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Long-haul and high-resolution optical time domain reflectometry using superconducting nanowire single-photon detectors.

Zhao Q, Xia L, Wan C, Hu J, Jia T, Gu M, Zhang L, Kang L, Chen J, Zhang X, Wu P - Sci Rep (2015)

Bottom Line: In a 40-minute-long measurement, we obtained a dynamic range of 46.9 dB, corresponding to a maximum sensing distance of 246.8 km, at a two-point resolution of 0.1 km.The time for measuring fiber after 100 km was reduced to one minute, while the fiber end at 217 km was still distinguished well from noise.After reducing the pulse width to 100 ns, the experimental two-point resolution was improved to 20 m while the maximum sensing distance was 209.47 km.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093, China.

ABSTRACT
In classical optical time domain reflectometries (OTDRs), for sensing an 200-km-long fiber, the optical pulses launched are as wide as tens of microseconds to get enough signal-to-noise ratio, while it results in a two-point resolution of kilometers. To both reach long sensing distance and sub-kilometer resolution, we demonstrated a long-haul photon-counting OTDR using a superconducting nanowire single-photon detector. In a 40-minute-long measurement, we obtained a dynamic range of 46.9 dB, corresponding to a maximum sensing distance of 246.8 km, at a two-point resolution of 0.1 km. The time for measuring fiber after 100 km was reduced to one minute, while the fiber end at 217 km was still distinguished well from noise. After reducing the pulse width to 100 ns, the experimental two-point resolution was improved to 20 m while the maximum sensing distance was 209.47 km.

No MeSH data available.


Related in: MedlinePlus

Long-haul OTDR traces. (a) OTDR traces of six spools of fiber with a total length of 217 km. The six fiber spools and the noise floors are marked in different colors. The trace on top is from the first 30-minute-long measurement without attenuating optical pulses while the bottom one is from the second 10-minute-long measurement after attenuating optical pulses by 40 dB. The dashed lines are linear corrections of the saturated curves. (b) An enlarged view of the initial 100-km-long OTDR trace in the first measurement, where reflection peaks can be seen. The oscillation of the curve comes from the current reset dynamics of SNSPDs.
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f3: Long-haul OTDR traces. (a) OTDR traces of six spools of fiber with a total length of 217 km. The six fiber spools and the noise floors are marked in different colors. The trace on top is from the first 30-minute-long measurement without attenuating optical pulses while the bottom one is from the second 10-minute-long measurement after attenuating optical pulses by 40 dB. The dashed lines are linear corrections of the saturated curves. (b) An enlarged view of the initial 100-km-long OTDR trace in the first measurement, where reflection peaks can be seen. The oscillation of the curve comes from the current reset dynamics of SNSPDs.

Mentions: The ν-OTDR traces for the 217 km long fiber spools are shown in Fig. 3a. The width of optical pulses was tp = 1 μs and so was the time bin window. It took 30 minutes and 10 minutes for the first and the second measurement. As shown in Fig. 3b, although the optical pulses launched into the fiber in the first measurement were so strong that the trace saturated at the initial fiber, reflection peaks from the connections were visible. In other words, even though the attenuation property of the fiber was blinded, some information, such as location of connections or serious attenuations, could still be determined. To test the attenuation of the initial 100 km long fiber, we took a quick second measurement.


Long-haul and high-resolution optical time domain reflectometry using superconducting nanowire single-photon detectors.

Zhao Q, Xia L, Wan C, Hu J, Jia T, Gu M, Zhang L, Kang L, Chen J, Zhang X, Wu P - Sci Rep (2015)

Long-haul OTDR traces. (a) OTDR traces of six spools of fiber with a total length of 217 km. The six fiber spools and the noise floors are marked in different colors. The trace on top is from the first 30-minute-long measurement without attenuating optical pulses while the bottom one is from the second 10-minute-long measurement after attenuating optical pulses by 40 dB. The dashed lines are linear corrections of the saturated curves. (b) An enlarged view of the initial 100-km-long OTDR trace in the first measurement, where reflection peaks can be seen. The oscillation of the curve comes from the current reset dynamics of SNSPDs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4447072&req=5

f3: Long-haul OTDR traces. (a) OTDR traces of six spools of fiber with a total length of 217 km. The six fiber spools and the noise floors are marked in different colors. The trace on top is from the first 30-minute-long measurement without attenuating optical pulses while the bottom one is from the second 10-minute-long measurement after attenuating optical pulses by 40 dB. The dashed lines are linear corrections of the saturated curves. (b) An enlarged view of the initial 100-km-long OTDR trace in the first measurement, where reflection peaks can be seen. The oscillation of the curve comes from the current reset dynamics of SNSPDs.
Mentions: The ν-OTDR traces for the 217 km long fiber spools are shown in Fig. 3a. The width of optical pulses was tp = 1 μs and so was the time bin window. It took 30 minutes and 10 minutes for the first and the second measurement. As shown in Fig. 3b, although the optical pulses launched into the fiber in the first measurement were so strong that the trace saturated at the initial fiber, reflection peaks from the connections were visible. In other words, even though the attenuation property of the fiber was blinded, some information, such as location of connections or serious attenuations, could still be determined. To test the attenuation of the initial 100 km long fiber, we took a quick second measurement.

Bottom Line: In a 40-minute-long measurement, we obtained a dynamic range of 46.9 dB, corresponding to a maximum sensing distance of 246.8 km, at a two-point resolution of 0.1 km.The time for measuring fiber after 100 km was reduced to one minute, while the fiber end at 217 km was still distinguished well from noise.After reducing the pulse width to 100 ns, the experimental two-point resolution was improved to 20 m while the maximum sensing distance was 209.47 km.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093, China.

ABSTRACT
In classical optical time domain reflectometries (OTDRs), for sensing an 200-km-long fiber, the optical pulses launched are as wide as tens of microseconds to get enough signal-to-noise ratio, while it results in a two-point resolution of kilometers. To both reach long sensing distance and sub-kilometer resolution, we demonstrated a long-haul photon-counting OTDR using a superconducting nanowire single-photon detector. In a 40-minute-long measurement, we obtained a dynamic range of 46.9 dB, corresponding to a maximum sensing distance of 246.8 km, at a two-point resolution of 0.1 km. The time for measuring fiber after 100 km was reduced to one minute, while the fiber end at 217 km was still distinguished well from noise. After reducing the pulse width to 100 ns, the experimental two-point resolution was improved to 20 m while the maximum sensing distance was 209.47 km.

No MeSH data available.


Related in: MedlinePlus