The 1st International Conference on Optical and Terahertz Communications and Future Networks (OTCN 2025) will be held from September 26-28, 2025, in Tokyo, Japan. As a valuable academic platform, OTCN 2025 aims to bring together researchers, engineers, and industry professionals to explore cutting-edge developments in optical and terahertz communications, as well as the evolution of future network technologies. We warmly invite you to submit original research papers and share novel insights. Join us in Tokyo to exchange ideas, foster collaborations, and advance innovations shaping the future of communication networks.