塑料光纤的技术发展及其应用

本文介绍了塑料光纤（POF）最重要的性能，包括POF的主要类型、制造及其目前和将来的应用，讨论了POF的带宽、误减特性及外部参数的影响。这些光纤可作为短距离通信链路用玻璃光纤的补充，因为它们易于加工、柔软且经济。由于这些优点，业已开发出不同的POF应用并已实用性，从用作简单的光传输波导作用作传感器和电信缆。本文全面介绍了POF。     

多模阶跃折射率塑料光纤带宽与数值孔径的分析

本文采用WKBJ法分析多模阶跃折射率塑料光纤（SI－POF）的传输带宽以及与数值孔径（NA）的关系,并结合多模SI－POF存在强的模式耦合,说明预期带宽和实测带宽间的差异;通过对光纤弯曲损耗等分析比较,说明NA既不能太大又不能太小。从而给出了短距离入户网中多模SI－POF的最佳NA适用范围。     

塑料光纤的发展与应用

在FTTH（光纤到户）广泛应用的推动下,塑料光纤（POF）展现出其巨大的市场潜力。详细介绍了POF的发展历程、关键技术及其性能,并叙述了POF的标准化情况及其主要应用,由此说明了开展POF研究的重要意义。此外还指出阻碍POF进一步发展的因素。     

GI-POF制造过程中气泡的消除

在用凝胶界面法制备梯度折射率塑料光纤(GI—POF)过程中遇到一些问题．其中制备预制棒和光纤过程中产生气泡等缺陷是影响传输损耗的主要因素，为此对该问题的产生原因进行了详细研究，并在此基础上提出了解决方案。成功地研制出直径0．5～1．0mmGI—POF。     

弯曲损耗减小的渐变折射率塑料光纤的波导参数设计

为了消除光纤的弯曲损耗，甚至是恶劣弯曲条件下的弯曲损耗，日本Keio大学的科研人员对渐变折射率塑料光纤（GI—POF）的波导结构，如折射率分布、数值孔径（NA）和芯径进行了适当设计。当芯径小于200μm、NA大于0．25时，GI—POF在恶劣弯曲条件下的弯曲损耗明显减小。当芯径为200μm、NA为0．24时，即使在恶劣弯曲条件下GI—POF的弯曲损耗也消失了。首次试验证实。由弯曲引起的模式耦合导致了弯曲损耗。光纤弯曲前的模式耦合强度对弯曲损耗有很大的影响。通过相邻模之间的传播常数差△β评定了模式耦合强度。随芯径和NA而变的△β影响弯曲损耗。因此，根据邸的计算结果，日本Keio大学的科研人员提出适当设计GI—POF的波导参数的指导性意见，以便抑制弯曲损耗。     

塑料光纤及其在FTTH中的应用

简要介绍了塑料光纤(POF)的发展,分析了传输损耗、色散、热性能等重要性能,并简要地描述了其在FTTH中的应用.     

聚合物光纤传光束填充率的计算(Ⅱ)

在聚合物光纤（POF）传光束中，POF可采用正方形、六边形或长方形排列，其端套可为正方形或圆形和六边形或长方形，通过计算得知，POF以六边形排列六边形端套成长方形端套时，POF传光束可获得较高的填充率值0.907；POF以正方形或六边形排列时，选用正方形端套POF传光束可获得填充率值0.785，POF以长方形排列长方形端套时，亦可获得这一填充率值0.785，POF采用其它方式排列和端套时，其POF传光束填充率值低于0.785；而选用单根直径POF及相应圆形端套制作传光束时，则其填充率值最高，皮层的厚度对POF传光束填允率影响较大，尤其对细直径POF传光束填充率影响更大，皮层厚度降低，可提高POF传光束填充率。     

基于POF的FTTH方案探讨

介绍了国内外光纤到户(FTTH)的研究进展,分析了FTTH在我国发展缓慢的因素及FTTH的成本构成,从降低FTTH的综合成本角度提出了在FTTH中使用塑料光纤(POF),描述了通信用POF的性能并给出了基于POF的FTTH方案,包括波长、光源、光电探测器和光收发器的选择.     

