This book presents several circuits that are required for the full integration of an optical transmitter in standard CMOS. The main emphasis is placed on high-speed receivers with a bitrate of up to 1 Gb/s. The possibility of including the photodiode in a receiver is investigated and the problems encountered are discussed. Concerning the transmitter aspect, a CMOS LED driver is described. The final chapter addresses electrical interference problems on a chip and proposes countermeasures. The various circuits in this book have all been realized and measurement results are presented, paving the way for single chip communication systems in which the optical interfaces are integrated on the same die as the digital circuitry.