Long-distance OTDR using photon counting and large detection gates at telecom wavelength

摘要

Photon-counting OTDRs are typically used in a mode with spatial resolutions in the centimeter range. Here we demonstrate that their sensitivity and dynamic range can be enlarged using lower resolutions. A 44-dB dynamic range was experimentally obtained at a wavelength of 1550 nm. This represents a 4-dB increase compared to state-of-the-art long-haul classical OTDRs having the same spatial resolution, and could even be extended to 6.5 dB when using a source with +13-dBm peak power. Furthermore we demonstrate an original solution to suppress perturbing dead-zones. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 6]