熔融拉锥技术的新发展

本文对熔融拉锥技术作了全面简明扼要的介绍与分析，并对熔融拉锥技术（包括熔融拉锥机及器件）的发展历史及今后的发展方向作了分析。     

二氧化碳激光熔融拉锥系统

为了更精确地控制光纤熔融拉锥过程,利用二氧化碳激光器和自主设计改造的时间控制模块、光纤牵引模块搭建了二氧化碳激光熔融拉锥系统。在该系统中,设计时间控制模块对二氧化碳激光器的出光时间进行严格控制,找到单脉冲和多脉冲模式下的最佳功率参数和最佳时间参数,找到最佳热熔效果参数。搭建的二氧化碳激光熔融拉锥系统操作简单,可以提高熔锥型器件的精度。     

计算机控制的CO2激光熔融拉锥系统

针对现有熔融拉锥法(FBT)的缺陷,提出了一种CO2激光熔融拉锥系统。系统主要由CO2激光器、振镜和自动平移台三部分组成,通过计算机对其进行联合控制。试验结果表明利用该系统可精确控制熔锥光纤的形状,从而提高熔锥型器件的精度。     

基于熔融拉锥过耦合器的光纤光栅解调系统

提出了一种基于光纤熔融拉锥过耦合器进行解调的方法,实验制作了一个特殊的熔融拉锥过耦合器,对其输出的两路光功率进行了测试,并论证了用该耦合器进行解调的原理.利用该过耦合器组成的检测系统对光纤光栅传感器进行解调,得到了较好的响应.该解调方法成本低,结构简单,解调范围大,线性范围可达10 nm以上.     

制造熔融拉锥分支器件的工作台

介绍了已经被广泛应用的基于熔融拉锥分支（FBT）技术的光纤耦合器的制造设备，并从耦合器制造和新品开发的角度，提出了对工作台的结构和性能的要求。     

利用普通熔融拉锥机实现光子晶体光纤拉锥

光子晶体光纤的拉锥是实现光子晶体光纤潜在应用价值的重要技术手段。通过优化普通光纤拉锥机的参数,利用"快速低温"拉锥法有效控制了光子晶体光纤空气孔的相对塌缩。实验中实现了两种不同光子晶体光纤的拉锥,光纤外径分别从原来的125μm拉锥到50μm和30μm,光纤的孔直径和孔间距之比基本保持不变,拉锥损耗小于0.4 dB。基于普通熔融拉锥机的光子晶体光纤低损耗拉锥为光纤器件的制作奠定了基础。     

熔融拉锥型光纤耦合器损耗的实验研究

结合2×2熔锥型光纤耦合器的制作,实验研究了拉锥速度、耦合长度、火焰位置3个关键制作参数对耦合器的插入损耗和附加损耗影响。当拉锥速度控制在150μm/s时,耦合器的插入损耗和附加损耗可以控制在较低水平;在拉锥长度较短的区间内,插入损耗与拉锥长度基本成线性关系;制作低损耗耦合器,火焰存在最佳高度为5.75 mm。     

移动温区光纤熔融拉锥锥区形貌研究

光纤拉锥是光纤器件制作中的一项重要技术,为了研究快速往复移动温区熔融拉锥系统中锥区形貌与各拉锥参数的关系,基于体积不变原理,建立了往复运动温区熔融拉锥系统在满足温区运动速度大于光纤拉伸速度条件下的理论模型,详细描绘锥区形貌形成过程,推导出锥区直径、锥区平坦区长度与温区运动次数、温区运动速度、光纤拉伸速度、温区往复运动距离以及温区宽度与光纤初始直径之间的定量关系,并进行验证,实验结果与理论分析一致。     

ICCD的光纤耦合技术

文中主要介绍ICCD光纤耦合工艺技术的研究工作,并介绍了国内外相关技术的历史及发展现状。文中所述的ICCD的耦合工艺,继承了国肉研究的技术特点,同时,参考了国际上一些著名公司的相关技术,例如以色列的ORLIL公司、法国的PHOTONIS公司、荷兰的DEP公司和ADMEC公司、俄罗斯的ELECTRON公司等。因此,具有相当的先进性、代表性和参考价值。     

高功率光纤激光信号耦合器

实验研究了由三根信号光纤锥形束和一根多模光纤组成的3×1信号耦合器.通过仿真,发现锥形长度越长传输效率和输出光束质量越好,同时也验证了对于低阶模场的吸收要高于高阶模场.实验中,制作了锥区长度为10 mm的3×1信号耦合器,在单纤注入信号功率分别为258 W和365 W的情况下获得转换效率为96.6%的信号输出,总输出功率602W,光束质量为Mx2 = 10.5, My2 = 9.7.     

