The Characteristics and Application of Polymer Optical Fiber

The recent development of polymer optical fiber (POF) at home and abroad was summarized.The special characteristics of the perfluorinated POF were introduced and its wide potential application was predicted.POF is the most suitable in conjunction network project,especially using with quartz optical fibers.Facing this market opportunity,it is a right choice to unit colleges,research institutions and manufacture corporations to accelerate the industrialization of POF.

Influence of Refractive Index Distribution on Brillouin Gain Spectrum in GeO_(2)-Doped Optical Fibers

GeO_(2) is commonly used as dopant to adjust the refractive index profile(RIP)and the acoustic velocity profile(AVP)in the fiber,thereby forming different Brillouin gain spectrum(BGS)characteristics such as Brillouin gain,acoustic mode number and peak intensity difference.When an optical fiber is used in optical fiber sensing or communication system,its BGS characteristics may play an important role in determining the performance of the system.In this paper,finite element analysis(FEA)method is used to study the influence of refractive index distribution and its corresponding AVP on the BGS in step-index,graded-index,and complex-index optical fibers.A new method has also been proposed to efficiently discriminate acoustic mode solution and obtain the new and full images of total Brillouin gain and acoustic modes number of the fiber as a function of the refractive index distribution,considering the influence of changing the refractive index difference and the geometric size simultaneously.For each type of optical fiber,the recommended parameter range is provided for optical fiber sensing and optical fiber communication.Moreover,the suitable optical fiber with close peak intensity in its multi-peak BGS is explored and achieved,which can be used in Brillouin beat spectrum detection systems to improve sensing accuracy.

Optimization of Spectral Inverters in Optical Fiber Communication Systems with Mid-Span Spectrum Inversion

In this paper, signal distortions caused by spectral inverters which are used in 10Gb/s optical fiber communication systems with mid span spectrum inversion in terms of dispersion shift fibers are analyed numerically. It is shown that there exist the optimal input signal power, fiber length and fiblter bandwidth for the spectral in verters. System transmission penalty can be minimized by optimizing these parameters.

Properties of Single Mode Polymer Optical Fiber

The density,dynamic modulus,Youngs modulus,tensile strength,extension properties,Fourier transform infrared spectrum and differential scanning calorimetry have been measured and discussed for single mode polymethyl-methacrylate optical fiber.The results show that the fiber can provide large strain range for polymeric optical fiber Bragg gratings.

Combined Transmission Interference Spectrum of No Core Fiber and BP Neural Network for Concentration Sensing Research

To investigate wavelength response of the no core fiber（NCF）interference spectrum to concentration,a three-layer back propagation（BP）neural network model was established to optimize the concentration sensing data.In this method,the measured wavelength and the corresponding concentration were trained by a BP neural network,so that the accuracy of the measurement system was optimized.The wavelength was used as the training set and got into the input layer of the three layer BP network model which is used as the input value of the network,and the corresponding actual concentration value was used as the output value of the network,and the optimal network structure was trained.This paper discovers a preferable correlation between the predicted value and the actual value,where the former is approximately equal to the latter.The correlation coefficients of the measured and predicted values for a sucrose concentration were 1.000 89 and 1.003 94;similarly,correlations of0.999 51 and 1.018 8 for a glucose concentration were observed.The results demonstrate that the BP neural network can improve the prediction accuracy of the nonlinear relationship between the interference spectral data and the concentration in NCF sensing systems.

Research on Radiation Characteristics of Polymeric Plastic Fiber

The anti-radiation mechanism of polymeric plastic fiber is analyzed. The radiation characteristic of this type fiber is studied. Our experimental results indicate that under the low radiation dosage (below 1 kGy) the plastic optical fiber’s transmission rate rises instead of descends while this type of fiber is radiated by γ ray, electron beam and proton beam respectively. After a period of time, it gradually reaches a constant value. But under the high radiation dosage (above 1 kGy) the fiber’s transmission rate descends after radiation. Later, it gradually goes up to a constant value.

Design of supercontinuum generating photonic crystal fiber at 1.06, 1.31 and 1.55 µm wavelengths for medical imaging and optical transmission systems

We propose broad supercontinuum spectrum generating highly nonlinear photonic crystal fiber (HN-PCF) which can be used in ultrahigh- resolution optical coherence tomography and optical transmission systems. Using full vector finite difference method, we investigated the different properties of HN-PCF. Broadband su-percontinuum spectrum is numerically calculated by using nonlinear Schr?dinger equation. Investigation showed that it is possible to obtain longitudinal resolution in a biological tissue of 1.3 μm, 1.2 μm and 1.1 μm by using picosecond continuum light at center wavelengths of 1.06 μm, 1.31 μm and 1.55 μm, respectively.

