聚合物光纤传光束用光源及其应用（上）

聚合物光纤英文为：（POF）传光束用的光源一般为卤钨灯、发光二极管LED、激光二极管LD、荧光灯和金卤灯。不同的光纤传光特性不同，PMMA芯POF是紫外线可微量透过红外线极难透过的光纤，POF耦合和连接成本低，效率高，但要消除POF端面温升效应。POF传光束可用于汽车用照明系统中，并可实现一些新的照明功能，汽车中所用POF为传光传感用PMMA芯POF和耐热POF，数据传输用GI POF或SI POF。在日本、美国和欧洲的美术馆和博和馆已经采用POF照明这种新的照明方式，POF还可用于传感照明、舞会及演出或装潢照明、室内照明；POF传光束可作为高亮度光源用于静电印刷设备、背景光纤并可向水下输送光，进行光纤捕鱼和淡水养殖；在使用过程中应避免POF的过度拉伸和弯曲，防止有机溶剂对POF的侵蚀。     

第五讲 光纤数字开关与计数器

本部分主要介绍光纤数字传感器的四种基本工作原理，即：直射检测、回反射检测、散射检测和镜面反射检测。讲述了增益余量、对比度、光束直经、有效光束直径和光电接口等概念。最后介绍了光纤数字传感器在温度、压力、液面检测中的应用。     

聚合物光纤传光束的结构、特性及其制备工艺

普通聚合物光纤POF传光束可在70℃以下使用，耐温型POF传光束可在150℃以下正常使用。POF传光束具有一进一出、多进多出、环型、点线型和点阵型等类型，POF传光束在照明上具有许多优点，如可进行点照明、线照明和面照明，可任意设立照明角度，在狭窄的地点照明，简化仪表板的布局，使用耐久性，维修简便等；影响POF传光束特性的主要因素有POF的填充率、传输损耗、POF的弯曲、POF端面抛光状况及POF的耦合和连接等；采用单根POF所制备的传光束，其透光率可达70％／m以上，其填充率和透光率值最高。     

光纤输出光束的光强分布

本文给出了一个描写芯径较大的光纤输出光束的光强分布公式。该公式与光强分布的实数据相符合，并具有一定的通用怀，可用地外部调制强度型光纤传感器的调制机理分析及新型光纤传感器的设计。     

光纤输出光束的光强分布

本文给出了一个描写芯径较大的光纤输出光束的光强分布公式。该公式与光强分布的实测数据相符合，并具有一定的通用性。可用于外部调制强度型光纤传感器的调制机理分析及新型光纤传感器的设计。     

光纤F-P局部放电检测传感器优化设计

本文中作者根据高斯光束耦合理论、多光束干涉理论、弹性力学原理和有限元MEMS分析,对现有光纤型F-P传感器的结构进行了优化设计。     

照明电器专利摘要

1用于便携灯的椭圆反射镜和曲面透镜系统公开号:CN1902432A摘要:提供一种椭圆反射镜,其产生较小的圆形集中光束和亮度较低的更大的外部椭圆泛光光束。该反射镜的外缘为曲面,且提供一个匹配的曲面透镜用于覆盖该反射镜的外缘。该反射镜曲面外缘和曲面透镜使光束以更宽的水平光图案延伸,潜在地提供接近180°的照明。如果需要,例如,一部分光可以朝向下以照亮黑暗的路径。2作业灯系统公开号:CN1894538摘要:一种作业灯组件,包括能够在光输入和光输出端之间传输光的长柔性光纤元件;位于该光纤元件的光输入端的光源;以及用于支承该光源和该光纤元…     

聚合物光纤传光束用白光LED光源

介绍一种新颖的白光LED聚光灯,用于聚合物光纤（POF）传光束,以得到高效率和均匀的功率耦合。采用一种椭球反射镜（反光杯）,将普通T1-3／4封装的φ5mm白光LED出射光线会聚到15°角以内,可满足POF传光束的数值孔径要求。理论和实验结果表明,该光源输出光强分布均匀。     

