紫外/可见光谱在有机光纤研制中的应用

有机光导纤维是近十几年来在新型光功能性高分子材料领域中的一支独秀.相对于玻璃光导纤维,有机光导纤维加工容易、口径大、轻而柔软、抗挠曲、抗冲击、耦合容易,更重要的因素是制作成本低和用途广泛.通常光导纤维是一种带包层的透明圆柱型的细丝.芯子的折射率高于包层并且是不变的,这种纤维称为突变型(SI)光纤.由于SI型光纤的带宽小,不能满足高信息量传输的需要,因而渐变型(GI)有机光纤得以发展.在这种光导纤维中,纤芯的折射率是呈抛物线型分布的,其轴心的折射率最大,折射率由纤维轴心沿径向到包层逐渐变小,在芯/包层界面处折射率无突变,光线在这种光纤的传播路径近似正弦波.沿正弦波处的折射率均小于轴心区的折射率.由于光速是反比于折射率的,因此当光沿着正弦途径传输时,其速度大于光沿着轴心传输的速度.于是,较长的光路被较大的光速所补偿,结果是光在正弦波处的传输时间与在轴心处的传输时间上没有大的区别,而脉冲加宽是正比于传输时间的差值,因此有望在GI型有机光纤中得到较小的脉冲加宽.GI型有机光纤的制备一般可在GI型有机预制棒的基础上通过熔融热拉技术拉制而成.因此,制备GI型有机预制棒及其折射率分布的检测成为关键步骤.折射率分布的测量方法有很多,如近场扫描法、折射近场法、切片干涉法等.本文首次介绍了将紫外/可见吸收光谱应用于预制棒折射率分布的定性测试上,得到了在预制棒芯区沿径向掺杂剂分子溴苯的吸收强度呈抛物线型分布.因测试折射率分布的其他方法较为繁杂以及受仪器的限制,所以利用紫外/可见吸收光谱这一非常普通的仪器来估计折射率分布的情况不失为一种简单易行的方法.     

多荧光光纤传感器及其在混合溶剂检测中的应用

微纳光纤与其他微纳结构的集成可以拓展荧光光纤传感器检测范围和集成度,是光纤传感领域的研究热点。目前,国际上关于荧光光纤传感器这一领域的研究还处于单一检测物荧光响应的阶段,对多检测物的多通道荧光响应仍存在很大挑战。本文结合微纳光纤的光波导性能以及有机荧光材料的光功能特性,制备了能够同时激发和收集多种荧光的微纳光纤,并将之应用于高性能荧光光纤传感器的制备。通过选用不同荧光波长的有机材料与凝胶掺杂,制备了多荧光发射的光纤涂层材料,可控构筑了多组分荧光检测剂掺杂凝胶涂层。利用荧光光谱结合色度图分析,确定检测物与色坐标的关系,实现了多检测物的多通道荧光响应,为实现多荧光光纤传感器的可控构筑提供了有益的借鉴和指导意义。     

长周期光纤光栅对铜离子的检测研究

利用有机反应在长周期光纤光栅表面制备了一层高分子材料敏感膜,用扫描电子显微镜(SEM)、X射线型能谱仪(EDX)等检测手段对高分子敏感膜层进行了分析表征,并利用敏感膜时溶液中的铜离子进行了光学检测。结果表明,该高分子敏感膜能够较好地确定铜离子的存在,证明了利用长周期光纤光栅对铜离子进行检测是可行的。     

高聚物光纤的研究进展

高聚物光纤具有模量低、直径大、柔韧等优点。它们在数据传输、显示系统、光敏元件上获得广泛的应用。介绍了高聚物光纤，特别是塑料光纤的研究进展，并提出将来的发展方向。     

光纤氧传感器技术进展

综述了近年来国内外光纤氧传感器技术的研究及应用情况,探索了光纤和荧光指示剂的进展,阐述了氧传感技术和制作氧传感膜的机理及光纤氧传感器的应用情况,并展望了光纤氧传感器的发展趋势。     

光纤探头式光度滴定法测定有机试剂及其金属配合物有关的物理化学常数

光纤探头式光度滴定法测定有机试剂及其金属配合物有关的物理化学常数曹中秋，杨建男，王忠厚，马成龙（辽宁大学化学系，沈阳１１００３６）用普通光度法测定配合物组成、稳定常数、配合反应质子释放数以及有机试剂解离常数已有多种方法，但均需配制一系列溶液，试剂消耗...     

