In this paper we will discuss the implications of using all-optical OFDM in the network, the need for synchronisation and clock recovery, and demonstrate a simple all-optical clock recovery system for such superchannels. The recovered analogue clock was used to generate a second comb synchronised to the original from the transmitter.
We report for the first time an ultra-stable optical-carrier dissemination technique for transmission over a 20 km unidirectional fibre link. The optical-linewidth of the recovered carrier matches closely that of the original carrier.
In this paper we will discuss a range of applications, pertinent to phase-modulated OFDM superchannels, for which optical signal processing can be used. We demonstrate a novel technique for clock recovery of a 53.5 Gbit/s BPSK superchannel, which uses the well-known four-wave mixing process in a SOA.
We argue that the use of nonlinear semiconductor optical amplifiers for all-optical processing of phase encoded signals offers potential benefits. To illustrate the point, we demonstrate QPSK to 8PSK conversion and decomposition of QPSK to two BPSK outputs at new wavelengths by four-wave mixing.