Based on a large number of experiments, this paper summarized the parameter demands for each module of closed loop control circuit and designed a corresponding hardware circuit using FPGA. The proposed twice closed loop technique improved the zero offset stability of. The main aim of this paper is to present an approach to establish optical fiber communication by employing the standard IEEE 802. 3 Ethernet and Optical Sensing circuits that can be implemented on an FPGA. The design uses Micrel's MIC3003 controller, the 10G DFB/FP laser driver SY88022AL, and any of the following 10G limiting amplifiers: SY88053C/073L. A picture of the fully loaded board is shown on the next page. We built (in a small team) a 10Mbps fibre optic link for a CUED 3rd year project., Department of Earth and Space Science and Engineering, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada 3Dr, Department of Earth and Space Science and Engineering, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada E-mail: 1qdsun@ee. ca. The SFP ports on imperix controllers are typically used for interconnecting devices in a RealSync network. Aurora 8B/10B or Aurora 64B/66B can be. Abstract: Fiber optic communication is the main communication mode of data communication system nowadays, and its performance directly affects the quality of data communication system.