本文利用瑞利散射原理分析了脉冲信号和脉宽大于、小于回波时间的方波信号的回波信号波形,并利用数值模拟得到了其理论波形图。根据原理自主搭建了一套光纤光时域反射仪(Optic Time Domain Reflectometer,简称OTDR),用通信中通用的1550n...本文利用瑞利散射原理分析了脉冲信号和脉宽大于、小于回波时间的方波信号的回波信号波形,并利用数值模拟得到了其理论波形图。根据原理自主搭建了一套光纤光时域反射仪(Optic Time Domain Reflectometer,简称OTDR),用通信中通用的1550nm激光波长对样品光纤进行了实际测量,得到了与理论模拟完全一致的实测波形。通过对实测波形进行降噪处理得到了高精度的长度测量值和损耗测量值。长度测量的相对误差仅为0.0085%,与直接测量值比较,光纤传输损耗的相对误差为0.086%,理论与实验表明该OTDR系统完全可以与工程用的OTDR系统相媲美,在工程技术和教学研究中具有一定的应用前景。展开更多
Recently, FTTH （fiber to the home） is spreading rapidly, and communication technology has become an indispensable part in our lives. FTTH installers who build the infi＇astructure must correspond to the progress of ...Recently, FTTH （fiber to the home） is spreading rapidly, and communication technology has become an indispensable part in our lives. FTTH installers who build the infi＇astructure must correspond to the progress of technology while ensuring a high quality of installation, and it is struggling to its counterpart. The present study is undertaken in order to propose effective vocational ability development program for FTTH installers from the approach of their skill. They are information network cabling-related qualification system and competitions as the ability evaluation system. Then the author concludes that this program makes a contribution to improving their skill and maintaining the quality of the optical fiber network in analyzing some example of actual installation work and the measurement result of the OTDR（optical time domain reflect） meter.展开更多
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 surroundin...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 100.8km, 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.展开更多
We propose a fully distributed fusion system combining phase-sensitive optical time-domain reflectometry(Φ-OTDR) and OTDR for synchronous vibration and loss measurement by setting an ingenious frequency sweep rate(FS...We propose a fully distributed fusion system combining phase-sensitive optical time-domain reflectometry(Φ-OTDR) and OTDR for synchronous vibration and loss measurement by setting an ingenious frequency sweep rate(FSR) of the optical source. The relationships between FSR, probe pulse width and repeat period are given to balance the amplitude fluctuation of OTDR traces, the dead zone probability and the measurable frequency range of vibration events. In the experiment, we achieve synchronous vibration and loss measurement with FSR of 40 MHz/s, the proble pulse width of 100 ns and repeat rate of 0.4 ms. The fluctuation of OTDR trace is less than 0.45 dB when the signalto-noise ratio(SNR) is over 12 dB for a captured vibration event located at 9.1 km. The proposed method can be used for not only detection but also early warning of damage events in optical communication networks.展开更多
This article reviews my new optical fiber sensing （OFS） research activities in China for the last ten years at Chongqing University and University of Electronic Science and Technology of China, since I returned from...This article reviews my new optical fiber sensing （OFS） research activities in China for the last ten years at Chongqing University and University of Electronic Science and Technology of China, since I returned from UK in 1999. The research progress in long period fiber gratings （LPFGs）, distributed fiber sensing systems and microfiber sensors is introduced. For LPFGs, the processing method with high-frequency CO2 laser pulses types of LPFGs fabricated and the related applications for both optical sensing and optical communication are described. For distributed fiber sensing systems, the fiber-optic polarization optical time domain reflectometer （POTDR）, fiber-optic phase-sensitive optical time domain reflectometer （φ-OTDR） and Brillouin optical time-domain analyzer （BOTDA） are developed, respectively. For microfiber sensors, we mainly focus on the knot resonator and its application for sensing of the refractive index and acceleration, etc.展开更多
A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ...A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ℃-195 ℃ with a resolution of 0.12 ℃ and a linearity of 0.992 could be achieved for the multimode fiber （MMF） graded index with a length of 60mm. It was also demonstrated that two-point temperature measurement with two SMS fiber structures as temperature sensors could be made. The proposed temperature measurement system offered a high resolution and also benefited from a simple configuration with a capability of multi-point temperature measurement.展开更多
This work presented a demonstration of the potential for a fiber based cavity ring-down （CRD） using an optical time-domain reflectometer （OTDR）. The OTDR was used to send the impulses down into about 20km of a sta...This work presented a demonstration of the potential for a fiber based cavity ring-down （CRD） using an optical time-domain reflectometer （OTDR）. The OTDR was used to send the impulses down into about 20km of a standard single optical fiber, at the end of which the fiber cavity ring-down was placed. The OTDR measured no appreciable losses, so other CRDs multiplexed could be spliced in parallel along the same optical fiber. To demonstrate the behavior and sensitivity of the proposed configuration, a displacement sensor based on a fiber taper with a diameter of 50 μm was placed inside the fiber loop, and the induced losses were measured on the CRD signal -- a sensitivity of 11.8 ＋ 0.5 μs/mm was achieved. The dynamic range of the sensing head used in this configuration was about 2 mm. Finally, this work was also compared with different works published in the literature.展开更多