梯度折射率塑料光纤的研究进展

论述了梯度折射率塑料光纤的研究背景。并对当前梯度折射率塑料光纤的制备方法,梯度折率塑料光纤的折射率梯度的形成机理的研究,及功能梯度折射率塑料光纤的研究状况进行综述。同时展望了梯度折射塑料光纤的发展趋势。     

层层自组装聚电解质膜光纤传感器的制备和应用

在过去几十年中,光纤的应用已经渗透到多个学科领域。光纤的抗电磁干扰、可远程监控、多重监测、体积小及质量轻等特点,使其在传感器研究领域备受关注。聚电解质层层自组装膜构建的光纤传感器自2000年诞生以来,已快速发展成为传感器领域新的研究热点。该类光纤传感器在微量物质的监测方面具有广泛的应用前景。本文从光纤和光纤传感器优点出发,总结了基于层层自组装多层膜的光纤传感器种类、性能、检测原理以及相应的光纤结构和自组装材料;进而结合作者已做的相关工作,论述了在光纤基底上的聚电解质层层自组装及基于自组装膜的光纤传感器的测试;重点综述了近十年层层自组装膜的光纤pH传感器、湿度传感器、气体传感器、生物传感器及其他类型的光纤传感器的制备与应用,并展望了今后聚电解质层层自组装多层膜光纤传感器的发展。     

含氟高分子材料在塑料光纤中的应用

近年来含氟高分子材料在塑料光纤中的应用使塑料光纤的各项性能得到了很大的改善.本文综述了当前含氟塑料光纤的研究进展,列举了几类已应用于塑料光纤的含氟高分子以及一些有良好应用前景的新型含氟高分子材料,简单介绍了几种制备塑料光纤的工艺方法.对氟塑料光纤今后的研究方向作了简要的讨论.     

温度对光学纤维自发喇曼光谱强度的影响

测量了不同温度下ＣＣｌ４液芯光纤喇曼光谱强度，实验结果表明，光谱强度随着温度的变化存在着一个极大值，对影响光纤喇曼光谱强度的几个主要因素进行了估算，理论与实验结果符合较好。     

Design,synthesis, and characterization of a partially chlorinated acrylic copolymer for low‐loss and thermally stable graded index plastic optical fibers

As a novel material of low loss and high thermal stability, a graded index plastic optical fiber (GI POF) comprised of a copolymer of methyl α‐chloro acrylate (MCA) and 2,2,2‐trichloroethyl methacrylate (TCEMA) was prepared and the thermal, mechanical, and optical characteristics were investigated. Although each homopolymer had low loss and desirable high thermal stability, they had crucial disadvantages for the fiber fabrication process. To draw a MCA polymer (PMCA) fiber, it has to be heated above 270 °C. However, the polymer started to decompose at a lower temperature and produced numerous bubbles. In contrast, TCEMA polymer (PTCEMA) is too brittle to roll up during heat drawing. In this study, we succeeded to improve the strong viscoelasticity and the low decomposition temperature of PMCA and the brittleness of PTCEMA by copolymerizing MCA and TCEMA. In addition, the glass transition temperatures (T_g) of the copolymers were in the range of 133–147 °C and the transmittances of the copolymers were much higher than that of PMMA which has been commonly used as a base material of POF. A suitable GI POF was obtained using the MCA and TCEMA copolymer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3352–3361, 2009     

耐热性有机高分子的性能研究及其在塑料光纤中的应用

本文以N 环乙基马来酰亚胺 (CHMI)和甲基丙烯酸甲酯 (MMA)共聚得耐热性透明材料 ,讨论了共聚产物的透明性和玻璃化温度与CHMI含量的关系 .以上述材料为基础 ,应用界面凝胶法制备光纤预制棒 ,在探讨了CHMI和PCHMI的折射率的基础上 ,分析并测试了光纤预制棒的折射率分布 ,最后拉制成塑料光纤 (GI POF)并测试了光纤的光透射窗口     

Progress in low‐loss and high‐bandwidth plastic optical fibers

Plastic optical fibers (POFs) are highly promising transmission media for future home networking.In comparison to glass optical fibers (GOFs), which are commonly used in core and metropolitan networks, POFs offer many advantages such as great flexibility and easy handling. This review begins with the basic concepts of optical fibers and moves on to the early history of loss reduction in POFs. What drastically changed the status of POFs in the communications field was a graded‐index technology that improved the bandwidth to over 1 gigabits per second. However, even after the loss and bandwidth were enhanced to their limits, the performances of POFs were insufficient for market demand when using conventional optical polymer materials such as poly(methyl methacrylate). Recently, this problem has been solved by several lines of material research using fluorinated polymers. As a result, high‐speed optical home networking by POFs has become more realistic. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

New amorphous perfluoro polymers: perfluorodioxolane polymers for use as plastic optical fibers and gas separation membranes

