Systematic design study of an all-optical delay line based on Brillouin scattering enhanced cascade coupled ring resonators

We present a technique to improve the slow-light performance of a side-coupled integrated spaced sequence of resonators (SCISSOR) combined with a stimulated Brillouin scattering (SBS) gain medium in optical fibers. We evaluate device performance of SCISSOR-only and SCISSOR + SBS systems for different numbers of cascaded resonators from 1 to 70 using two different data fidelity metrics including eye-opening and mutual information. A practical system design is demonstrated by analyzing its performance in terms of fractional delay, power transmission, and data fidelity. We observe that the results from the two metrics are in good agreement. Based on system optimization under practical resource and fidelity constraints, the SCISSOR consisting of 70 cascaded resonators provides a fractional delay of ~ 8 with 22 dB attenuation at a signal bit rate of 10 Gbps. The combined optimal SCISSOR (with 70 resonators) + SBS system provides a improved fractional delay up to ~ 17 with unit power transmission under the same constraints.