Innovative tracking system for next generation FSO systems under massive earthquakes

FSO (Free Space Optical) communication system is a wireless communication system using a transmission link with the optical beam in free space, and it is expected to provide the communication between buildings, and areas where the placement of optical fiber is difficult. Furthermore, it is applied to the line in a large temporary disaster are expected to FSO. In addition, FSO can be applied as a fiber backup when the disaster occurred. However, since the light beam has high directivity in free space link, the shock and vibration due to environmental changes, will lead to large misalignment between the transmitting and receiving antennas. Therefore, their impact on the stability of the FSO communication system should be investigated. In this paper, we describe the results of the basic measurement data obtained at the Great East Japan Earthquake that occurred in March 2011. We investigate the impact of the earthquake on the tracking system technology for FSO that we have developed. Furthermore, we show the effectiveness of the proposed error correction for reducing the impact of earthquakes on the communication link.