聚合物光纤传光束填充率的计算(Ⅰ)

在聚合物光纤(POF)传光束中,POF可采用正方形、六边形或长方形排列,其端套可为正方形或圆形或六边形或长方形,通过计算得知,POF以六边形排列六边形端套或长方形端套时,POF传光束可获得较高的填充率值0.907;POF以正方形或六边形排列时,选用正方形端套POF传光束可获得填充率值0.785,POF以长方形排列长方形端套时,亦可获得这一填充率值0.785;而POF采用其它方式排列和端套时,其POF传光束填充率值低于0.785;而选用单根粗直径POF及相应圆形端套制作传光束时,则其填充率值最高;皮层的厚度对POF传光束填充率影响较大,尤其对细直径POF传光束填充率影响更大,皮层厚度降低,可提高POF传光束填充率.     

聚合物光纤传光束填充率的计算(Ⅱ)

在聚合物光纤(POF)传光束中,POF可采用正方形、六边形或长方形排列,其端套可为正方形或圆形或六边形或长方形。通过计算得知,POF以六边形排列六边形端套或长方形端套时,POF传光束可获得较高的填充率值0.907; POF以正方形或六边形排列时,选用正方形端套POF传光束可获得填充率值0.785,POF以长方形排列长方形端套时,亦可获得这一填充率值0.785;POF采用其它方式排列和端套时,其POF传光束填充率值低于0.785;而选用单根粗直径POF及相应圆形端套制作传光束时,则其填充率值最高;皮层的厚度对POF传光束填充率影响较大,尤其对细直径POF传光束填充率影响更大,皮层厚度降低,可提高POF传光束填充率。     

梯度折射率塑料光纤上的波分复用数据传输试验研究

首先介绍了梯度折射率塑料光纤的制造方法和性能;其次阐述了在梯度折射率塑料光纤上进行波分复用数据传输试验的最新研究成果。     

光载射频信号在多模塑料光纤中的传输特性研究

实验研究了光载射频信号在多模塑料光纤(POF)中的传输特性,将24GHz的正弦波信号与1.5Gbt/s的数字信号进行混频后再通过光强度调制器产生双边带调制光信号,将双边带调制信号通过多模POF发送至接收机,在接收机转化为24GHz的射频信号。实验结果表明,这种双边带调制的光载波射频信号可以在多模POF中传输50m后而功率代价可以忽略不计。     

高带宽梯度折射率塑料光纤的数据传输试验

本文首先介绍了高带宽梯度折射率塑料光纤的制造方法和性能;其次阐述了在高带宽梯度折射率塑料光纤上进行的单信道和多信道的数据传输试验.     

High-Bandwidth Graded-Index Plastic Optical Fiber by the Dopant Diffusion Coextrusion Process

Today, the number of services, which includes large information contents like high-definition movies, is rapidly increasing. The graded-index plastic optical fiber (GI-POF) has been proposed as a solution. The conventional fabrication method of GI-POF, however, is unsuitable for mass production. Therefore, we propose the dopant diffusion coextrusion process for fabricating high-bandwidth GI-POF. It has been generally thought that formation mechanism of refractive-index distribution in optical polymer materials by this process would be a Fick's diffusion with constant diffusion coefficient and, therefore, has a tailing part at the core-cladding boundary. Contrary to predictions, we succeed in fabricating GI-POF with an almost optimum-index distribution. It is made evident by experiments and simulation that the formation mechanism of GI-POF by this process is a Fick's diffusion with diffusion coefficient dependent on dopant concentration. These results indicate high possibility of fabrication of high-bandwidth fibers of a polymethyl methacrylate-diphenyl sulfide system by the dopant diffusion coextrusion process.     

