中国激光, 2019, 46 (8): 0806003, 网络出版: 2019-08-13 复制并引用该论文  本文已被引 3 次  被引通知

图 & 表

图 1. 实验系统

Fig. 1. Experimental setup

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图 2. DFB频率啁啾测量系统

Fig. 2. Measurement system for DFB frequency chirp

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图 3. 不同参考光波长下的拍频图样。 (a)参考波长为1548.973 nm的拍频图样;(b)参考波长为1549.088 nm时的拍频图样

Fig. 3. Beat signals under different reference wavelengths. (a) Beat signal when reference wavelength λ=1548.973 nm; (b) beat signal when reference wavelength λ=1549.088 nm

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图 4. 内调制啁啾测量结果。(a)连续光的波长为1548.973 nm时的频率变化;(b)连续光波长为1549.088 nm时的频率变化;(c)经过拼接后获得的脉冲内频率变化

Fig. 4. Measurement results of internal modulation chirp. (a) Spectrogram of beat signal when continuous wavelength λ=1548.973 nm; (b) spectrogram of beat signal when continuous wavelength λ=1549.088 nm; (c) pulse frequency change after stitching

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图 5. 探测信号图样。(a)内调制直接探测型φ-OTDR系统探测波形;(b)传统直接探测型φ-OTDR系统探测波形

Fig. 5. Detection signal patterns. (a) Detected signal of internally modulated direct detection type φ-OTDR system; (b) detected signal of traditional direct detection type φ-OTDR system

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图 6. 两种系统的探测信号对比。(a)内调制直接探测型φ-OTDR系统的原始时域信号;(b)传统直接探测型φ-OTDR系统的原始时域信号;(c)内调制直接探测型φ-OTDR系统扰动位置处信号的一阶微分;(d)传统直接探测型φ-OTDR系统扰动位置处信号的一阶微分

Fig. 6. Comparison of detection signals of two systems. (a) Original time domain signal of internally modulated direct detection type φ-OTDR system; (b) original time domain signal of traditional direct detection type φ-OTDR system; (c) first-order differential of disturbance signal of internally modulated direct detection type φ-OTDR system; (d) first-order differential of disturbance signal of traditional direct detection type φ-OTDR system

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图 7. 传统直接探测型φ-OTDR系统扰动信号、内调制直接探测型φ-OTDR扰动信号和噪声信号的统计分布特征。插图为根据(4)式计算的,每10 min扰动位置z0处的SNR随时间的统计分布拟合

Fig. 7. Statistical distribution characteristics of disturbance signals of internally modulated direct detection type φ-OTDR system and traditional direct detection type φ-OTDR system and noise. Insert is fitting curve of SNR statistical distribution with time at disturbance position z0, and fitting curve is calculated according to equation (4) for every 10 minutes

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图 8. 双通道φ-OTDR、OTDR系统

Fig. 8. System with two channels of φ-OTDR and OTDR

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李鲁川, 卢斌, 王校, 梁嘉靖, 郑汉荣, 王照勇, 叶青, 方祖捷, 庞拂飞, 蔡海文. 基于内调制啁啾脉冲的高信噪比低成本直接探测型φ-OTDR系统[J]. 中国激光, 2019, 46(8): 0806003. Luchuan Li, Bin Lu, Xiao Wang, Jiajing Liang, Hanrong Zheng, Zhaoyong Wang, Qing Ye, Zujie Fang, Fufei Pang, Haiwen Cai. Internally Modulated Chirped Pulse Based Direct Detection Type φ-OTDR System with High Signal-to-Noise Ratio and Low Cost[J]. Chinese Journal of Lasers, 2019, 46(8): 0806003.