报道了一种高性能大孔径分布式光纤水听拖曳阵列，其总长度为150 m，声学传感段长度为100 m，具有192个传感单元，采用单根光纤离散增敏制备而成，无需其他分离器件。传感基元通过驻波桶标定，在20~1000 Hz，平均声压灵敏度达到-127.44 dB（re rad/μPa）。阵列同时装配了自研的姿态感知模块，可实现拖曳过程的实时姿态获取。针对所研制的大规模分布式光纤水听拖曳阵列，开展了湖试综合测试，6 kn拖速下阵列声学段的倾角仅为7.8°，将192个传感单元数据波束合成后得到了16.87 dB的空间增益，传感器表现出了优异的综合性能。该高性能大规模分布式光纤水听拖曳阵列为光纤水听器发展提供了一条全新的技术路线，有力推动了基于DAS的“第三代声呐技术”的发展。

A length-matched micro Fabry-Perot (FP) interferometer is proposed for strain measurement under irradiation environment. Theoretical simulation shows that a well length-matched FP sensor can achieve a very low drift of the cavity length and strain sensitivity in irradiation environment. In experiment, such an FP cavity is realized by laser micromachining. It shows a low cavity length drift of -0.037 μm and a strain sensitivity deviation of 0.52%, respectively, under gamma irradiation. Meanwhile, the intensity of interference fringes is also stable. As a result, such a length-matched FP cavity is a very promising candidate for strain sensing in radiative environments.

The sensing characteristics of irradiated fiber Bragg gratings (FBGs) and Fabry-Perot interferometers (FPIs) were investigated under a 2 MGy dose of gamma radiation. The study found that the pressure sensitivity of FP sensors after irradiation was stable, while the temperature sensitivity of FBG sensors was unstable, and both wavelengths displayed a shift. These findings offer the possibility for the application of FP pressure sensors in the gamma radiation environments, and FBG sensors require further research to be suitable for application in the nuclear radiation environments.

This paper reviews a wide variety of fiber-optic microstructure (FOM) sensors, such as fiber Bragg grating (FBG) sensors, long-period fiber grating (LPFG) sensors, Fabry-Perot interferometer (FPI) sensors, Mach-Zehnder interferometer (MZI) sensors, Michelson interferometer (MI) sensors, and Sagnac interferometer (SI) sensors. Each FOM sensor has been introduced in the terms of structure types, fabrication methods, and their sensing applications. In addition, the sensing characteristics of different structures under the same type of FOM sensor are compared, and the sensing characteristics of the all FOM sensors, including advantages, disadvantages, and main sensing parameters, are summarized. We also discuss the future development of FOM sensors.

Phase-sensitive optical time domain reflectometry (Ф-OTDR) is an effective way to detect vibrations and acoustic waves with high sensitivity, by interrogating coherent Rayleigh backscattering light in sensing fiber. In particular, fiber-optic distributed acoustic sensing (DAS) based on the Ф-OTDR with phase demodulation has been extensively studied and widely used in intrusion detection, borehole seismic acquisition, structure health monitoring, etc., in recent years, with superior advantages such as long sensing range, fast response speed, wide sensing bandwidth, low operation cost and long service lifetime. Significant advances in research and development (R&D) of Ф-OTDR have been made since 2014. In this review, we present a historical review of Ф-OTDR and then summarize the recent progress of Ф-OTDR in the Fiber Optics Research Center (FORC) at University of Electronic Science and Technology of China (UESTC), which is the first group to carry out R&D of Ф-OTDR and invent ultra-sensitive DAS (uDAS) seismometer in China which is elected as one of the ten most significant technology advances of PetroChina in 2019. It can be seen that the Ф-OTDR/DAS technology is currently under its rapid development stage and would reach its climax in the next 5 years.

