Tomoko NAKAYAMA^1*, Yoshihisa TAKAYAMA², Chiemi FUJIKAWA¹, Eriko WATANABE³, and Kashiko KODATE⁴

¹Department of Optical and Imaging Science & Technology, School of Engineering, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan
²Wireless Network Research Institute, National Institute of Information and Communications Technology, Koganei, Tokyo 184-8795, Japan
³Center for Frontier Science and Engineering, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
⁴Professor Emeritus, Japan Women's University, Bunkyo, Tokyo 112-8681, Japan

(Received March 31, 2014; Accepted May 29, 2014)

In recent years, there has been considerable interest in satellite–ground laser communication due to an increase in the quantity of data exchanged between satellites and the ground. However, improving the quality of this data communication is necessary as laser communication is vulnerable to air fluctuation. We first verify the spatial and temporal averaging effects using light beam intensity images acquired from middle-range transmission experiments between two ground positions and the superposition of these images using simulations. Based on these results, we propose a compact and lightweight optical duplicate system as a multi-beam generation device with which it is easy to apply the spatial averaging effect. Although an optical duplicate system is already used for optical correlation operations, we present optimum design solutions, design a compact optical duplicate system for satellite–ground laser communications, and demonstrate the efficacy of this system using simulations.

Key words: satellite–ground laser communication, optical duplicate system, air fluctuation, multi-beam generation, spatial averaging effect, temporal averaging effect

^*E-mail address: tomoko.nakayama0102@gmail.com