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.

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.

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.

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.

Knot-inspired optical sensors for slip detection and friction measurement in dexterous robotic manipulation

Friction plays a critical role in dexterous robotic manipulation.However,realizing friction sensing remains a challenge due to the difficulty in designing sensing structures to decouple multi-axial forces.Inspired by the topological mechanics of knots,we construct optical fiber knot(OFN)sensors for slip detection and friction measurement.By introducing localized self-contacts along the fiber,the knot structure enables anisotropic responses to normal and frictional forces.By employing OFNs and a change point detection algorithm,we demonstrate adaptive robotic grasping of slipping cups.We further develop a robotic finger that can measure tri-axial forces via a centrosymmetric architecture composed of five OFNs.Such a tactile finger allows a robotic hand to manipulate human tools dexterously.This work could provide a straightforward and cost-effective strategy for promoting adaptive grasping,dexterous manipulation,and human-robot interaction with tactile sensing.

Characterization of refractive index distribution of polymer optical fiber

A focusing method is developed to characterize the refractive index profile of polymer optical fiber (POF). Based on the refractive index profile the theoretical bandwidth and the core index exponent a (a 】 0) of POF are calculated. The results show that the value of theoretical bandwidth agrees well with the experimental data.

A novel durable intelligent fiber reinforced polymer anchor with embedded optical fiber Bragg grating sensors

Anchors are the key members of the geotechnical anchorage engineering, it is urgent to monitor their behavior in service for preventing the potential risks. This paper proposes a novel durable intelligent fiber reinforced polymer （FRP） anchor to understand the behavior of the anchor in the field application. Series of optical fiber Bragg grating （FBG） sensors were embedded into the central axis along the anchor to sense itself axial strain variations. An evolution model of axial strain was also developed to evaluate the behavior along the anchor. A demonstration test was carried out to test its self-sensing properties in the laboratory. The experimental results indicated that the embedded FBG sensors monitored the behavior, e.g. axial strairl/interfacial damage evolutions along the anchor and displacement/applied load at the pulling end effectively, without influence from the interfacial compression and slip effects.

Liquid Level Sensor Based on CMFTIR Effect in Polymer Optical Fiber

The macro-bending induced optical fiber cladding modes frustrated total internal reflection effect is used to realize the liquid level probe with a simple structure of single macro-bend polymer optical fiber loop. The test results show that the extinction ratio reaches 1.06dB. ＂First bath＂ phenomenon is not obvious （about 0.8%）. The robustness of the sensor is better, and the ability of anti-pollution is stronger compared with the conventional sensors. The process of making this sensing probe is extremely easy, and the cost is very low.

Picosecond gain-switched polymer fiber random lasers

Random lasers are a type of lasers that lack typical resonator structures,offering benefits such as easy integration,low cost,and low spatial coherence.These features make them popular for speckle-free imaging and random number generation.However,due to their high threshold and phase instability,the production of picosecond random lasers has still been a challenge.In this work,we have developed three dyes incorporating polymer optical fibers doped with various scattering nanoparticles to produce short-pulsed random fiber lasers.Notably,stable picosecond random laser emission lasting600 ps is observed at a low pump energy of 50μJ,indicating the gain-switching mechanism.Population inversion and gain undergo an abrupt surge as the intensity of the continuously pumped light nears the threshold level.When the intensity of the continuously pumped light reaches a specific value,the number of inversion populations in the“scattering cavity”surpasses the threshold rapidly.Simulation results based on a model that considers power-dependent gain saturation confirmed the above phenomenon.This research helps expand the understanding of the dynamics behind random medium-stimulated emission in random lasers and opens up possibilities for mode locking in these systems.

High speed sub-micrometric microscopy using optical polymer microlens

We report the high speed scanning submicronic microscopy （SSM） using a low cost polymer microlens integrated at the extremity of an optical fiber. These microlenses are fabricated by a free-radical photopolymerization method. Using a polymer microlens with a radius of curvature of 250 nm, a sub-micrometric gold pattern is imaged experimentally by SSM. Different distances between the tip and the sample are used with a high scanning speed of 200 cm/s. In particular, metallic absorption contrasts are described with an optical spatial resolution of 250 nm at the wavelength of 532 nm. Moreover, finite-difference time-domain （FDTD） simulations concerning the focal lengths of microlenses with different geometries and heights support the experimental data.

