Optical time domain reflectometry in a single-mode fiber

Abstract

This paper describes the theoretical and experimental study of an optical time domain reflectometry (OTDR) in a single-mode fiber. The maximum measurable distance by the OTDR is theoretically studied. In the experiment, the cylindrical lens attached to the laser diode, the low-loss and low-crosstalk directional coupler, and the digital averaging technique combined enabled us to measure a break in a single-mode fiber up to 17 km in length. This paper also describes the application of the OTDR to loss measurement of a single-mode fiber.