This paper presents a top-down approach to the design of all-silicon CMOS-based fully integrated optical receivers. From the system-level requirements, we determine the optimum block-level specifications, based on which the individual building blocks are designed. Measurement results of the manufactured design show operation at data rates exceeding 2.5-Gbps/channel for the detector, the amplification and the clock and data recovery circuits. This proof of concept is the first step towards design optimized, completely integrated, multi-channel optical receivers for high-bandwidth short-distance chip-to-chip interconnects.