Single fiber dual-functionality optical tweezers based on graded-index multimode fiber

We propose and demonstrate single fiber dual-functionality optical tweezers based on a graded-index multimode fiber. By using the multi-angle fiber grinding and polishing technology, we fabricate the multimode fiber tip to be a special tapered shape, contributing to focus the outgoing beam with a large intensity gradient for the first functionality--three-dimensional contactless trapping of a microparticle. By adjusting the radial direction offset between the lead-in single mode fiber and the graded-index multimode fiber, we perform the second functionality--axial shift of the trapped microparticle with respect to the fiber tip without need of moving the fiber probe itself. It is convenient for practical applications, The theoretical and experimental results about the relationship between the radial offset and the equilibrium positions of the microparticle have the good consistency. Tailoring the trap and axial shift of the microparticle based on the graded-index multimode fiber provides convenient avenues for fiber optical tweezers a~）Dlied in practical researches.

聚合物光纤发光面料的设计与开发

为了满足人们对纺织品个性化和多样化的需求,以聚合物光纤(POF)为发光体,依据光纤侧面发光原理设计开发聚合物光纤发光机织面料,介绍面料的灵感来源、光纤分布设计、组织设计、纱线设计及其排列、穿综设计、上机织造工艺等,在半自动打样机上进行试织并说明织造要点。结果表明:合理利用发光体和其他纱线,结合纬向管状组织、平纹小提花组织以及缂丝技术等,开发出更加时尚化、个性化的发光面料。发光面料主要应用于装饰纺织品,其结构独特、配色协调、立体感强,具有较强的装饰性和乐趣性,在一定程度上也起到安全警示作用。

Full distributed fiber optical sensor for intrusion detection in application to buried pipelines

Based on the microbend effect of optical fiber, a distributed sensor for real-time continuous monitoring of intrusion in application to buried pipelines is proposed. The sensing element is a long cable with a special structure made up of an elastic polymer wire, an optical fiber, and a metal wire. The damage point is located with an embedded optical time domain reflectometry （OTDR） instrument. The intrusion types can be indicated by the amplitude of output voltage. Experimental results show that the detection system can alarm adequately under abnormal load and can locate the intrusion point within 22.4 m for distance of 3.023 km.

基于光栅动画图案合成光纤织物的设计及其实现

通过光栅原理将动态画面用于织物设计时,易出现织物的双层结构复杂、色彩难以精准控制等问题,提出基于光栅动画图案合成原理设计动态图案光纤织物,利用提花工艺将光纤和纱线织造成图案织物,使用发光二极管作为光源,通过热塑管将其分别与聚合物光纤耦合连接,利用发光控制器,使得二极管依次间隔发光,显示相邻动作的静态图案。还分析了合成图片个数、切分用光栅细度、分组发光频率等对图案动态效果的影响。以光纤和棉纱为原料,采用提花织机设计和织造聚合物光纤织物,结果表明:当以直径为0.25 mm的聚合物光纤作为最小发光单元时,5帧数合成的光纤发光织物能够同时兼顾动画呈现的识别度和流畅度;间隔条纹宽度在0.25 mm时,动态效果呈现时,物体轮廓越清晰;当发光频率为0.2 s时,其呈现的动态效果最好。该思路开拓了织物上动态图案呈现的全新实现方法。

基于聚合物膜片和光纤复合结构的局部放电声传感器

本文提出了一种基于聚合物膜片和单模—多模—单模光纤复合结构的用于局部放电探测的声传感器。将长度为5cm的多模光纤植入单模光纤之间作为声敏感单元。当光从单模光纤进入多模光纤时,会激发光纤内的高阶模式形成干涉,以实现声传感,并将该光纤串入聚合物膜片中,用于改善其灵敏度。实验结果表明:该传感器在空气中的声传感灵敏度可达-30.8 dBm(0 dBm定义为1 V/μBar)。根据IEC 60270标准分别在空气和油介质中对传感器进行了局部放电声传感测试证明了该方案的可行性。由于其结构简单、成本低廉和不受电磁干扰等优点,该传感器有望在电力设备局部放电检测等领域得到应用。

