Performance analysis of dual-pump optical parametric amplifiers in silicon waveguide

Nondegenerate Four Wave Mixing (FWM) process in a silicon waveguide is influenced by two photon absorption (TPA), TPA induced free carrier absorption (FCA) besides self-phase modulation (SPM), cross-phase modulation (XPM), SRS, GVD and linear scattering losses. Influences of pump parameters of the dual-pump parametric amplifier (OPA) in the silicon waveguide on gain spectrum and noise figure are numerically investigated. Compared with single-pump configuration, dual-pump silicon OPA indicates a flat gain and noise figure. Then impact of waveguide dispersion on bandwidth and ripples for dual-pump silicon optical parametric amplifiers is discussed. Optimal pump configurations are evaluated. The results show that polarization independent net gain of silicon OPA can be achieved by using circular and orthogonally polarized pump.     

圆碟中回音壁模式的耦合条件

基于波导的几何光学理论,并考虑谐振腔的品质因素或光子寿命,给出了毫米级圆碟回音壁模式谐振时的条件,应用光子隧道效应,分析了输入输出波导与圆碟的耦合特性,详细分析并给出了品质因素为5×105环形电极铌酸锂圆碟调制器中回音壁模式与波导的耦合与限制条件.提出一种利用铌酸锂Mach-Zehnder波导与同质材料圆碟构成的微波接收转换装置,该装置能够实现推挽操作,在具有较高频率分辨特性的基础上能进一步降低驱动电压,而且器件尺寸进一步减小.     

制备工艺对掺杂NaYF4:Er3+,Yb3+发光纳米晶的聚合物光波导放大器性能的影响

制备了NaYF₄：Er³⁺,Yb³⁺纳米晶,表征了纳米晶的形貌,通过物理掺杂的方式将纳米粒子掺杂到SU-8中作为光波导放大器的芯层材料,优化了波导放大器的尺寸,利用旋涂、刻蚀等工艺,在二氧化硅衬底上制备了光波导放大器。实验中用光漂白法和湿法刻蚀两种方法制备光波导放大器,分别给出了两种方法制备的器件的结构、工艺流程、光场模拟结果,并对两种方法制备的器件的放大特性进行了测试。测试结果表明,当980 nm波长的泵浦光功率为241 mW且1 550 nm波长的信号光功率为0.1 mW时,使用湿法刻蚀法制备的放大器得到2.7 dB的相对增益。当980 nm波长的泵浦光功率为235 mW且1 550 nm波长的信号光功率为0.1 mW时,使用光漂白法制备的放大器得到4.5 dB的相对增益。根据以上测试结果,分析了两种工艺对器件性能的影响。     

掺铒磷酸盐玻璃波导放大器的特性研究

研究了掺铒磷酸盐玻璃波导放大器的特性。利用重叠因子将980nm光抽运的掺铒玻璃波导放大器四能级模型的速率-传输方程进行化简,在考虑上转换效应和放大自发发射的情况下．利用数值模拟的方法,得到了掺铒玻璃波导放大器的增益与Er^3 离子浓度、抽运功率、波导长度等参量之间的关系曲线;同时模拟出放大自发发射曲线并与实验测量结果进行比较。结果表明在考虑上转换效应和放大自发发射的情况下,理论结果和实验测量结果是一致的。同时看到,选择合适的铒离子浓度是制作掺铒玻璃波导放大器的关键;并且为了全面发挥掺铒玻璃波导放大器的性能,需要抽运功率、波导长度等各个参量配合起来。     

锥形脊结构半导体光放大器的有限元分析

为提高半导体光放大器与单模光纤耦合效率，建立了半导体放大器的锥形脊结构模型。在该模型下利用有限元数值模拟方法分析，计算了波导区折射率、锥尖宽度、条形波导尺寸、渐变折射率波导层对锥形脊结构模式扩展的影响。通过完善锥形脊结构参量的设计，获得了锥形脊结构半导体光放大器与单模光纤95％的耦合效率。     

Optimization of erbium-doped waveguide amplifier

Based on the combined model of erbium-doped waveguide amplifier with high erbium ion concentration, the rate equation and evolution equation is solved numerically. The waveguide parameters such as doping concentration, waveguide length are optimized in this paper. With pumping power of 150 mW, the optimal erbium doping concentration and waveguide length is 6×10²⁶ m⁻³, 15 cm or so, respectively. The amplifier with these optimal parameters may reach gain more than 35 dB.     

阶跃掺杂Er∶Al2O3光波导放大器增益特性数值模拟

构建了纵向阶跃非均匀掺杂的掺铒Al2O3光波导放大器理论模型,利用有限元法、速率方程和传输方程,数值模拟了放大器的净增益特性.计算结果表明：阶跃掺杂掺铒Al2O3光波导放大器提高了抽运效率,净增益和信号光输出功率比优化后的均匀掺杂光波导放大器分别提高了9.2%和90.5%,长度却缩短了16.9%.     

