1 天津大学精密仪器与光电子工程学院，天津 300072
2 齐鲁工业大学（山东省科学院）激光研究所，山东 济南 250014
3 山东建筑大学理学院，山东 济南 250101
地震检波器是石油勘探中必不可少的工具，主要被用于地震波采集以获取地层信息，进而实现油藏勘察以及压裂采油技术的监控。研究了分布式光纤声波传感（DAS）系统及其在石油物探中的应用，深入分析了DAS技术的干涉式解调原理、算法和参数测试。此外，还进行了地面物探实验，通过外场实验获取了大量地震波信息，绘制出了清晰的地震剖面图，并对DAS的性能和测试数据进行了详细分析。
光纤光学 光纤传感 石油物探 分布式声波传感器 检波器 激光与光电子学进展
2022, 59(3): 0306006
1 山东建筑大学理学院, 山东 济南 250101
2 山东省科学院激光研究所, 山东 济南 250103
介绍了一种基于分布反馈光纤激光器的超窄线宽布里渊光纤激光器。采用布里渊环形腔结构,以分布式反馈光纤激光器作为布里渊泵浦光源,以输出波长为980nm的半导体激光器作为腔内掺铒激光放大的泵浦光源,实现了超窄线宽的布里渊激光输出。布里渊环形腔腔长为10 m,加偏振控制后可获得单频布里渊激光输出。为保证激光器的单纵模输出,分布反馈光纤激光器和半导体激光器泵浦光源功率应分别不低于20 mW和50 mW。泵浦光源输出功率最大为250 mW时,最终布里渊激光输出功率超过15 mW,线宽可小于100 Hz。
光纤激光器 超窄线宽 分布式反馈 布里渊光纤激光器 激光与光电子学进展
2020, 57(7): 071401
Author Affiliations
Abstract
1 School of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China
2 Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
3 School of Electrical Engineering & Telecommunications, University of New South Wales, NSW 2052, Australia
We propose a new non-intrusive flow measurement method using the distributed feedback fiber laser (DFB-FL) as a sensor to monitor flow in the pipe. The relationship between the wavelength of the DFB-FL and the liquid flow rate in the pipeline is derived. Under the guidance of this theory, the design and test of the flow sensor is completed. The response curve is relatively flat in the frequency range of 10 Hz to 500 Hz, and the response of the flow sensor has high linearity. The flow from 0.6 m3/h to 25.5 m3/h is accurately measured under the energy analysis method in different frequency intervals. A minimum flow rate of 0.046 m/s is achieved. The experimental results demonstrate the feasibility of the new non-intrusive flow measurement method based on the DFB-FL and accurate measurement of small flow rates.
DFB-FL flow non-intrusive measurement energy analysis frequency interval Chinese Optics Letters
2020, 18(2): 021204
Author Affiliations
Abstract
Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250103, China
A fiber Bragg grating (FBG) and Fabry–Perot (FP) cavity cascaded fiber sensing system was manufactured for temperature and pressure sensing. Temperature sensing as high as 175°C was performed by an FBG for the linear variation of an FBG wavelength with temperature. After the temperature was sensed, the demodulation system can find the original FP cavity length and its pressure and cavity length correlation coefficient; thus, the ambient pressure would be calculated. The sensing pressure can be as high as 100 MPa with a repeatability of 1/10,000 and high stability. This kind of fiber sensor has been used in the Shengli Oil Field.
060.2370 Fiber optics sensors 060.3735 Fiber Bragg gratings 050.2230 Fabry-Perot Chinese Optics Letters
2019, 17(4): 040603
Author Affiliations
Abstract
1 Shandong Key Laboratory of Optical Fiber Sensing Technologies, Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
2 School of Electrical Engineering and Telecommunications, The University of New South Wales, NSW 2052, Australia
3 College of Precision Instrument and Opto-Electronics Engineering and Key Laboratory of Opto-Electronics Information and Technical Science, Ministry of Education, Tianjin University, Tianjin 300072, China
We present a high-sensitivity fiber Bragg grating (FBG)-based microphone with a flat response and static pressure equalization. A very high dynamic sensitivity of the microphone is achieved by a pressure sensing structure based on a carbon fiber diaphragm. Static pressure equalization is realized by a balance structure with a capillary glass tube. The resonances of the sensor are suppressed by air damping structures, and a broadened flat response is achieved. An acoustic-solid interaction model was used to analyze the response characteristics of the microphone. An experimental prototype was produced and tested, and the results are well consistent with the design. The tested sensitivity was 10 dB re 1 pm/Pa from 10 Hz to 2.5 kHz with a fluctuation of less than ±1.5 dB. Combined with the phase-generated-carrier-based coherent detection scheme, the microphone can achieve a sound resolution of the milli-pascal level. The static pressure sensitivity is measured to be 0.27 pm/atm, which is 100 dB lower than the dynamic sensitivity.