基于光纤S锥的电力变压器油中微水传感研究

微水含量是衡量油浸式变压器绝缘性能的一个重要技术参数,实时跟踪变压器油中微水含量对保障油浸式变压器乃至整个电力系统稳定运行具有重要意义。为此,该文提出一种基于光纤S锥的微水传感技术。通过分析S锥形光纤的物理模型,构建S锥引起光强衰减与微水含量的量化关系,并利用光束传输法分析光纤S锥光束传播过程,评估锥腰直径、轴向偏移量等参数对S锥中基模、高阶模之间耦合程度以及高阶模的占比程度和持续长度的影响。制备不同结构参数的S锥光纤传感器,并开展不同微水含量的变压器油样中实测。结果表明,S锥光功率衰减幅值随油中微水含量增加而增加,S锥锥腰直径越细、轴向偏移量越大,对应S锥的检测灵敏度越高。对于锥腰直径为30μm、轴向偏移量为60μm的S锥光纤探头,检测下限达到4.67mg/L。可知,S锥传感器可有效实时跟踪变压器油中的微水含量,有助于及时发现变压器早期存在的绝缘受潮问题,保障其长期安全运行。     

基于双锥微钠光纤的GIS微水监测技术

GIS（气体绝缘封闭组合电器）内微水含量升高会降低其绝缘水平。为了实现对GIS内部绝缘气体湿度的在线监测,设计了一种基于双锥微纳光纤的GIS湿度传感器。首先采用BPM（光束传播法）对双锥微纳光纤的光场进行仿真,研究双锥微纳光纤的光场分布与模式干涉理论,得到SF6气体随微水含量的变化规律;然后采用熔融拉锥法制备了双锥微纳光纤湿度传感器,并进行了湿度传感实验。最后结合实验得出结论,基于双锥微纳光纤的湿度传感器检测灵敏度为-51.75 pm/%RH,能够实现对电气设备湿度的连续在线监测。     

Self-hold and precisely controllable optical cross-connect switches using ultrasonic micro motors

In this paper, we propose new optical cross-connect switches using ultrasonic micro motors, whose features are self-hold, precise control, and low electric power consumption. Two methods are examined for optical beam deflection. One method is moving the lens and the other is rotating the mirror by using ultrasonic micro motors. The light from the optical fiber is collimated using a self-focusing (SELFOC) lens and is deflected by moving the lens, with an ultrasonic linear motor, perpendicularly to the fiber axis. The light is then coupled to another fiber. Another proposed method is to use reflection mirrors. This structure is composed of a magnetized material attached to a micro mirror and a permanent magnet mounted on a shaft of an ultrasonic rotation motor. The reflected beam is deflected by rotating the mirror. In both methods, precise beam deflection is demonstrated, and optical switching characteristics are confirmed.     

Evaluation of PTCa/PEKK composites for acoustic emission detection

The electromechanical properties of calcium modified lead titanate/poly(ether ke-tone ketone) (PTCa/PEKK) composites and their ability after poling to detect acoustic emission (AE) when mounted on carbon fiber reinforced composite (CFRC) panels is reported. They have been characterized by measurements of conductance, G, permittivity, /spl epsi/, pyroelectric, p, and piezoelectric, d/sub 33/, coefficients for different ceramic volume fractions. In addition, the electromechanical coupling coefficient, k/sub t/, the elastic compliance coefficient, s/sub 33/, the acoustic impedance, Z/sub a/, and the quality factor coefficient, Q/sub m/ have been calculated from the measurement of the complex impedance (Z) of the composite samples acting as free resonating transducers. It is demonstrated that in a square array they can be used to locate AE sources with good accuracy and that they will also detect AE caused by the delamination of a CFRC beam.     

Thulium Fiber Laser Ablation of Urinary Stones Through Small-Core Optical Fibers

Complications during laser lithotripsy include optical fiber bending failure resulting in endoscope damage and low irrigation rates leading to poor visibility. Both problems are related to fiber diameter and limited by the holmium:YAG (Ho:YAG) laser (lambda = 2120 nm) multimode beam profile. This study exploits the thulium fiber laser (lambda = 1908 nm) beam profile for higher power transmission through smaller fibers. Thulium fiber laser radiation with 1 ms pulse duration, pulse rates of 10-30 Hz, and 70-mu m-diameter spot was coupled into silica fibers with 100, 150, and 200 mum core diameters. Fiber transmission, bending, and endoscope irrigation tests were performed. Damage thresholds for 100, 150, and 200 mum fibers averaged 40, 60, and > 80 W, respectively. Irrigation rates measured 35, 26, and 15 mL/min for no fiber, and 100 and 200 mum fibers. Thulium fiber laser energy of 70 mJ delivered at 20 Hz through a 100 mum fiber resulted in vaporization and fragmentation rates of 10 and 60 mg/min for uric acid stones. The thulium fiber laser beam profile provides higher laser power through smaller fibers than Ho:YAG laser, potentially reducing fiber failure and endoscope damage, and allowing greater irrigation rates for improved visibility.     