Control of Refractive Index Distribution for High-Bandwidth Graded Index Plastic Optical Fiber

The graded index plastic optical fiber (GI-POF) has been proposed as the transmission medium to realize high-speed information transmission. We have succeeded in fabricating a GI-POF by the coextrusion process, a method that allows continuous fabrication of GI-POF. Although it has been indicated that the refractive index distribution of GI-POF fabricated by this process is formed by Fick diffusion with diffusion coefficient dependent on dopant concentration, the method to control it remains unknown. The purpose of this paper is to establish the technology of controlling refractive index distribution in GI-POF fabricated by the coextrusion process. Therefore, we investigate the physical mechanism of the dependency of diffusion coefficient on dopant concentration. It has become clear that the dependency is affected by the decrease of glass transition temperature and the nonlinear increase of melt flow rate. Moreover, through simulation of dopant diffusion by our originally developed program, it has become evident that changing the molecular weight of the core and cladding material allowed control of fabricating a GI-POF with optimal refractive index distribution by this fabrication method.      

LDPC-Coded OFDM Transmission Over Graded-Index Plastic Optical Fiber Links

The possibility of 10-Gb/s transmission over graded-index plastic optical fiber (GI-POF) using the orthogonal frequency-division multiplexing (OFDM) and iteratively decodable codes is demonstrated by simulations. Several classes of low-density parity-check (LDPC) codes suitable for use in LDPC-coded OFDM transmission over GI-POF are presented as well. Several power efficient OFDM schemes are introduced     

塑料光缆的性能试验方法

文章首先介绍了梯度折射率塑料光纤的制造方法和性能;然后,阐述了塑料光纤光缆的性能试验方法和在梯度折射率塑料光纤上进行的数据传输试验的最新发展。     

Accurate refractive index profiling in a graded-index plastic optical fiber exceeding gigabit transmission rates

An optimum index profile offering the highest bit rate communication was formed in a poly methyl methacrylate (PMMA)-based graded-index plastic optical fiber (GI-POF) by modifying the polymerization process. The interfacial-gel polymerization process we have proposed to fabricate the PMMA-based GI-POF is capable of forming a nearly optimum refractive index profile. However, the theoretically calculated bandwidth from the measured index profile was reduced compared with a GI-POF with an optimum profile. In this paper, we report how to obtain a PMMA-based GI-POF having exactly the optimum index profile. The bandwidth of this ideal GI-POF was experimentally measured and a very high value of 2.88 GHz, even for a 150-m fiber length, was confirmed. The calculated bandwidth agreed well with the experimentally measured one. These results indicate that very low modal dispersion can be expected in a GI-POF fabricated by the modified interfacial-gel polymerization process.     

Formation of the refractive index profile in the graded indexpolymer optical fiber for gigabit data transmission

Bandwidth characteristics of the large core graded index polymer optical fiber (GI-POF) are theoretically and experimentally clarified. The refractive index profile of the GI-POF was controlled by interfacial-gel polymerization to investigate the relation between the index profile and the bandwidth characteristics. It was experimentally confirmed that the maximum bandwidth of the poly methyl methacrylate (PMMA) base GI-POF is at most 3 GHz for 100 m transmission using a typical laser diode emitting at 650-nm wavelength (3 nm source spectral width) when its refractive index profile is optimized. The maximum bandwidth theoretically estimated by considering both modal and material dispersions is approximately 3 GHz which is exactly the same as the measured value, while higher than 10 GHz for 100 m was expected if only modal dispersion was taken into account. The optimum refractive index profile of the PMMA base GI-POF is theoretically and experimentally clarified by considering the profile dispersion further     

High-bandwidth graded-index polymer optical fiber with high-temperature stability

A newly developed graded-index polymer optical fiber (GI-POF) with high-temperature and high-humidity stability was proposed. As it was found that the high numerical aperture and high glass transition temperature (T/sub g/) at the core center of the GI-POF were key issues to achieve both high-temperature and humidity stability, a partially fluorinated polymer material was adopted to obtain both characteristics in the GI-POF. The newly developed GI-POF had low-loss (140 dB/km at 650-nm wavelength), high-bandwidth (higher than 1 GHz for 100 m transmission), high-temperature and humidity stability at 70/spl deg/C, 80% relative humidity (R.H.) and low bending loss.