Sophia Magazine vol.1 / SUMMER 2015

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12minutes to make a design drawing, and whenever it failed, I had to start all over from scratch again. Those were my early research days at NTT.” Under the leadership of Professor Takahashi, however, the principle of the optical circuit, once considered impossible, was conrmed within only a few years, along with a roadmap planned in the latter half of the 1990s for its practical appli-cation. While he was conducting research and development, he was also faced with the task of marketing this technol-ogy overseas. Consequently, after a North American com-munications equipment manufacturer decided to adopt the technology, wavelength-division multiplexing devices all over the world started using the AWG from the year 2000. For this achievement, the professor received a Fellowship at the IEEE in 2014 and a Commendation for Science and Technology from the Minister of Education, Culture, Sports, Science and Technology in 2015. “As a researcher, there is nothing more gratifying than being recognized for research that is useful to global so-ciety,” said Professor Takahashi. “The Department of In-formation and Communication Sciences I belong to has a mathematics and biology faculty in addition to the faculty of communications and information. It is very satisfying for me to be able extend the information and communication research to other elds by working together with the faculty members of those different elds. Because the university is located in the metropolitan area, it is very easy for me to attend research conferences outside the university and collaborate with various corporations. Sophia University provides an extremely ideal environment for research and development.” Professor Takahashi asserted that he wants to work on re-search that is even more challenging than before in order to further improve optical transmission speed.chip called the optical waveguide. As a result of this world-rst technology, it is today possible to transmit 80 different wavelengths of light all at once. “Using these Arrayed-Waveguide Grating (AWG) wave-length lters, we have successfully increased the transmis-sion capacity of a single optical ber cable by approximately 100 times (1,000 gigabits per second) compared with the conventional speed.” Even though he has been successful in carrying out such epoch-making research and development, Profes-sor Takahashi has absolutely no affectations about his ac-complishments. He has been working on the development of the optical waveguide since the 1990s, when he was a researcher at Nippon Telegraph and Telephone Corporation (NTT), and he remembers his research work at that time as being basically smooth and going well. “I started research on the optical waveguide because my supervisor suggested it to me just after I started working at NTT. The only difculty I encountered was in programming the software for designing the optical path on my own. The optical waveguide itself has an edge of 6 micrometers and the wavelength of the light is 1.55 micrometers. So the level of precision required for designing an optical waveguide is approximately 0.01 micrometers. To write my own program for creating a design drawing for the optical waveguide, I had to write another program. Personal computer perfor-mance at that time was very slow, so it took more than 30 Several hundred extremely high-precision waveguides are printed using optical circuit technology on a silicon substrate that is only 2 by 3 square centimeters.Achievement of AWG Recognized inJapan and Around the WorldResearch