文摘本文利用瑞利散射原理分析了脉冲信号和脉宽大于、小于回波时间的方波信号的回波信号波形,并利用数值模拟得到了其理论波形图。根据原理自主搭建了一套光纤光时域反射仪(Optic Time Domain Reflectometer,简称OTDR),用通信中通用的1550nm激光波长对样品光纤进行了实际测量,得到了与理论模拟完全一致的实测波形。通过对实测波形进行降噪处理得到了高精度的长度测量值和损耗测量值。长度测量的相对误差仅为0.0085%,与直接测量值比较,光纤传输损耗的相对误差为0.086%,理论与实验表明该OTDR系统完全可以与工程用的OTDR系统相媲美,在工程技术和教学研究中具有一定的应用前景。
文摘Recently, FTTH （fiber to the home） is spreading rapidly, and communication technology has become an indispensable part in our lives. FTTH installers who build the infi＇astructure must correspond to the progress of technology while ensuring a high quality of installation, and it is struggling to its counterpart. The present study is undertaken in order to propose effective vocational ability development program for FTTH installers from the approach of their skill. They are information network cabling-related qualification system and competitions as the ability evaluation system. Then the author concludes that this program makes a contribution to improving their skill and maintaining the quality of the optical fiber network in analyzing some example of actual installation work and the measurement result of the OTDR（optical time domain reflect） meter.
文摘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 100.8km, 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.
基金supported by the National Natural Science Foundation of China(Nos.61405090,61307096 and 61540017)
文摘We propose a fully distributed fusion system combining phase-sensitive optical time-domain reflectometry(Φ-OTDR) and OTDR for synchronous vibration and loss measurement by setting an ingenious frequency sweep rate(FSR) of the optical source. The relationships between FSR, probe pulse width and repeat period are given to balance the amplitude fluctuation of OTDR traces, the dead zone probability and the measurable frequency range of vibration events. In the experiment, we achieve synchronous vibration and loss measurement with FSR of 40 MHz/s, the proble pulse width of 100 ns and repeat rate of 0.4 ms. The fluctuation of OTDR trace is less than 0.45 dB when the signalto-noise ratio(SNR) is over 12 dB for a captured vibration event located at 9.1 km. The proposed method can be used for not only detection but also early warning of damage events in optical communication networks.
文摘This article reviews my new optical fiber sensing （OFS） research activities in China for the last ten years at Chongqing University and University of Electronic Science and Technology of China, since I returned from UK in 1999. The research progress in long period fiber gratings （LPFGs）, distributed fiber sensing systems and microfiber sensors is introduced. For LPFGs, the processing method with high-frequency CO2 laser pulses types of LPFGs fabricated and the related applications for both optical sensing and optical communication are described. For distributed fiber sensing systems, the fiber-optic polarization optical time domain reflectometer （POTDR）, fiber-optic phase-sensitive optical time domain reflectometer （φ-OTDR） and Brillouin optical time-domain analyzer （BOTDA） are developed, respectively. For microfiber sensors, we mainly focus on the knot resonator and its application for sensing of the refractive index and acceleration, etc.
基金This work was supported Technology Research Grant Science Foundation. by Science and Indonesia Toray
文摘A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ℃-195 ℃ with a resolution of 0.12 ℃ and a linearity of 0.992 could be achieved for the multimode fiber （MMF） graded index with a length of 60mm. It was also demonstrated that two-point temperature measurement with two SMS fiber structures as temperature sensors could be made. The proposed temperature measurement system offered a high resolution and also benefited from a simple configuration with a capability of multi-point temperature measurement.
文摘This work presented a demonstration of the potential for a fiber based cavity ring-down （CRD） using an optical time-domain reflectometer （OTDR）. The OTDR was used to send the impulses down into about 20km of a standard single optical fiber, at the end of which the fiber cavity ring-down was placed. The OTDR measured no appreciable losses, so other CRDs multiplexed could be spliced in parallel along the same optical fiber. To demonstrate the behavior and sensitivity of the proposed configuration, a displacement sensor based on a fiber taper with a diameter of 50 μm was placed inside the fiber loop, and the induced losses were measured on the CRD signal -- a sensitivity of 11.8 ＋ 0.5 μs/mm was achieved. The dynamic range of the sensing head used in this configuration was about 2 mm. Finally, this work was also compared with different works published in the literature.
