一种低损耗低模式串扰渐变型少模光纤

提出了一种纯二氧化硅纤芯、渐变折射率分布的 两模光纤,实现了渐变折射率少模光纤低差分模式群时延和纯二 氧化硅芯光纤低损耗优点的有效结合。采用全矢量有限元方法研究表明,所提出的少模光纤 纤芯采用纯二氧化硅实现了 低损耗,采用纤芯渐变折射率实现了低差分群延迟,包层处采用凹陷折射率实现了低弯曲损 耗,采用模式大折射率差实 现了低模式串扰,采用大有效面积实现了低非线性系数;该光纤具有非线性系数和差分模式 群时延在1.5～1.65 μm波长范围内平坦特性。     

浅论纯二氧化硅纤芯光纤和PICVD工艺

本文对纯二氧化硅纤芯的 PICVD 光纤及 PICVD 工艺作了简要评述。这种纯二氧化硅纤芯的 PICVD 光纤有较宽广的低损耗皮长区,尤其是其在通常的短波长波段(860nm)有着极低损耗:1.3dB/km,优良的抗辐照性能。其单模光纤也可能有较宽广的低色散区域。文章指出了这种光纤的出现可能会大大加速光纤技术应用的推广,并使光纤技术再发展获得新的动力。     

纯硅芯石英光纤的研制

在简要阐述纯硅芯石英光纤结构、性能依赖关系的基础上，较详细地介绍了ＰＣＶＤ法制备纯硅芯光纤的工艺技术。为证实所制光纤性能的优劣，分别测试了该光纤的数值孔径，衰减系数和带宽等，提出了确保纯硅芯光纤良好性能的工艺方法。     

医用光纤

美国新泽西州Stirling的Fiberguide工业公司已为0.2～1.0μm波长的大功率传输设计了Superguide G全二氧化硅光纤。据该公司介绍,该光纤的纤芯采用高纯度二氧化硅,包层采用熔融掺杂高纯度二氧化硅。该光纤具有0.1～0.22的数值孔径。纤芯直径为25～1000μm。这些光纤的功率系数标准规范是1 kw/mm~2(连续波),1 Mw/mm~2(脉冲)。该公司能提供适合标准连接     

高折射率纤芯光子晶体光纤的特性研究

在二氧化硅中掺入适量GeO2可增大折射率，用其作为光子晶体光纤的纤芯时易于将光场捕获在纤芯中，形成稳定的传输模式。本文通过有限差分法数值解亥姆霍兹方程，研究了空气孔呈三角形典型结构排列的光子晶体光纤的特性．当纤芯及空气孔的大小都相同时，纤芯掺杂比例越高，光子晶体光纤的有效折射率就越高，色散则会向负向增长。此外，在这种高折射纤芯的光子晶体光纤中，当纤芯的大小及折射率均固定仅增大周围空气孔时，光子晶体光纤的色散增大，有效折射率趋于降低，模场有效面积也趋于减小。     

低损耗的单偏振光纤

日本电话电报公司茨城电气通信研究所的Y.Sasaki将于今年4月在美国菲尼克斯召开的光纤通信专题会议上作报告,介绍他们在试制单偏振光纤时进一步降低了光损耗方面的情况。它是一种保持偏振和降低了吸收损耗的光纤(简称PANDA),在1.54μm其损耗已低达0.4dB/km。这种PANDA光纤的纤芯和包层是采用人工合成的纯二氧化硅并通过VAD工艺制成的。在四周熔合的石英包层中,包含了由掺三氧化二硼的二氧化硅组成的二片附加物,其目的是为了     

大带宽,大数值孔径渐变折射率塑料光纤

为了解决高速多媒体网的单模二氧化硅光纤户外使用的连接问题，提出了一种新的大芯径渐变折射率塑料光纤。由于大数值孔径的渐折射率塑料光纤的制备，１０ｍｍ弯曲直径的损耗大大降低，从２０ｄＢ降到１ｄＢ以下。     

用加压MCVD法生产重复性好的极低损耗光纤

用加压MCVD法(改进的化学气相沉积)已获得极低损耗的光纤。就大数值孔径(NA=0.23)渐变型光纤而言,在1.58μm波长时,最低损耗为0.35dB/km。此项改进是基于予制棒内压和直径的流体动力学控制,并且是通过在一个加压设备和气体平行管道的热质流量控制器之间的一个反馈回路而获得的。通过予制棒加压,已制造出具有极高光学和几何重复性的纯二氧化硅包层和掺锗二氧化硅纤芯的光纤,在1.5至1.6μm波长范围内,其最小衰减值在0.35至0.55dB/km,圆整度和芯/包同心度误差小于1％。     

纯石英光纤的弯曲传输特性实验研究

报道了国产纯石英光纤弯曲特性的测量结果，得到了光纤的弯曲损耗与芯径、弯曲半径的关系曲线，并对测量结果进行理论分析。     

一种新型超低损耗大有效面光纤的技术研究

采用双包层的波导结构结合纯二氧化硅芯的技术方案,通过包层氟掺杂的设计与芯/包层之间粘度匹配的优化,实现了超低损耗大有效面积ULA-130型G.654.E光纤的制造,然后利用自行搭建的光纤非线性系数测量系统和自主设计的光纤宏弯损耗松绕设备,结合现有技术对ULA-130光纤的各项性能技术指标进行了研究。该光纤在1 550 nm波长的衰减系数为0.159 dB/km,有效面积为133 μm²,非线性系数为1.67×10^-10W^-1。理论计算与技术研究结果表明,该光纤具有优异的衰减系数和非线性性能,适用于大容量、高速率和长距离光通信骨干网传输系统,相对于常规的 G.652.D 光纤,可以显著改善系统的光信噪比,提升系统的传输性能。     

