Limitations of self-phase-modulation-based tunable delay system for all-optical buffer design

The distortion, noise, and bit-delay performance of a self-phase- modulation-based tunable delay system are analyzed. The pulse amplification required for achieving large spectral broadening results in large amplifier noise. We quantify the resulting delay versus signal-to-noise ratio trade-off. We demonstrate that for high bit rates it is difficult to achieve both large bit delay and good data fidelity. We find that for a given bit rate, reducing the duty cycle improves the fractional bit delay. For a duty cycle of 16%, a maximum bit delay of 15 bits is achieved.