It is our great pleasure to welcome you all to the 21st Optoelectronics and Communications Conference (OECC), which will take place in Niigata, Japan, from July 3-7, 2016. Held annually in the Pacific Rim region, OECC has a long tradition and is a leading international conference for researchers and engineers working in the fields of optoelectronics, fiber transmission, and photonic network systems. It has provided a valuable international forum to present and discuss R&D progress in these areas. OECC 2016 will be held jointly with Photonics in Switching 2016. This joint conference offers a great opportunity to seek out and explore a wide variety of R&D topics from basic research to system technologies. To a very large extent the success of OECC will depend on your contributions and active participation. We encourage you to attend the conference and submit your most recent research results. On behalf of the Organizing Committee, we would like to convey a hearty welcome to all of you who will participate in OECC2016 and wish you an enjoyable stay in Niigata.