Transmission characteristics and reliability of pure-silica-core single-mode fibers

Transmission characteristics and reliability for pure-silica-core single-mode fiber with matched cladding are presented. On account of the "pure" silica core, without any additives, the fiber features the low attenuation and improved chemical stability under the existence of hydrogen and γ-ray radiation. High mechanical reliability and good splicing behavior of the fibers were also confirmed. More than 2000 km of pure-silica-core fiber have been fabricated, exhibiting median attenuation of 0.35 dB/km at 1.3 μm and 0.21 dB/ km at 1.55 μm. The achieved minimum attenuation was 0.154 dB/km at1.55-1.56 mum, which is the lowest attenuation ever reported.     

Low-loss pure-silica-core fibers and their possible impact on transmission systems

Low-loss optical fibers are now indispensable transmission media for transmission systems. Recently, the ultralow-loss performance for long transmission systems, the water-loss-free performance for wide-band wavelength-division-multiplexing (WDM) systems, the hydrogen-loss-insensitive performance for system reliability, and the bending-loss-insensitive performance for access or indoor applications have attracted much interest. In this regard, pure-silica-core fibers (PSCFs) are suitable, and unprecedented low-loss PSCFs have been successfully fabricated. This paper introduces the recent progress of low-loss PSCFs and their possible impact on transmission systems.     

Estimation of long-term transmission loss increase in silica-basedoptical fibers under hydrogen atmosphere

The irreversible loss increase in silica-based optical fibers due to hydrogen is discussed on the basis of results of various high-temperature tests. The results show that germanium-doped-core fibers have different behavior with respect to irreversible loss increase, and that a pure-silica-core fiber fabricated under optimum conditions is very stable against irreversible loss increase. The estimation of long-term transmission loss stability is also discussed, and high-temperature testing is certified to be effective for estimating the long-term loss stability under low temperature     

Water-free pure-silica-core fibre and its stability against hydrogen ageing

Water-free pure-silica-core fibre has been developed for the first time. It exhibits ultra-low loss of 0.247 dB/km at 1383 nm and 0.170 dB/km at 1550 nm, representing the lowest-loss G.652D fibre. Excellent durability against hydrogen ageing owing to pure-silica-core has also been verified.     

Highly accurate long-span chromatic dispersion measurement system by a new phase-shift technique

A highly accurate long span chromatic dispersion measurement system, which is based on a wavelength-division-multiplexing phase-shift technique and utilizes six laser diodes in1.2 sim 1.6 mum spectral region, has been developed. It is intrinsically free from error due to the fiber length variation caused by temperature changes under the measurement. The measurement accuracies of dispersion and Zero-dispersion wavelength are extremely good and within ±0.02 ps/km . nm and ±0.1 nm in 1250 ∼ 1450 nm spectral region in the case of a 10.5-km single-mode fiber measurement. The dynamic range is over 50 dB excluding system theS/Nmargin of 5 dB. Using this system, chromatic dispersion measurements of a 101.9-km pure-silica-core single-mode fiber and a 100.7 km concatenated dispersion-shifted single-mode fiber have been successfully carried out. The measured result has coincided with the arithmetical mean of those of constituent fibers.     

光敏光纤的研究动态

简要介绍了光敏光纤包括稀土元素掺杂光纤和塑料光纤目前在国内外的研究和发展状况。     

硫化物光纤及其功能器件的应用

本文概述了９０年代初兴起的硫化物光纤的独特性能、目前的发展状况及可能的应用前景;针对硫化物光纤实用化中的关键技术进行了分析,并对硫化纤的光敏机理作了一定的探讨。由于具有优于石英光纤的特点,硫化物光纤及其人器件具有广阔的应用前景。     

碲基硫系长波红外传输光纤的研究进展

碲基硫系光纤在2~16μm光谱范围具有优异的透射性能。近年来,它们作为长波红外传输介质备受关注。回顾了碲基硫系光纤的研究历史和现状,分析总结了用双坩埚法、棒管法、堆积挤出法和复合材料棒管挤出法制备碲基硫系光纤的特点,并对碲基硫系光纤的发展前景进行了展望。     

光纤消逝场传感器传感结构的分析与应用

对光纤消逝场理论进行了详细分析,阐述了影响光纤消逝场传感器灵敏度的一些关键因素,并对几种常见的光纤消逝场传感光纤的优缺点进行了比较,主要包括圆柱形、D形、U形、锥形以及光子晶体光纤等结构的传感光纤。通过分析各种传感结构的光纤消逝场传感器的应用实例,归纳总结了提高光纤消逝场传感器传感灵敏度的一般方法,包括在传感光纤表面镀薄敏感膜或者金属膜、优化传感光纤结构、进行荧光标记以及用纳米粒子修饰等一系列措施。     

现代单模光纤的改进及其制造技术

回顾了通信用光纤的发展历史，综述了最新发展的几种单模光纤，阐述了它们的几个关键参数与应用范围，描述了它们的制造技术。