Ultra-High-Speed Optical Time Division Multiplexing

The serial optical data format has attracted attention for decades now, because of its promise to reduce the number of active components in a communication system. Indeed, historically increasing the serial bit rate by a factor of 4, reduced the cost per bit by 40%. Going beyond the available electronic bandwidth (roughly 100 GHz today) can be obtained using optical time division multiplexing (OTDM), and symbol rates up to 1.28 Tbaud per polarization have been demonstrated. As most optical signal processing devices operate on a per channel basis, it is advantageous to aggregate the data in a serial format, since this allows for optical signal processing of many bits in a single device. This chapter gives an overview of the state-of-the-art of OTDM systems to reach multi-Tbit/s serial data and means to handle these ultra-high bit rate signals using for instance nonlinear silicon waveguides for e.g. serial-to-parallel conversion.