Spectral Combining and Coherent Coupling of Lasers by Volume Bragg Gratings

The use of volume Bragg gratings (VBGs) recorded in photo-thermo-refractive (PTR) glass for laser beam control is described. These new optical elements provide extremely narrow spectral and angular selectivity and have a high level of resistance to high-power pulsed and continuous-wave laser radiation. These features of PTR volume gratings are used for transverse and longitudinal mode selection, passive coherent coupling, and spectral beam combining (SBC) of semiconductor, solid state, and fiber lasers.     

Mode-scalable fiber-based chirped pulse amplification systems

A new generation of compact and robust ultrashort pulse lasers is currently emerging based on rare-earth doped fiber gain media. This paper reviews the development of high-power fiber technology, which recently has led to millijoule energies and ~10 W average powers from various femtosecond fiber systems. These results indicate that fiber technology has a significant potential to replace conventional solid-state lasers and promises important advantages both for practical use and for achieving high powers and energies. Chirped pulse amplification and different mode-size scaling techniques compose the foundation of this ultrashort-pulse fiber technology. Mode-size scaling can be achieved either by using multimode core fibers, which can produce a diffraction-limited beam at the fiber amplifier output, or by "mode-cleaning" of multimode core fiber output through saturated optical parametric amplification     

Spectrally Beam-Combined Fiber Lasers for High-Average-Power Applications

Spectrally beam-combined (SBC) laser systems, wherein multiple laser outputs are spectrally multiplexed into a single high-quality beam, are rapidly advancing the power scaling frontier for high-average-power beam-combined fiber lasers with near-perfect beam quality. We describe two- and three-channel SBC fiber lasers featuring 93% power-combining efficiency, near-diffraction-limited beam quality, average output powers in excess of 500 W, and excellent prospects for additional power scaling. To our knowledge, this level of optical performance represents the highest combination of beam quality and average power obtained so far for a beam-combined fiber laser system.     

The Effect of Amplitude (Power) Variations on Beam Combining Efficiency for Phased Arrays

In coherent beam combining (phased arrays), control of the relative amplitudes (powers) of array elements is needed to maximize the beam combining efficiency. Here, expressions are derived for the efficiency in approaches that use interferometric combiners such as diffractive optical elements or fiber couplers. The beam combining efficiency is relatively insensitive to small power errors. In the case of dropped elements, the efficiency is equal to the fraction of operating elements. The beam combining efficiency is equivalent to the Strehl ratio for a tiled aperture.     

无线通信在高压配电线路电能计量装置的应用

目前10 k V高压电能表主要采用光纤或无线通信传输数据,光纤硬件成本高且容易损坏。提出了基于35k V配电线路的新型高压电能计量装置应用无线通信技术,包括微功率无线和GPRS无线,实现本地与远程通信的信息采集与传递,分析了其设计要点与功能。并且提出了无线脉冲方式校表,提高装置的安全性、可靠性,降低硬件设计成本。     

GaInNAs: a novel material for long-wavelength semiconductor lasers

GaInNAs was proposed and created in 1995 by the authors. It can be grown pseudomorphically on a GaAs substrate and is a light-emitting material having a bandgap energy suitable for long-wavelength laser diodes (1.3-1.55 μm and longer wavelengths). By combining GaInNAs with GaAs or other wide-gap materials that can be grown on a GaAs substrate, a type-I band lineup is achieved and, thus, very deep quantum wells can be fabricated, especially in the conduction band. Since the electron overflow from the wells to the barrier layers at high temperatures can he suppressed, the novel material of GaInNAs is very attractive to overcome the poor temperature characteristics of conventional long-wavelength laser diodes used for optical fiber communication systems. GaInNAs with excellent crystallinity was grown by gas-source molecular beam epitaxy in which a nitrogen radical was used as the nitrogen source. GaInNAs was applied in both edge-emitting and vertical-cavity surface-emitting lasers (VCSELs) in the long-wavelength range. In edge-emitting laser diodes, operation under room temperature continuous-wave (CW) conditions with record high temperature performance (T₀=126 K) was achieved. The optical and physical parameters, such as quantum efficiency and gain constant, are also systematically investigated to confirm the applicability of GaInNAs to laser diodes for optical fiber communications. In a VCSEL, successful lasing action was obtained under room-temperature (RT) CW conditions by photopumping with a low threshold pump intensity and a lasing wavelength of 1.22 μm