We study the effects of pulse distortion on four-wave mixing (FWM) for different slow-light architectures. REMZI has the highest FWM conversion. Distortion constraint limits the performance of FWM conversion in CROW with higher number of stages.
Researchers studying slow light via stimulated Brillouin scattering have demonstrated that it is possible to minimize pulse distortion by tailoring the higher-order dispersion of the material, operate at data rates over 10 Gb/s using broad-band pump light, obtain controllable delays exceeding one pulse width, and delaying pulses with minimal change in the pulse amplitude. Spurred by this work, there is active research in obtaining slow light in optical wave guides by stimulated Raman scattering and by the four-wave mixing process. Also, researchers are moving into the nonlinear regime to study slow-light with optical solitons. Simultaneously, results from the basic science laboratories are transitioning to applications-oriented laboratories who are integrating slow-light sub-assemblies into functions telecommunication components.
Under the constraint of fixed pulse distortion, we study the bandwidth-delay product and nonlinear phase shift performance of coupled-resonator slow-light waveguides with designs that produce maximally-flat transmission and maximally-flat group delay responses. Even though improvement in bandwidth-delay product can be obtained with increasing number of resonators, the nonlinear response fails to improve beyond a certain number of resonators due to the increased filter bandwidth necessary to maintain a fixed pulse distortion. However, as expected, the nonlinear response improves with resonator finesse and degrades with resonator loss.