基于光纤端面集成的液晶光束整形器件

光纤集成器件因其尺寸小、功能高度集成化等优点,近年来受到越来越多的关注。当前光纤集成器件通常由介质型或金属型微结构组成,其制备加工通常依赖于高精度的微纳加工技术,面临着成本高和工艺复杂等挑战。另外,静态、固定几何结构的光纤光学器件功能不可调,也在极大程度上限制了其应用范围。本文设计并验证了一种基于光纤端面集成的液晶光束整形器件。通过对单模光纤端面加工平行锚定和垂直锚定的液晶聚合物液滴,获得了可见光波段的光束整形器件。基于Q-张量模型和Rayleigh-Sommerfeld衍射理论,实现了具有特殊液晶指向矢排布的液晶聚合物液滴的模拟仿真。通过实验验证了不同锚定条件下液晶聚合物液滴的光学性能,实验结果与仿真结果基本吻合,证明了该液晶器件的光束整形能力。这种液晶器件为光纤光学器件的微型化与集成化提供了一种成本较低、高效便捷的全新途径。

聚合物光纤通信及传感研究进展

光纤技术的诞生使得信息传输速度显著提高,目前已经进入了光纤技术应用的全新阶段。在这个阶段中,聚合物光纤作为一种新型光纤备受关注,由于其材料的性质,比硅光纤更加柔软、轻便以及成本更低廉;同时,聚合物光纤的成型和处理方式也比硅光纤更加灵活,可以根据不同的需求和应用进行定制。随着制造和性能的不断改进,聚合物光纤在传输和传感领域都显示出了强大的潜力和多种应用的可能性,如光纤通信、物理研究、健康监测、生物医疗和环境监测等。介绍了聚合物光纤在上述领域的应用,总结了聚合物光纤在光纤通信和传感应用中的前景,最后指出了未来的研究方向。

一种新型共轭聚合物塑料光纤放大器材料制备及性能研究

针对传统塑料光纤在传输过程中损耗大,使用长度较短的问题,提出在光纤连接部位制备一种新型共轭聚合物CN-PPV掺杂塑料光纤放大器材料,并对其制备工艺、荧光特性和增益特性进行研究。试验结果表明,在25 mL MMA、0.032 g BPO、20~75μL n-BM的工艺条件下制备的预制棒表面状态良好,内部无气泡出现,并在拉伸温度为150~177℃的条件下成功拉丝。塑料光纤最大发射截面为1.7×10^(-20) m^(2);当泵浦光传输距离增加,光谱出现明显红移现象,最大红移波长为12 nm。在光纤长度为50 cm的条件下,掺杂质量浓度为1 mg/L的光纤存在最大增益值,达到25 dB。而掺杂质量浓度为0.2 mg/L的光纤具备持续光放大能力,更适合作为光纤放大器的制备材料。

A Novel High-Sensitivity Pressure Sensor: Thinned Fiber Bragg Grating with Pressure-Sensing Polymer

Based on thinned fiber Bragg grating and polymer material, we propose a novel high-sensitivity pressure sensor and obtained a new contribution to the pressure sensitivity, which is dependent on the derivative of the effective refractive index （RI） of core mode with respect to the surrounding medium RI, as well as on the relationship between the polymer RI and the pressure; moreover, it is inversely proportional to Young＇s modulus of the polymer material. For the polymer with Young＇s modulus of 1.0 MPa, the total pressure sensitivity 1.54×10-2 MPa-1 can be obtained.

高保偏聚合物光子晶体光纤的化学制备技术研究

研究了大尺寸高保偏聚合物光子晶体光纤(polymerPhotonicCrystalFibers,pPCFs)预制棒的化学原位制备技术.采用预聚物浇铸后加热聚合方法,成功制备了具有高保偏性能的光纤预制棒,给出了聚合反应的最佳条件.对此预制棒进行二次拉伸及光学和化学性质的测试表明,该方法得到的预制棒力学结构稳定、光学透明度高,且拉伸所得光纤微结构保持完好、微孔坍塌率低、非固有损耗小.若在聚合反应体系中加入适量的激光染料或其它稀土有机螯合物等物质,可得到具有荧光性的高保偏聚合物光子晶体光纤预制棒,为保偏型聚合物光子晶体光纤激光器的研制提供新材料.