Multistage dispersion compensator using ring resonators

A compact, multichannel dispersion-compensating filter is demonstrated with $D=-4200 \mathrm{ps}/\mathrm{nm}$, a $\pm 5‐\mathrm{ps}$ group delay ripple, $<3‐\mathrm{dB}$ loss, and a 4.5-GHz passband width out of a 12.5-GHz free spectral range. We show that multistage designs can achieve a substantial increase in passband width and peak dispersion for a given group-delay ripple compared with single-stage designs. The dispersion-compensation effectiveness was demonstrated in a 320-km, seven-channel nonlinear system simulation for OC48 signals.