An Extremely Efficient Active Multiplexing Technique for Large Optical Sensor Networks

To meet the requirements of a large sensor network for aircraft structure monitoring, Physical Optics Corporation (POC) proposes a novel active multiplexed fiber Bragg grating (FBG) sensor network for strain, temperature, and vibration monitoring. The active sensor addressing uses a super flourescence regenerator whose modulation period matches the round trip time of the addressed sensor's optical loop. Thus, the light energy is always concentrated on the addressed sensor. The sensor network energy efficiency is 10(4) to 10(5) times higher than that of conventional passive multiplexing techinques, resulting in a very high signal to noise ratio and low power consumption. Only such active addressing technique can make it possible to incorporate a large number of sensors in a network, while maintaining extremely low cross talk and high dynamic range. Using the proposed multiplexed FBG sensor network, combined with neural network data analysis techniques, the status of the aircraft structure can be reliably and promptly reported. The major effort in Phase I will be to demonstrate the feasibility and practicality of the active multiplexing technique, the key technique in the network. Anticipated Benefits: The proposed sensor network can find application in the aerospace industry, in monitoring of civil buildings, dams, electrical generators, gas or oil pipes, and high speed trains. The potential commercial market for the proposed sensor network is very large.