Monitoring the hydrolyzation of aspirin during the dissolution testing for aspirin delayed-release tablets with a fiber-optic dissolution system

The purpose of this study was to investigate the hydrolyzation of aspirin during the process of dissolution testing for aspirin delayed-release tablets. Hydrolysis product of salicylic acid can result in adverse effects and affect the determination of dissolution rate assaying. In this study, the technique of differential spectra was employed, which made it possible to monitor the dissolution testing in situ. The results showed that the hydrolyzation of aspirin made the percentage of salicylic acid exceed the limit of free salicylic acid （4.0）, and the hydrolyzation may affect the quality detection of aspirin delayed-release tablets.

Rapid analysis of piperazine ferulate tablets by optic-fiber sensing technology and the similarity of ultraviolet spectra

A rapid analysis method of piperazine ferulate tablets by optic-fiber sensing technology with UV-vis absorption spectrum was established. Qualitative and quantitative data were obtained and compared by maximum and minimum wavelength, absorbance and contrast spectra. Similarity method was used to identify authenticity of drugs. The difference of contents measured by this method and UV determination method in China Pharmacopoeia showed no statistical significance (P40.05), while the similarity can be used as a parameter to identify the authenticity of drugs.

Spectral analysis of the UFBG-based acousto optical modulator in V–I transmission matrix formalism

In this study, the V-I transmission matrix formalism （V-I method） is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating （FBG）-based acousto--opfic modulators （UFBG-AOM）. The simulation results demon- strate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave （AW） have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V-I method is 4 × （2M-l） in addition/subtraction, 8 × （2M - 1） in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix （TM） method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix （TM） method, the V-I method is faster and less complex.

Surface Plasmon Resonance Sensors Based on Polymer Optical Fiber

Surface Plasmon Resonance （SPR） is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering （SERS） probe. Long-period fiber gratings are fabricated on single mode polymer optical fiber （POF） with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.

Effect of PMD-induced Pulse Broadening on Sensitivity and Frequency Spectrum

The PMD-induced pulse broadening may cause the degradation ofreceiver sensitivity and has negative effects on the power spectrumof received signals. The expression s of PMO-induced pulse broadeningeffects on receiver sensitivity are derived based on the concept ofman square pulse width. The effects of PMD on the spectrum ofreceived power are analyzed in detail. Finally, the scheme isdiscussed with which the poser of a certain frequency component isextracted as a feedback control signal in a PMD compensation system.

Development of Flexible Luminous Fabrics for Photodynamic Therapy in Biomedical Applications

Fabrics integrating with side-emitting polymer optical fiber( SE-POF) have great potentials for photodynamic therapy( PDT),which is a form of phototherapy recognized as a treatment strategy that is both minimally invasive and minimally toxic.Preliminary research has been undertaken to develop flexible luminous fabrics( FLF) device for PDT used in biomedical applications. The FLF device consists of SE-POFs, textile substrates,light source( LEDs or laser) with proper wavelength,and optical fiber coupling,etc. Different patterns of the fabrics were designed and fabricated purposely,and the light illumination effect was tested including the light power emitting from the patterned optical fiber fabrics,the stability of the illumination,and the light with different wavelengths. The work contributes to the successful development of an efficient and pain-alleviated illumination device for PDT in biomedical application.

Novel Portable Oil Ingredient Instrument with Optical Fiber Link

The operation principle of a novel portable oil ingredient instrument is introduced. Using the theory of fluorescence measurement, this instrument can carry out fast and consecutive in-situ detection of oil ingredient in sea water, confirming fast and correctly the situation of oil contamination such as the concentration and the area, etc. The lowest detectable concentration for the instrument is 1×10 -8 g/ml with the precision of less than 3 %. The results of experiment and practice show that this system has well water-sealed characteristic and repeatability.

Anycast Transmission in Routing Modulation Level Spectrum Assignment (RMLSA) Problem on Space Division Multiplexing (SDM) Elastic Optical Networks (EON)

