Techniques to realize flexible optical terabit-per-second transmission systems

In this paper, we review emerging technologies to build up Tb/s per channel transmission capacity. We discuss the appropriate choice of modulation formats as well as options for generation and multiplexing of multiple lower bit rate subchannels. Different multiplexing approaches, mainly based on various implementations of orthogonal frequency division multiplexing and Nyquist wavelength division multiplexing are introduced. Their main strengths and weaknesses are discussed by means of selected experimental demonstrations.