Spectral distribution of photon pairs in a chirped waveguide

The spectra of two photon generation in the process of spontaneous parametric down conversion are studied in a waveguide containing the nonlinear segments with the spatial chirp. Three photon parametric interaction is investigated for the waveguide containing only a spatial fundamental mode. The peculiarities of spectra broadening of photon pair in the chirped waveguide are studied.     

基于KMnF_3∶Yb~(3+),Er~(3+)纳米晶的红光聚合物平面光波导放大器

制作了基于KMnF_3∶Yb~(3+),Er~(3+)纳米晶材料的工作波长655 nm的聚合物平面光波导放大器。材料的吸收光谱表明,KMnF_3∶Yb~(3+),Er~(3+)纳米晶在980 nm附近有很强的吸收。在980 nm激光的激发下,由于Er~(3+)和Mn2+能级之间的能量传递,KMnF_3∶Yb~(3+),Er~(3+)纳米晶产生了很强的红色上转换发光。根据KMnF_3∶Yb~(3+),Er~(3+)纳米粒子的发光特性,制备了KMnF_3∶Yb~(3+),Er~(3+)NCs-PMMA复合材料,用其作为芯层设计了掩埋形结构光波导放大器,利用传统的半导体工艺完成器件制备。器件测试结果表明,当655 nm信号光功率为0.1 m W、980 nm泵浦功率为260 m W时,器件获得了2.7 d B的相对增益。     

Quantum information processing through quantum dots in slow-light photonic crystal waveguides

We propose a scheme to realize controlled phase-flip gate between two single photons through a single quantum dot (QD) in a slow-light photonic crystal (PhC) waveguide. Enhanced Purcell factor and large β-factor lead to high gate fidelity over broadband frequencies compared to cavity-assisted system. The excellent physical integration of this PhC waveguide system provides tremendous potential for large-scale quantum information processing. Then we generalize to a multi-atom controlled phase-flip gate based on waveguide system in Sagnac interferometer. Through the Sagnac interferometer, the single photon adds the phase-flip operation on the atomic state without changing the photonic state. The controlled phase-flip gate on the atoms can be successfully constructed with high fidelity in one step, even without detecting the photon.     

Generation of quantum‐entangled twin photons by waveguide nonlinear‐optic devices

This paper reviews the quasi‐phase‐matched (QPM) waveguide nonlinear‐optic device technologies for generation of quantum‐entangled twin photons indispensable for quantum‐information techniques. After a brief introduction to the concept of entanglement, quantum theory analysis of twin‐photon generation (TPG) is outlined to clarify the properties of twin photons. Then, methods for entangled‐photon generation are discussed. Practical design and theoretical performances of LiNbO₃ waveguide QPM TPG devices, as well as the fabrication techniques, are described. Finally, experimental demonstrations of polarization‐entangled twin‐photon generation by waveguide Type‐I and Type‐II QPM TPG devices are presented.     

Er3+,Yb3+共掺磷酸盐玻璃沟道波导放大器

在自行研制的Er3 ，Yb3 共掺磷酸盐玻璃基质上用离子交换方法制作出沟导光波导放大器。在110mW的抽运功率下(抽运光波长为980nm)，在1．8cm长的器件上获得了3．8dB的小信号(信号光波长为1．55μm)增益，单位长度上的增益为2．1dB／cm。     

掺铒铌酸锂波导放大器增益特性的理论分析

对掺铒铌酸锂（Ｅｒ３＋：ＬｉＮｂＯ３）波导放大器在１４８０ｎｍ泵浦光单向和双向泵浦下的增益特性作了计算机模拟理论分析,采用二能级速率方程,忽略ＥＳＡ的影响,应用数值法得出方程解,优化设计放大器参数     

Dual-Core Leaky Waveguide-Based Filters for Erbium-Doped Waveguide Amplifier

Abstract

This article gives the design of a gain-flattening filter for an erbium-doped waveguide amplifier using a dual-core resonant leaky waveguide. The spectral variation of leakage loss of the waveguide has been used for gain equalization of the erbium-doped waveguide amplifier in the conventional (C) band. Leakage loss of the structure has been calculated by using the transfer matrix method. Numerical simulation results show a 17.5-dB gain with a gain excursion of ±1.35 dB in the C-band (1,526 nm–1,566 nm) of a typical erbium-doped waveguide amplifier. The study should be useful in designing integrated optic gain-flattening filters.     