With the rise of cloud computing in recent years, a large number of streaming media has yielded an exponential growth in network traffic. With the now present 5G and future 6G, the development of the Internet of Things (IoT), social networks, video on demand, and mobile multimedia platforms, the backbone network is bound to bear more traffic. The transmission capacity of Single Core Fiber (SCFs) may be limited in the future and Spatial Division Multiplexing (SDM) leveraging multi-core fibers promises to be one of the solutions for the future. Currently, Elastic optical networks (EONs) with multi-core fibers (MCFs) are a kind of SDM-enabled EONs (SDM-EON) used to enhance the capacity of transmission. The resource assignment in MCFs, however, will be subject to Inter-Core Crosstalk (IC-XT), hence, reducing the effectiveness of transmission. This research highlights the routing, modulation level, and spectrum assignment (RMLSA) problems with anycast traffic mode in SDM-EON. A multipath routing scheme is used to reduce the blocking rate of anycast traffic in SDM-EON with the limit of inter-core crosstalk. Hence, an integer linear programming (ILP) problem is formulated and a heuristic algorithm is proposed. Two core-assignment strategies: First-Fit (FF) and Random-Fit (RF) are used and their performance is evaluated through simulations. The simulation results show that the multipath routing method is better than the single-path routing method in terms of blocking ratio and spectrum utilization ratio. Moreover, the FF is better than the RF in low traffic load in terms of blocking ratio (BR), and the opposite in high traffic load. The FF is better than the RF in terms of a spectrum utilization ratio. In an anycast protection problem, the proposed algorithm has a lower BR than previous works.

低损耗阶跃型塑料光纤(SI-POF)工艺的研究

介绍一种用高分子材料研制低损耗阶跃型塑料光纤 ( SI- POF)的新型工艺流程 ,采用甲基丙烯酸甲酯 ( MMA)与其他高分子材料共聚合成一种阶跃型折射率分布塑料光纤 ( SI-POF) .该光纤采用含氟树脂包层 ,可以降低损耗 .原料的精馏提纯、聚合反应、拉丝等整个工艺过程都处在一个密闭系统中 .探讨聚合反应方式对塑料光纤导光性能的影响 ,从而获得性能优异的塑料光纤 ,光纤的使用距离为 5 0～ 1 0 0 m,其导光性能为 :光损耗小于 2 0 0 d B/ km;数值孔径为 0 .35～ 0 .5

新型FRP-OFBG智能钢绞线的研制及其材料性能研究

通过用纤维增强树脂光纤光栅智能复合筋(FRP-OFBG筋)替换普通钢绞线中丝研制出了新型FRP-OFBG智能钢绞线。将智能钢绞线置于3 m拉索试验钢架台座上进行了静载试验,在5次循环加载后于第6次加载至破断,根据试验结果对FRP-OFBG智能钢绞线的应变传感性能及受力重复性能进行了研究。研究发现,智能钢绞线的感知线性度和重复性均较好,其承载力比不计FRP-OFBG筋强度的钢绞线的承载力略大,破坏形式为FRP-OFBG筋达到极限应力破坏后,钢绞线不滑丝并在中间位置破坏,可实现智能钢绞线破断的全过程监测,其最大应变可达9500με以上。结果表明,实用新型FRP-OFBG智能钢绞线是一种集应变感知和受力于一体的结构健康监测建筑材料。

分布式OFBG-GFRP传感筋在粘结性能试验中的应用

提出了一种新的利用分布式OFBG-GFRP智能传感筋研究GFRP筋与混凝土之间粘结特性的方法。在OFBG-GFRP的拉挤过程中,多个串连的光栅随同母材,即GFRP筋一同拉挤成型。早期的性能试验表明OFBG-GFRP筋不仅可以作为优良的增强材料使用,还具有理想的和稳定的传感特性。对3个带有OFBG-GFRP筋的混凝土粘结试件进行了直接拔出试验,在试验中自动记录了3个试件中的14个光栅的波长变化数据,这些数据连同记录的拔出力水平一起用来研究GFRP筋与混凝土之间的粘结性能。分析结果表明,GFRP筋与混凝土之间的粘结应变沿埋置深度基本呈现倒三角分布,且随着拔出力的增大,粘结应变分布也发生较为明显的变化,记录的光栅数据也很好地印证了试验过程中发生的试验现象。试验表明,所提方法可以在不影响FRP筋与混凝土之间粘结性能的情况下展开研究。

侧面发光的POF在照明中的应用

本文介绍了侧面发光POF的照明应用特点及其种类 ,着重介绍了侧面发光POF在建筑轮廓装饰照明、标牌显示、道路照明、室内照明和水下照明中的应用 。

新型的自参照型POF耦合传感器

基于POF(聚合物光纤)的工作原理,对影响全反射条件的各要素进行了认真分析,提出了一种全新的自参照型POF耦合传感器。通过对初始POF进行部分抛光和加入弯曲等处理,并引入耦合传感的理念,使传感器拥有了自参照特性。利用其耦合比K即可判断传感器所处的外部环境,它可以识别所在液体种类并可区分气液体间的变化。K并不受它所在链路或网络的传输功率波动或者不良功率的干扰,免去了较复杂的光源补偿过程。利用工业中常见的液体(水和油)对该传感器进行了测试和分析,其自参照特性、独立性以及温度特性都得到了研究,证实了耦合传感的优势。