融熔型窄复用信道间隔波分复用器的研制

对如何实现偏振不敏感的窄复用信道间隔波分复用器进行了分析,采用熔融拉锥技术,实现了复用信道间隔为２５ｎｍ,波长隔离度为１８ｄＢ的波分复用器,并预计可以实现具有更窄复用信道间隔的波分复用器。     

CO2激光熔接型双包层光纤侧面抽运耦合器

为了把高功率的半导体激光器抽运光耦合入直径只有数百微米的双包层光纤内包层,以获得高的抽运功率,同时简化端面抛磨式熔接型侧面耦合器复杂的光纤处理工艺,提出了一种基于CO2激光熔接的双包层光纤侧面抽运耦合器的新方法,并进行了实验验证,介绍了试验装置和制作过程,制作了内包层直径为125μm非掺杂双包层光纤与105μm/125μm多模光纤的侧面耦合器,得到了82%的耦合效率测试结果。结果表明,所研制的熔接型侧面耦合器在侧面抽运的高功率双包层光纤激光器中具有很好的应用前景。     

High-power ns-pulse fiber laser sources for remote sensors

The development of fiber-based laser sources for space-borne remote sensors must meet many concurrent requirements including high pulse energy/peak power, excellent beam quality, narrow spectral linewidth, simple thermal management, small volume and mass, low power consumption, rugged packaging, and long-term reliability. To address these requirements, many aspects of pulse fiber laser technology must be advanced beyond the state of the art of traditional optical sources used in telecommunications and materials processing. In this article, we discuss component and solutions that enable pulsed fiber laser sources to support remote sensing from space. We also describe several examples of such sources and characterize their performance.     

Temperature-independent accelerometer using a fiber Bragg grating incorporating a biconical taper

An intensity-modulated optical fiber accelerometer is proposed and experimentally demonstrated by using a fiber Bragg grating (FBG) incorporating a biconical fiber taper. Acceleration-induced microbending of the fiber taper region introduces various attenuation to the light, so that acceleration can be measured from changes of the optical power of the reflected light from the FBG. This power detection method reduces the cost and complexity of the sensor setup since only photodetector is required for the signal detection. In the static measurement, a relatively large range of 5g (g is gravity, equals to 9.8 m/s²) with sensitivity of 4.85 nW/g is achieved. Vibration measurements have also been carried out with a frequency up to 20 Hz. The proposed accelerometer is nearly independent of temperature because the reflected optical power of the FBG is insensitive to temperature.     

Guidelines for design and fabrication of fused fiber coupler based wavelength division multiplexings

The fused fiber coupler can be function as WDM (Wavelength Division Multiplexing). An analysis of the wavelength response of the fused fiber coupler is presented here. Both theoretical and numerical methods are used to calculate the wavelength channel spacing of WDM at different pulling stop cycles. Experiments were carried out to testify the calculation results. A combination of theoretical and numerical method is used to predict the channel spacing of WDM. The calculation agrees well with the experimental results. This paper provides some guidelines for design and fabrication of the fused fiber based WDMs.     

熔锥型宽带保偏光纤耦合器的研究

熔融拉锥型宽带保偏光纤耦合器的制造工艺及其工艺参数的设置,对器件的性能有直接的影响.根据熔融拉锥型宽带保偏光纤耦合器的原理和光纤电磁理论,结合试验事实,对熔融拉锥的工艺进行了总结:实现了常规熔融拉锥型宽带保偏光纤耦合器的制作,并对产品进行了测试,完成了预期研究目标.     

On the formation of noise-like pulses in fiber ring cavity configurations

We give an overview of the current status of fiber-based noise-like pulse (NLP) research conducted over the past decade, together with presenting the newly conducted, systematic study on their temporal, spectral, and coherence characteristics in nonlinear polarization rotation (NPR)-based erbium-doped fiber ring cavity configurations. Firstly, our study includes experimental investigations on the characteristic features of NLPs both in the net anomalous dispersion regime and in the net normal dispersion regime, in comparison with coherent optical pulses that can alternatively be obtained from the same cavity configurations, i.e., with the conventional and dissipative solitons. Secondly, our study includes numerical simulations on the formation of NLPs, utilizing a simplified, scalar-field model based on the characteristic transfer function of the NPR mechanism in conjunction with the split-step Fourier algorithm, which offer a great help in exploring the interrelationship between the NLP formation and various cavity parameters, and eventually present good agreement with the experimental results. We stress that if the cavity operates with excessively high gain, i.e., higher than the levels just required for generating coherent mode-locked pulses, i.e., conventional solitons and dissipative solitons, it may trigger NLPs, depending on the characteristic transfer function of the NPR mechanism induced in the cavity. In particular, the NPR transfer function is characterized by the critical saturation power and the linear loss ratio. Finally, we also report on the applications of the fiber-based NLP sources, including supercontinuum generation in a master-oscillator power amplifier configuration seeded by a fiber-based NLP source, as one typical example. We expect that the NLP-related research area will continue to expand, and that NLP-based sources will also find more applications in the future.