Full 16 channel OTDM-WDM conversion using a temporal optical Fourier processor

We experimentally demonstrate and analyze through simulation an OTDM→WDM serial to parallel converter that fully extracts all 1610-Gb/s WDM channels from a 160-Gb/s OTDM data stream in a single device using an optical Fourier processor. The device operates by dispersing a pump pulse across all OTDM channels and using the nonlinear optical process of four-wave mixing (FWM) to parallelize all channels simultaneously. The requisite temporal overlap of adjacent pump pulses gives rise to crosstalk from a non-degenerate FWM process. Decreasing the temporal overlap of the pump pulses, reduces this source of crosstalk but also decreases the channel power and spectral isolation at the edge of the generated WDM spectrum leading to increased crosstalk from adjacent channels in this region. We find that a balance between adjacent channel crosstalk and non-degenerate FWM crosstalk through optimization of the pump overlap is critical to ideal operation of the device.