激光器泵浦的波导染料放大器的研究

本文对波导染料自发辐射放大器进行了理论和实验研究。利用矩形波导模型求出波导模式、放大自发辐射阈值、放大自发辐射的近场及远场光强分布。实验获得放大自发辐射的远场光斑图样与理论计算比较基本一致,并对放大自发辐射输出特性进行研究。     

掺Er及Yb-Er共掺Al2O3光波导放大器的理论与实验研究

抽运波长为0.98μm时,考虑合作上转换、交叉弛豫、激发态吸收等上转换机理给出了掺Er及Yb-Er共掺系统的速率方程,并利用二维波导的有限元理论及包含正反向放大的自发辐射的场传输方程,建立了一套分析光波导放大器增益特性的综合理论模型。得到掺Er及Yb-Er共掺Al2O3光波导放大器增益与波导长度、抽运功率、掺杂浓度等多个参量的关系,绘制出具有实用性的优化设计曲线。将该理论模型应用于实际制作的Yb-Er共掺Al2O3光波导放大器,结果与实验数据相符。     

A Very Low-Noise Integrated 3MM-Wave Schottky Diode Mixer and PHEMT IF Amplifier

An integrated 3mm-wave Schottky diode mixer and pseudomorphic high-electron-mobility transistor (PHEMT) IF amplifier with record noise performance at room temperature is described. The design has shown the room-temperature double-sideband (DSB) receiver noise temperature T_R^DSB of 190 K at 100 GHz due to a very low conversion loss in the full-height waveguide mixer and an ultra-low noise of the PHEMT IF amplifier. The receiver noise temperature has been reduced by a factor of 1.5 in comparison with the best previously reported 3mm-wave Schottky diode mixer receiver.     

抽运光与信号光的光强重叠因子和掺铒玻璃波导放大器的增益特性

在掺铒玻璃波导放大器（EDWA）的三能级速率-传输方程中,考虑两次离子交换工艺中波导掩模窗口宽度w不同所导致的抽运光、信号光模场与光强分布的不同,讨论不同w对EDWA增益特性的影响,得到光强分布的数值解.引入描述波导中抽运光和信号光的归一化光强重叠因子,对EDWA的传统近似解提出修正,得到了修正解,使其更加接近光强分布的数值解.模拟结果表明,在条波导长度为4 cm、抽运光波长为980 nm、功率为80 mW、信号光波长为1534 nm、功率为-10 dBm条件下,不同w所导致EDWA的增益差别可达297 dB.修正解的结果比传统近似解更加接近光强分布的数值解.修正解对于EDWA的理论研究、器件设计具有指导作用. 关键词： 集成光学 掺铒玻璃波导放大器 重叠积分因子 增益     

Design of 1480-nm diode-pumped Er3+-doped integrated optical amplifiers

Abstact Erbium-doped Y₂O₃ integrated optical amplifiers are designed for low-threshold operation and 3 dB amplification. The most important design parameter for minimal threshold, the erbium concentration, is found to have an optimum value of 0.35 at% for a given waveguide structure with 1.0 dB cm^-1 background loss. The corresponding threshold power is 7 mW. The pump power to obtain 3 dB gain is found to be 22 mW for an amplifier with an optimum erbium concentration of 0.6 at% and 2.8 cm length. At 30 mW pump power the maximum gain is shown to be 5 dB.Designing is done using a comprehensive numerical model of an erbium-doped integrated optical amplifier. In the model two-dimensional intensity-dependent overlap integrals are used, which allow arbitrary erbium dopant profiles and waveguide crosssections. Concentration-dependent effects such as quenching and upconversion are also included in the model.Input parameters for the model are determined from measurements on an unoptimized Er: Y₂O₃ optical waveguide amplifier. Amplification simulations and gain measurements of the unoptimized waveguides are found to be in close agreement, providing a sound basis for the design calculations.     

掺铒玻璃波导放大器中抽运光信号光重叠因子分析

通过分析掺铒(Er3 )玻璃波导放大器(EDWA)的放大增益机理,提出抽运光与信号光光模场分布之间的归一化重叠积分因子(Γ),并引入到掺铒波导放大器增益模拟计算中,使理论模型更切合实际。以Ag -Na 二次离子交换工艺制作的具有埋入型渐变折射率分布的掺铒波导放大器为例,采用数值方法模拟了条形波导截面上的二维折射率分布及抽运光、信号光的光模场分布。计算了不同工艺参量设置下的Γ大小,讨论Γ对放大器增益的影响。结果显示,在二次离子交换制作过程中设置适当工艺参量优化折射率分布,能有效改善波导中抽运光与信号光光模场分布之间的重叠因子,提高掺铒波导放大器的增益。计算结果显示,在一定条件下,Γ从0.5增至0.8,每厘米长度掺铒波导放大器的放大增益可提高近1.5 dB。