Coherent Electro-Optical Transceivers for High-Speed Data Links

Coherent optical transceivers — first introduced to the market in 2008 — have proved to be a key technology for increasing data-rates of optical serial links. Most long-haul and metro optical networks now use coherent interfaces. After reviewing the operating principle of coherent optical systems, this talk will present recent advances and future directions of coherent electro-optical transceivers, including Photonic Integrated Circuits (PIC), Digital Signal Processing (DSP) and integrated Analog Front-Ends (AFE). The talk will focus on integrated TransImpedance Amplifiers (TIA) and linear modulator drivers in SiGe BiCMOS technology, and conclude with a brief overview of the research in the Nokia Advanced Optics group that enables us to deliver these products. We will discuss some of the challenges in the next generation (260GBd) that will go unto 150GHz subject to the usual non-confidentiality restrictions.