Dr. Takahashi joined KDD R&D Laboratories Inc. (currently KDDI Research, Inc.) in 2000. He has worked in advanced optical fiber transmission technologies, especially for highly spectrally efficient transmission system with digital coherent technologies and high capacity system using multicore fiber. From late 2012 to present, he is a member of the Submarine Cable Planning and Engineering Section in Global Network Engineering and Operations Center of KDDI Corporation. He is in charge of a technical side of procurement and upgrade works for submarine cable systems as Manager. He has been involved in some cable systems such as APCN2, Unity, RJCN and FASTER, etc. From 2016, he also has an assignment at Photonic Transport Network Laboratory of KDDI Research, Inc. as R&D Manager for realizing the future technologies of high-capacity and long-distance optical fiber transmission systems.