Effect of Overlaid Material on Optical Transmission of Side-Polished Fiber Made by Wheel Side Polishing

The performance of optical power transmission through a side-polished fiber on which materials of different refractive indices were overlaid is investigated. The experiments show that the transmitted optical power through the side-polished fiber varies with the refractive index of the overlaid material. The result of our experiments fits well the theoretical calculation. Side-polished fiber manufactured by wheel polishing method can be used not only to control optical power transmission through the fiber core but also as a refractive index sensor.     

A Convenient Organic–Inorganic Hybrid Approach Toward Highly Stable Squaraine Dyes with Reduced H‐Aggregation

A generic and effective approach for solving the aggregation effect observed with optical materials in solid state or in a solution with a poor solvent was explored by designing two types of squaraine‐containing polyhedral oligomeric silsesquoixane (POSS)‐based hybrids. It is expected that incorporation of “huge” inorganic POSS nanoparticles into optical materials via covalent bonding can effectively decrease the strong dipole–dipole and π–π stacking interactions, inhibit intermolecular charge transfer between adjacent squaraine molecules, and improve optical, thermal and chemical stability of the resultant materials. Both theoretical calculations and experimental results indicate that the molecular design strategy is rational and efficacious. The resultant organic–inorganic hybrid optical materials effectively eliminate the aggregation of organic optical chromophoric groups by hindering intermolecular charge transfer and decreasing dipole–dipole and π–π stacking interaction between the chromophores, and exhibit good optical stability, i.e., the absorption peaks of H1 and H2 display only a slight blue‐shift, even in the solid. Simultaneously, the hybrids also show significantly enhanced thermal, and chemical stabilities in comparison with the precursor organic optical materials.     

光纤AM CATV外调制发射技术

就光纤AMCATV外调制发射机的关键问题，即光源的选择、调制器的选择、非线性补偿、限幅失真抑制及CSO和CTB的闭环控制进行了较全面的论述。     

Balancing CapEx reduction and network stability with stable routing–virtual topology capacity adjustment (SR–VTCA)

This paper investigates the merits of the SR–VTCA (stable routing–virtual topology capacity adjustment) approach as a mechanism to find a beneficial trade-off between network stability and reduction in capital expenditures (CapEx). These are two main objectives for the entities that own the optical infrastructure, such as network operators (NOs), and those also acting as Internet service providers (ISPs). The SR–VTCA scheme is a novel approach to adapt transparent optical networks to time-varying traffic by adjusting the number of lightpaths between node pairs, while keeping the IP routing unchanged. Lightpath bundling (LB) and anycast (AS) switching are combined in SR–VTCA operation to advertise lightpath additions/removals to the IP layer as mere adjustments (increments or decrements) in the capacity, allowing to keep the IP routing stable, and thus, simplifying control plane operations. On the contrary, a fully-reconfigurable (FR) network design, where IP routing can be also modified, would increase the burden in the control plane, but at a higher CapEx reduction, since the optical infrastructure is used more efficiently. In this work, we investigate the CapEx overprovision introduced by SR–VTCA with respect to a FR scheme. In order to do this, SR–VTCA planning problem is first modeled as a MILP formulation. A heuristic procedure based on traffic domination is then proposed to solve large instances of the problem. Exhaustive experiments are conducted comparing the SR–VTCA solutions obtained by the aforementioned MILP and heuristic proposal with solutions found by other optimization methods presented in the literature to solve the FR planning problem. Finally, the results show that SR–VTCA can achieve similar results to the FR case in terms of CapEx reduction, while a huge number of IP reroutings are saved by maintaining IP stability. Thus, SR–VTCA provides an advantageous balance between CapEx overprovisioning and the control plane overhead associated with IP rerouting.     

用作EDFA光泵浦的激光二极管

近几年来,用作掺铒光纤放大器(EDFA)泵浦光源的半导体激光器,获得了积极的开发和使用。1.48μm 波长大功率激光二极管已商品化,并向更高水平发展。0.98μm 的应变量子阱结构器件也处在开发中,已有部分试用样品。文中介绍1.48μm 和0.98μm 波长大功率半导体激光器的主要结构和开发现状。     

纳米材料的电学、光学和光电性能及应用前景

简要介绍了纳米材料的电学性能以及单电子器件的基本原理和应用；纳米材料的光学性能和光电性能，高的光吸收系数和光致荧光现象可使其应用于敏感元件，由于其光电特性具有超快响应速度，可望在超快光电子器件中得到应用。     

基于光纤光栅传感器高压开关柜温度监测系统设计

本文针对高压开关柜温度监测问题,提出了一种基于光栅原理的温度监测系统。文章首先阐述了高压开关柜温度监测在电力系统中的重要性,其次对国内外目前的监测手段进行简要介绍,再次阐述了光线光栅的测温原理,最后对设计的光纤光栅温度监测系统进行阐述。本文依据光纤光栅传感器的测温原理,对高压开关柜温度监测问题进行了有益探索,对实际应用具有一定的指导意义。     

Petahertz communication: Harmonizing optical spectra for wireless communications

With the rapid deployment of Next-Generation Networks (NGN), the research community has initiated discussions on an entirely new suite of optical enabling techniques. To pave the way for the development of future wireless networks, this article aims to unify the existing infrared, visible light, and ultraviolet subbands while also exploring the potential of the Petahertz (PHz) band to support extremely bandwidth-thirsty telepresence style applications. Our focus is on the emerging Petahertz Communication (PetaCom) framework, scenario-dependent propagation channels, modulation schemes, system performance, multiple access techniques, and networking. We conclude with a range of PetaCom challenges and open research issues.     

椭圆芯保偏光纤模间干涉的研究

对椭圆芯保偏光纤的模间干涉现象进行了仿真研究,得到了其干涉输出光强分布同模间相位差之间的关系.将一种椭圆芯保偏光纤进行等面积矩形变换后,通过马卡梯里近似方法对两个低阶模式LP01模和LPeven11模的传输特性及传播常数进行了数值计算,得到了归一化传播常数和归一化截止频率之间的关系.通过实验得到了两个模式之间干涉模斑远场图样,表明椭圆芯保偏光纤的模间干涉特性可以应用于应力、电压等的测量.模间干涉将传感臂和参考臂集于一根光纤中,具有很好的抗环境干扰能力.     

Special Apodized Fiber Bragg Grating for Flat—top Band—pass Reflectivity Filter

The characteristics of special apodized fiber Bragg grating (FBG) in flat--top pass--band as reflectivity filter are presented. This special apodized FBG was designed by the particle swarm optimization algorithm. Compared with conventional apodized FBG, the special apodized FBG presented was more robust in the flat—top pass——band characteristic even if the strength of grating is very week. This technology is very interesting in designing the filter for wavelength division multiplexing system.