060.2370 Fiber optics sensors Chinese Optics Letters
2019, 17(1): 010601
Author Affiliations
Abstract
1 School of Science, Shandong Jianzhu University, Jinan 250101, China
2 Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
Abstract: A π phase-shifted fiber Bragg grating theoretical model is established, and the effects of an asymmetric and symmetrical perturbation field on a phase-shifted fiber Bragg grating are investigated in this paper. The trends of wavelength shifting caused by effective refraction index of phase shift grating in symmetric and asymmetric acoustic field are investigated in detail. Then, the fiber laser acoustic sensors packaged in asymmetric and symmetrical structures are designed and tested, respectively. The results show that the acoustic response of the wavelength of the distributed feedback (DFB) fiber laser (FL) in an asymmetric packaging structure is much more sensitive than in that in the symmetrical structure. The sensor packaged in the asymmetrical structure has a better low frequency (0 Hz-500 Hz) performance and a higher sensitivity than that in the symmetrical structure, and the sensitivity is improved about 15 dB in average and 32.7 dB in maximum. It provides a new method to improve the sensitivity of the fiber acoustic sensor.
Fiber acoustic sensor phase-shifted fiber Bragg grating asymmetric perturbation Photonic Sensors
2018, 8(4): 04351
1 齐鲁工业大学(山东省科学院), 山东省科学院激光研究所, 山东 济南 250014
2 新南威尔士大学 电气工程与电信学院, 新南威尔士 2052
提出了应用于周界安防的基于后向瑞利散射光空间差分干涉的光纤分布式振动传感监测方案。环境振动信号引起传感光纤的相位变化, 含有相位信息的后向瑞利散射信号注入到非平衡迈克尔逊干涉仪, 实现了后向瑞利散射信号的空间差分干涉, 光纤分布式振动传感监测完成相位信号的解调, 提高了系统的灵敏度。该系统能够实时监测入侵者的行走路线和速率以及模拟挖掘的距离的判断, 实现了15 dB的信噪比以及35 m的探测距离。
分布式振动传感 周界安防 干涉仪 空间差分 distributed vibration sensing perimeter security interferometer space difference 红外与激光工程
2018, 47(5): 0522001
Author Affiliations
Abstract
Shandong Key Laboratory of Optical Fiber Sensing & Techonology, Laser Institute of Shandong Academy of Science,China, Jinan, 250014, China
A short cavity distributed feedback (DFB) fiber laser is used for low frequency acoustic signal detection. Three DFB fiber lasers with different central wavelengths are chained together to make three-element vector hydrophone with proper sensitivity enhancement design, which has extensive and significant applications to underwater acoustic monitoring for the national defense, oil, gas exploration, and so on. By wavelength-phase demodulation, the lasing wavelength changes under different frequency signals can be interpreted, and the sensitivity is tested about 33 dB re pm/g. The frequency response range is rather flat from 5 Hz to 300 Hz.sensitivity
Short cavity distributed feedback fiber laser vector hydrophone frequency response phase noise Photonic Sensors
2017, 7(4): 325
Author Affiliations
Abstract
1 State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
2 Jinan Research Center, Laser Institute of Shandong Academy of Sciences, Jinan, 250014, China
3 School of Electronic Engineering and Telecommunication, University of New South Wales, Sydney, 2052, Austrilia
Fiber laser hydrophones have got widespread concerns due to the unique advantages and broad application prospects. In this paper, the research results of the eight-element multiplexed fiber laser acoustic pressure array and the interrogation system are introduced, containing low-noise distributed feedback fiber laser (DFB-FL) fabrication, sensitivity enhancement packaging, and interferometric signal demodulation. The frequency response range of the system is 10 Hz-10 kHz, the laser frequency acoustic pressure sensitivity reaches 115 dB re Hz/Pa, and the equivalent noise acoustic pressure is less than 60μPa Hz1/2. The dynamic range of the system is greater than 120 dB.
Fiber laser hydrophone Fiber laser hydrophone DFB-FL DFB-FL packaging sensitization packaging sensitization eight-element multiplex eight-element multiplex interferometric demodulation interferometric demodulation Photonic Sensors
2017, 7(3): 253
介绍了一种光纤光栅应变传感系统在船舶结构监测中的应用。首先设计了贴片式的光纤光栅应变传感器，采用无胶化封装，具有良好的线性和重复性。然后搭建了基于非平衡MZ干涉仪的PGC解调系统，实现了船体应变信号的高精度实时解调。最后介绍了传感器的施工工艺和流程，并对传感系统采集到的结构应变数据进行了分析。研究成果对光纤光栅应变传感系统在船舶结构监测中的推广应用具有工程指导意义。
光纤光栅 应变 船舶 结构监测 FBG strain ship structure monitoring