本文提出了一种能够与胃镜相匹配的光纤拉曼光谱系统和积分能量比相结合来快速诊断胃癌的方法。首先, 采用光纤拉曼光谱系统对来自 17例胃正常粘膜, 12例胃腺癌粘膜的活检组织进行拉曼光谱检测 (激发光波长 785 nm, 功率 50 mW, CCD温度-80 ℃, 采集时间 1 s)。然后, 采用降低基线、快速傅里叶转化 (FFT)平滑对拉曼原始光谱进行预处理。最后, 根据拉曼谱图特征, 分析了拉曼特征峰的归属, 比较了胃正常和胃腺癌粘膜的拉曼光谱差异和连续频带内(1500 cm-1～1700 cm-1)和非连续频带 (1100 cm-1～1200 cm-1)积分能量比。结果表明, 胃腺癌粘膜位于 1002 cm-1、 1073 cm-1、1450 cm-1、1655 cm-1归属于苯丙氨酸和蛋白质的拉曼峰强度比正常粘膜相对增高, 胃正常和胃腺癌粘膜在连续频带内和非连续频带积分能量差异明显(独立样本 t检验, P<0.05), 并以积分能量的比值来作为诊断指标, 获得的准确度达到 97.5%～98.5%, 敏感度达到 91.7%和特异度达到 100.0%。

A fiber-optic Raman spectrum sensor system is used for the fast diagnosis of esophageal cancer during clinical endoscopic examination. The system contains a 785 nm exciting laser, a Raman fiber-optic probe with 7 large core fibers and a focus lens, and a highly sensitive spectrum meter. The Raman spectrum of the tissue could be obtained within 1 second by using such a system. A signal baseline removal and denoising technology is used to improve the signal quality. A novel signal feature extraction method for differentiating the normal and esophageal cancer tissues is proposed, based on the differences in half-height width (HHW) in 1200 cm^-1 to 1400 cm^-1 frequency band and the ratios of the spectral integral energy between 1600 cm^-1 - 1700 cm^-1 and 1500 cm^-1 - 1600 cm^-1 band. It shows a high specificity and effectivity for the diagnosis of esophageal cancer.

应用包含探测光、布里渊泵浦光及拉曼泵浦光相互作用理论模型，数值分析了基于拉曼放大的长距离布里渊光时域分析仪非局域化特性。结果表明：非局域化随探测光及拉曼泵浦功率增加而恶化；通过频分复用(将具有不同布里渊频移的光纤拼接)及时分复用技术(同时对布里渊泵浦及探测光进行脉冲调制)，可有效缩短布里渊泵浦与探测光的作用距离，达到较理想的抑制非局域效应结果。based on Raman amplification

为了提高微光纤压力传感器的制作效率，采用157 nm激光加工的自封闭式法布里珀罗腔，形成在线式全光纤压力传感器，包括微腔和一截短的单模光纤。跟踪压力传感器相位的变化可以获得压力大小。在0~60 MPa的测量范围内，灵敏度达到0.01 rad/MPa，长期稳定性达到±0.04 MPa。所做的10个传感器样品，在60 MPa的测量范围内，灵敏度的冗余度达到±5%，可以规模化制造。这种传感器有望在航空航天、汽车工业和井下监测等领域发挥作用。

By using a graded-index multimode fiber (GI-MMF) with a relatively flat index profile and high refractive index of the fiber core, a microextrinsic fiber-optic Fabry?P′erot interferometric (MEFPI) strain sensor is fabricated through chemical etching and fusion splicing. Higher reflectance of the microcavity is obtained due to the less-curved inner wall in the center of the fiber core after etching and higher index contrast between the GI-MMF core and air. The maximum reflection of the sensor is enhanced 12 dB than that obtained by etching of the Er- or B-doped fibers. High fringe contrast of 22 dB is obtained. The strain and temperature responses of the MEFPI sensors are investigated in this experiment. Good linearity and high sensitivity are achieved, with wavelength-strain and wavelength-temperature sensitivities of 7.82 pm/\mu \varepsilon and 5.01 pm/?C, respectively.