To address the need for perfluoro polymers with higher T_g, we have prepared and characterized various perfluorodioxolane monomers via direct fluorination of the hydrocarbon precursors. These monomers were readily polymerized in bulk or in solution initiated by perfluorodibenzoyl peroxide. The polymers obtained have relatively high T_g(~160°C) and exhibited low material dispersion. These polymers are completely amorphous and soluble in fluorinated solvents. The polymers are also chemically and thermally stable (T_g > 300°C). Thus, these perfluorodioxolane polymers may be used as plastic optical fiber material where high T_g is required, such as in automobile and aircraft application. These perfluorodioxolane polymers were also investigated for use as gas separation membrane. Among these polymers, the copolymer of perfluoro (2‐methylene‐1,3‐dioxolane) and perfluoro (2‐methylene‐4,5‐dimethyl dioxolane) showed superior gas separation performance compared with the commercial perfluoro polymers for a number of gas pair, including CO₂/CH₄, H_e/CH₄, H₂/CH₄, and N₂/CH₄. Copyright © 2015 John Wiley & Sons, Ltd.     

多模梯度（聚焦）型塑料光纤研究进展

多模梯度型塑料光纤，其折光 率径向分布呈连续的抛物线型分布。光在这种纤维中的行程按正弦波前进。这类纤维具有频带宽、传输容量大，信号保真度高的优点。本文就二十多年来有关ＧＩＰＯＦ的研究进展进行了较全面的综述。     

Estimation on the optic loss for acrylic polymers by theoretical modification

Various fluorinated/chlorinated polymers were synthesized and characterized by FT-IR and NMR. Also, theoretical optic loss of the POF were investigated and proposed for the purpose of finding a definite rule of the optic loss.From the computation of the results, the modified equation was theoretically deduced, and the optic loss of each prepared polymer was measured and compared with the calculated optical loss of polymers. Also, it was found that the optic loss from the modified equation fitted well with the experimental data.     

Status and dreams of photonics polymer for IT

We have proposed a low-loss, high-bandwidth and large-core graded-index plastic optical fiber (GI POF) in data-corn, area. The GI POF enables us to eliminate the “modal noise” problem which is observed in medium-core silica fibers. Therefore, stable high-speed data transmission can be realized by the GI POF rather than medium-core silica fibers. Furthermore, advent of perfluorinated (PF) polymer based GI POF network can support higher transmission than silica fibers network because of the small material dispersion of PF polymer compared with silica. In addition, we proposed a “highly scattering optical transmission (HSOT) polymer” and applied it to a light guide plate of a liquid crystal display backlight. The HSOT polymer backlight that was designed using the HSOT designing simulator demonstrated twice the brightness of the conventional taransparent backlight with sufficient color uniformity. Furthermore, we proposed the two types of zero-birefringence polymers synthesized by the random copolymerization method and the anisotropic molecule dopant method. Both of the polymers exhibited no orientational birefringence for any orientation of polymer chains.     

Optical Waveguiding Organic Single Crystals Exhibiting Physical and Chemical Bending Features

Bendable (elastic and plastic) organic single crystals have been widely studied as emerging flexible materials with highly ordered packing structures. However, even though manifold bendable organic crystals have been recently reported, most of them bend in response to only one stimulus. Herein, we report an organic single crystal of (Z)‐4‐(1‐cyano‐2‐(4‐(dimethylamino)phenyl)vinyl)benzonitrile, which bends under external stress (physical process) and also hydrochloric acid atmosphere (chemical process). This observation indicates that a single organic crystal, whose structure has been optimized simultaneously at both the molecular and supramolecular levels, may display multiple crystal‐bending modes. Furthermore, the crystals exhibit bright orange‐yellow emission and can serve as an active low‐loss optical waveguide in both the straight and the bent state, which indicates a potential optical application.     

Plastic colorimetric film sensors for gaseous ammonia

The preparation and characterization of three different plastic thin-film colorimetric sensors for gaseous ammonia is described. In the film sensors, the neutral form of a pH-sensitive dye (Bromophenol Blue, Bromocresol Green or Chlorophenol Red) was encapsulated in a plastic medium, either poly(vinyl butyral) or ethylcellulose plasticized with tributyl phosphate. Each of these film optodes gave a reproducible and reversible response towards gaseous ammonia. The sensitivity of the film sensors towards ammonia was found to be strongly dependent upon the pK _a of the encapsulated dye. Thus, the film with Chlorophenol Red (pK _a = 6.25), proved to be very insensitive (operating range: 0.29% < %NH₃ < 100%), whereas the film with Bromophenol Blue (pK _a = 4.1), was much more sensitive (operating range: 0.0003% < %NH₃ < 0.11%). The sensitivity of a plastic film sensor decreased markedly with increasing operating temperature and the 90% response (15–38 s) and recovery (820-127 s) times were slow and activation-controlled.