Environmental Sensing Using Commodity Optical Transceivers: Laboratory and Field Studies

The widespread deployment of communication network optical fiber and communication systems offers compelling opportunities for sensing that can augment traditional geophone arrays and other fiber-based sensing methods. The immediate challenges to realizing these opportunities are determining <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(i)</i> how systems that already measure characteristics of optical signals can be adapted for sensing applications and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(ii)</i> the sensitivity of signals available from these systems to a range of environmental effects. In this paper, we use an optical transceiver widely deployed in network communications to assess how optical fiber strains are revealed in polarization transience measurements. We begin by evaluating the level of sensitivity to optical fiber strain in controlled laboratory tests. We then deploy our sensing system in the field to assess its efficacy for environmental sensing. We characterize the specific geometry and coupling of the fiber runs and report on the range and scope of capabilities. Our results highlight the potential for environmental sensing with optical fiber and communications network hardware and emphasize the necessary metrics reporting and cable installation specifications that are beneficial for monitoring applications.