Multigigabit optical transmission experiment through a free-space simulator

Abstract

ABSTRACTA transmission experiment through a free-space laser transmission simulator for an optical intersatellite link is proposed and demonstrated. For multigigabit optical intensity modulation, adoption ofboth a direct current modulation of the laser diode and external optical intensity modulator are examined.Bit error rate (BER) characteristics, including the far-field pattern (FFP) of the optical antenna and beamcoupling loss, as well as beam pointing error fluctuation are clarified in assuming intersatellite distances.Design directions of the optical beam tracking system and high capacity optical transmission in the 0.83tm wavelength region, between optical intersatellite links, are clarified in this experiment. 1. INTRODUCTION An optical intersatellite link (ISL) can enable a small satellite to handle a large number of transmis-sions, to support human activity on earth as well as in space. For example, optical ISLs between low-earthorbit (LEO) satellites can become the infrastructure for mobile and personal communications on a globalscale[fl. It might be no exaggeration to say that, sooner or later, a multigigabit data highway through theuniverse will be required.ATR has been developing a transmitter[2I and a receiver as well as an optical antenna[31 for anoptical ISL. At the final stage of development, transmission tests that include these overall elements mustbe conducted under conditions that are as realistic as possible.This paper focuses on a transmission experiment in our free space laser transmission simulator[4I,using a transmitter and receiver designed for gigabit use, and an optical antenna. Many transmission ex-periments for optical ISLs have been reported[5I, however, to our best knowledge, no transmission experi-