Design and Evaluation of Fiber Direct Coupling Optical Antennas for Next Generation Optical Wireless Communication Systems

It is anticipated that compact optical antennas with an advanced fine optical tracking system will be used for the ultra-fast laser communication system in the next generation. Such laser communication systems will be used not only for the space communications but also the terrestrial long-distance network. In this paper, we discuss demand specifications of optical antennas considering phenomena such as the scintillation which occurs by atmospheric turbulence. And then we explain optics design and the design results to satisfy demand specifications. We also mention the fine tracking mechanism using the fine pointing mirror (FPM) and the feedback of the signal's incident angle detection by the quadrant detector (QD) for the antenna. The influences of fluctuation of laser beam angle-of-arrival (AOA) are reduced effectively. We mention the following research studies of the two optical wireless communication systems such as next generation free-space optical communication (NG-FSO) system and radio on FSO (RoFSO) system.