Dispersion independent long-haul photon-counting optical time-domain reflectometry

Abstract

Photon counting optical time-domain reflectometry (PC-OTDR) based on the single photon detection is an effective scheme to attain the high spatial resolution for optical fiber fault monitoring. Currently, due to the spatial resolution of PC-OTDR is proportional to the pulse width of a laser beam, short laser pulses are essential for the high spatial resolution. However, short laser pulses have a large bandwidth, which would be widened by the dispersion of fiber, thereby causing inevitable deterioration in spatial resolution, especially for longhaul fiber links. In this letter, we propose a scheme of dispersion independent PC-OTDR based on an infinite backscatter technique. Our experimental results -with more than 50 km long fiber -show that the spatial resolution of the PC-OTDR system is independent with the total dispersion of the fiber under test. Our method provides an avenue for developing the long-haul PC-OTDR with high performance.

GHz photon-number resolving detection with high detection efficiency and low noise by ultra-narrowband interference circuits

“…In recent years, single-photon detection (SPD) techniques have been widely used for weak light detection in the fields such as quantum information (quantum computation [1] and quantum communication [2] ), optical time-domain reflectometer [3,4] , fluorescence measurements [5,6] and laser ranging [7,8] . These applications often demand stringent performance requirements for single-photon detectors.…”

Photon-counting optical time-domain reflectometry based on free-running single-photon avalanche detector

“…The SPAD is divided into two main types, the gated mode and free-running mode. The gated mode detector has a comparably lower afterpulse probability, which improves the performance of ν-OTDR, thus, most of the single-photon detectors in ν-OTDR operate in the gated mode [9][10][11][12]. However, reflected photons cannot be detected outside the gating time of the detector.…”

A Photon-Counting Optical Time-Domain Reflectometry Based Optical Fiber Temperature Sensor System

“…There are many single photon detection technologies have been applied to the PC-OTDR system. Superconducting nanowire single photon detector (SNSPD) greatly improves the performance of PC-OTDR in [7]- [11]. However, SNSPD requires liquid nitrogen for refrigeration, which is large in volume and expensive in price.…”