In this tutorial overview, we survey some of the challenging problems facing Optical Transport and their solutions using new semiconductor-based technologies. Advances in 0.13um CMOS, SiGe/HBT and InP/HBT IC process technologies and mixed-signal design strategies are the fundamental breakthroughs that have made these solutions possible. In combination with innovative packaging and transponder/transceiver architectures IC approaches have clearly demonstrated enhanced optical link budgets with simultaneously lower (perhaps the lowest to date) cost and manufacturability tradeoffs. This paper will describe:
*Electronic Dispersion Compensation broadly viewed as the overcoming of dispersion based limits to OC-192 links and extending link budgets,
*Error Control/Coding also known as Forward Error Correction (FEC),
*Adaptive Receivers for signal quality monitoring for real-time estimation of Q/OSNR, eye-pattern, signal BER and related temporal statistics (such as jitter).
We will discuss the theoretical underpinnings of these receiver and transmitter architectures, provide examples of system performance and conclude with general market trends. These Physical layer IC solutions represent a fundamental new toolbox of options for equipment designers in addressing systems level problems. With unmatched cost and yield/performance tradeoffs, it is expected that IC approaches will provide significant flexibility in turn, for carriers and service providers who must ultimately manage the network and assure acceptable quality of service under stringent cost constraints.