Power-over-fiber technique based sensing system for internet of things

Internet Of Things (IOT) drives a significant demand in the extent and type of sensing technology and equipment. Sensors, control electronics and transmission units in such sensing systems will all need to be powered. How-ever, in a strong electromagnetic radiation area and other extreme environments, the electromagnetic inter-ference (EMI) is the key issue for power supply methods. A novel power supply method, which might overcome this issue, is the power-over-fiber (POF) technique. In this technique, the optical energy out of a high power laser is transmitted via a fiber and then converted into the elec-trical energy by a photovoltaic power converter (PPC) on the other fiber end. As a fiber is used instead of electric power cables, the delivery of the power is inherently immune to electromagnetic radiation. Recently, we have built up an optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we have de-veloped a fiber-wireless sensor system based on the POF technique, to offer a flexible distributed sensing ability over a middle distance. In the demonstration system, a 2km away remote unit is optically powered and transmits back the sensing information, which is collected by a wireless sensor network (WSN) within a 50m range.