The research on optical communication in DOP includes optical interconnection, silicon photonics, thin film filter, integrated optics and integrated optical fiber system. In the near future, the connection between computers and their peripherals will highly rely on optical communication. Therefore, optical interconnect is one of the most important research topics. Moreover, the integrated circuits inside future computers will also utilizes the optical interconnect technology to pass the signal and information. Since integrated circuits are silicon-based components, silicon photonics is also essential. Prof. M. L. Wu in DOP has supervised a company which provides the high speed optical communication system to support international network companies for next generation internet. DOP devotes in using various materials such as silicon, LiNbO3, polymer… etc. to develop traditional waveguide, 45 degree Si mirror coupler, modulators, directional coupler, hollow waveguide… etc. The thin film center lead by Prof. C.C. Lee has the capability on designing and manufacturing various commercial thin film filters. DOP also has the integration technology on optical emission and receiving to be applied in different optical communication systems.