Lumped time-delay compensation scheme for coding synchronization in the nonlinear spectral quantization-based all-optical analog-to-digital conversion

In this paper, we propose a novel lumped time-delay compensation scheme for the all-optical analog-to-digital conversion based on soliton self-frequency shift and optical interconnection techniques. By inserting a segment of negative dispersion fiber between the quantization and the coding module, the time delay of different quantized pulses can be accurately compensated with a simple structure compared to the multiple time-delay lines. The simulation results show that the coding pulses can be well synchronized using a span of fiber, with the flattened negative dispersion within the wavelength range of 1558–1620 nm. In addition, the problems of pulse broadening and time error are discussed, and it is shown that no damage happens to the coding correctness within the sampling rate of 30 GSa/s.