Ultra-fast optics for broadband photonic communication systems

The ever-increasing demand for bandwidth in telecommunication networks is accelerating the use of optical fibre for broadband communication systems. In order to continue to increase the data rate of single channel optical communication systems, it is anticipated that Optical Time Division Multiplexing (OTDM) techniques will be used in future photonic systems. OTDM technologies should allow the transmission of information at data rates in excess of 100 Gb/s on a single wavelength, and by employing OTDM in conjunction with Wavelength Division Multiplexing (WDM), it should be possible to develop highly flexible, and spectrally efficient, multi-terabit/s optical networks. An essential element of any OTDM system will be the generation of sub-picosecond pulses to represent the data. The temporal and spectral purity of the optical pulses at the transmitter will essentially determine the overall data rate that can be achieved. In order to provide the multi-terabit/s data rates required, these pulses must be compressed into the pico- and sub-picosecond range. This paper will look in greater detail at this key element involved in an all-optical time division multiplexed system, namely the generation of sub-picosecond optical pulses, and it will explore the type of system performance that can be achieved given the spectral and temporal purity of the optical pulses.