测量范围内,使用该装置可以在任意位置达到±15μm以内的绝对测距精度.     

Carrier-envelope phase measurement by all-optical poling with a polar side-chain polymer

Dependence of all-optical poling efficiency on carrier-envelope phase (CEP) could be measured using photoisomerization of dye molecules which are covalently bound to a polymer main chain and have large difference in static dipole moment between the ground state and excited state. Increased chromophore density leads to an order of magnitude reduction in signal-detection time from a dye doped polymer. Analysis of all-optical poling experiments with CEP changes clearly showed the presence of polarization restoring force to zero polarization. This enables resetting of SH activity in the all-optical poling process to be used for fast response loop of CEP stabilization. Phenomenological model could explain well the difference in the growth-and-decay dynamics of poling between sample of dye doped in polymer studied previously and that grafted to a polymer main chain used in the present paper.