Influence of Laser Linewidth on Phase-OTDR System Based on Heterodyne Detection

被引：32

作者：

Li, Jiong ^{[1
,2
,3
,4
]}

Zhang, Zhitao ^{[1
,2
,3
,4
]}

Gan, Jiulin ^{[1
,2
,3
,4
]}

Zhang, Zhishen ^{[1
,2
,3
,4
]}

Heng, Xiaobao ^{[1
,2
,3
,4
]}

Zhou, Kaijun ^{[1
,2
,3
,4
]}

Zhao, Hua ^{[1
,2
,3
,4
]}

Xu, Shanhui ^{[1
,2
,3
,4
]}

Yang, Zhongmin ^{[1
,2
,3
,4
]}

机构：

[1] South China Univ Technol, Key Lab Luminescent Mat & Devices, Guangzhou 510640, Guangdong, Peoples R China

[2] South China Univ Technol, Inst Opt Commun Mat, Guangzhou 510640, Guangdong, Peoples R China

[3] Special Glass Fiber & Device Engn Technol Res & D, Guangzhou 510640, Guangdong, Peoples R China

[4] Guangdong Prov Key Lab Fiber Laser Mat & Appl Tec, Guangzhou 510640, Guangdong, Peoples R China

来源：

JOURNAL OF LIGHTWAVE TECHNOLOGY | 2019年 / 37卷 / 11期

基金：

国家重点研发计划;

关键词：

Applications; linewidth; optical fiber sensors; sensor system; strain; PHI-OTDR;

D O I：

10.1109/JLT.2018.2886461

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

A theoretical analysis of the influence of laser's linewidth on phase-OTDR sensing system is proposed and corresponding experiment is demonstrated. The linewidth factor of laser source is introduced into the signal expressions of phase-OTDR system under the nonquasi monochromatic light condition. The effect of linewidth can be transformed into an exponential decay item of the signal. Even if the sensing range is always smaller than the coherent length of the laser source, the detection SNR will decrease as the linewidth increases. A Phase-OTDR strain detection experiment with linewidth controllable laser is performed to verify the derived theoretical analysis result. The result shows that when linewidth increases from 2 kHz to 1 MHz, the detection SNR of the same vibration signal will decrease 4.3 dB. In order to select the appropriate laser source for phase-OTDR system, the coherent length and influence of linewidth ought to be taken into account to ensure the detection performance of the system.

引用

页码：2641 / 2647

页数：7

共 17 条

[1] Recent Development in the Distributed Fiber Optic Acoustic and Ultrasonic Detection [J].