This thesis describes the design and implementation of an optical fiber based high speed interface between two computers. The system is particular in that the data transits in a Field Programmable Gate Array (FPGA) situated between each computer and the optical fiber link. The measured full duplex speed for exchanging data between two C programs running on two different computers is over 8Gbit/s, including encoding, protocol and software overhead. This design is suited for applications requiring high bandwidth between two computers, and since an FPGA sees all the data being exchanged, it can be used as a fast and flexible data processing tool: Error correction, debug support, data analysis, encryption and compression are all possible uses where the FPGA can save the Central Processing Unit (CPU) an important amount of computing cycles.