针对连续脉冲编码解码技术在分布式光纤喇曼温度传感器应用中出现被测光纤非线性峰值阀值光功率变低、编码过程较复杂等问题，提出了一种将光脉冲码均匀分布在整条被测光纤的单工循环编码解码技术和应用方案，并在27 km单模系统中与传统单脉冲技术系统做了对比实验.结果表明：相比连续编码解码技术, 单工循环编码解码技术不仅保持了编码解码技术相对于传统单脉冲技术的信噪比改善能力，而且有效地提高了光纤的非线性峰值阀值光功率.在编码时只需循环发送一组码，就可使系统的信噪比和测量距离获得极大的提高.采用211位循环编码解码技术的多模系统经16万次重复测量后，可在25 km处获得±1.5℃的温度不确定度，空间分辨率为3 m.

介绍了一种基于时分复用光纤传感技术的准分布折射率传感器。通过测量光纤端面的菲涅耳反射信号的强度，实现对待测溶液折射率的分布检测。在多个测量点之间采用不同长度的延迟光纤，利用不同传感位置处的菲涅耳反射信号回到测量端的时间差来实现距离可分辨的多点测量。实验结果表明该传感器的测量距离达16 km，测得折射率范围为1.3486~1.4525，对应的灵敏度范围为38.785~305.430 dB/RIU(RIU 为折射率单元)。

In this paper, we propose a Fresnel reflection-based optical fiber sensor system for remote refractive index measurement using the optical time domain reflectometry technique as an interrogation method. The surrounding refractive index from a long distance away can be measured easily by using this sensor system, which operates based on testing the Fresnel reflection intensity from the fiber-sample interface. This system is a simple configuration, which is easy to handle. Experimental results showed that the range of this measurement could reach about 100.8 km, and the refractive index sensitivities were from 38.71 dB/RIU to 304.89 dB/RIU in the refractive index (RI) range from 1.3486 to 1.4525.

文章对光纤拉曼放大器系统应用于NZ-DSF(非零色散位移光纤)中存在的泵浦与噪声之间的FWM(四波混频)现象进行了理论分析和实验证明。在理论分析中推断出第4束光出现的位置, 并且在实验中加以证明。由此基础上提出, 在光纤拉曼放大器系统中应用NZ-DSF时, 泵浦波长应当远离零色散位移点, 避免FWM效应的产生。

A brief review of recent progress in researches, productions and applications of full distributed fiber Raman photon sensors at China Jiliang University (CJLU) is presented. In order to improve the measurement distance, the accuracy, the space resolution, the ability of multi-parameter measurements, and the intelligence of full distributed fiber sensor systems, a new generation fiber sensor technology based on the optical fiber nonlinear scattering fusion principle is proposed. A series of new generation full distributed fiber sensors are investigated and designed, which consist of new generation ultra-long distance full distributed fiber Raman and Rayleigh scattering photon sensors integrated with a fiber Raman amplifier, auto-correction full distributed fiber Raman photon temperature sensors based on Raman correlation dual sources, full distributed fiber Raman photon temperature sensors based on a pulse coding source, full distributed fiber Raman photon temperature sensors using a fiber Raman wavelength shifter, a new type of Brillouin optical time domain analyzers (BOTDAs) integrated with a fiber Raman amplifier for replacing a fiber Brillouin amplifier, full distributed fiber Raman and Brillouin photon sensors integrated with a fiber Raman amplifier, and full distributed fiber Brillouin photon sensors integrated with a fiber Brillouin frequency shifter. The Internet of things is believed as one of candidates of the next technological revolution, which has driven hundreds of millions of class markets. Sensor networks are important components of the Internet of things. The full distributed optical fiber sensor network (Rayleigh, Raman, and Brillouin scattering) is a 3S (smart materials, smart structure, and smart skill) system, which is easy to construct smart fiber sensor networks. The distributed optical fiber sensor can be embedded in the power grids, railways, bridges, tunnels, roads, constructions, water supply systems, dams, oil and gas pipelines and other facilities, and can be integrated with wireless networks.

基于矢量衍射理论，计算了径向偏振光束在焦点处光强分布。在径向偏振光束的聚焦过程中，焦斑大小主要取决于视场边缘的光线。根据这一特点，设计了以视场角正切值为自变量的连续型相位滤波函数。利用非线性规化算法，以缩小焦平面上横向宽度为目标，在不同的斯特尔比的约束条件下，优化得到一组相位滤波参数。计算结果表明，径向偏振光束通过此种相位滤波器再聚焦后，在保持相同斯特尔比的条件下，可获得更小的聚焦光斑。

在背向抽运的光纤拉曼放大器(FRA)中,能够观察到级联的受激布里渊散射(SBS)。在SBS实验中，采用最大输出功率为3000 mW的三波长光纤拉曼激光器作为拉曼抽运源，25 km单模光纤(SMF)作为布里渊增益和拉曼增益介质，功率为3 dBm的外腔式激光器（ECL）作为布里渊抽运源。在实验中观察到的前、后向级联SBS的最高级数分别为156条和89条，前、后向SBS相邻级次光谱之间的频移分别为11 GHz和22 GHz，即它们波长间隔分别为0.085 nm和0.166 nm，光谱带宽分别为13.580 nm和14.812 nm。与前向传输相比，后向输出的平坦性要好。与单波长FRA相比，用三波长拉曼激光器作为抽运源更容易得到平坦性好和阶数更多的级联SBS。

研究和讨论了分布式光纤传感器系统的测温方法和原理, 介绍了国内外的研究概况、存在的问题和当前的研究趋势, 探索了新一代光纤非线性效应的光纤传感机理。提出了光纤非线性散射效应的融合原理, 研究和设计了一系列基于光纤拉曼与布里渊散射的分布式光纤传感器, 采用光纤色散与损耗光谱的自校正方法提高了系统的可靠性、空间分辨率和测温精度; 采用脉冲编码调制光源, 提高了系统的信噪比和测温精度。

对国内外已报道的强度解调型光纤布拉格光栅(FBG)传感器进行了综述,按解调方法将其归类为光栅匹配法、边缘滤波法、光栅啁啾法、激光匹配法和射频探测法。对各种方法的原理进行了介绍,对各自的优缺点等进行了评述,并对强度解调型FBG传感器的发展进行了展望。

介绍了一种应用于分布式光纤拉曼温度传感器的温度补偿电路，该温度补偿电路通过对雪崩光电二极管的反偏电压进行温度补偿来抵消环境温度对雪崩光电二极管的影响，从而大大降低了系统的温度漂移。采用该温度补偿电路的系统可在0～60 ℃的环境温度范围内将温漂引起的测量偏差控制在±0.1 ℃之内。和传统的恒温装置相比，采用温度补偿电路可有效降低系统的功耗和成本。