title: Silicon dual-ring modulator driven by differential signal.
abstract: A silicon dual-ring modulator consisting of two serially cascaded rings with embedded PN junctions is driven by a differential signal pair. We show by simulation and experiment that the device has advantages over the single-ring modulator in terms of optical bandwidth, 3-dB modulation bandwidth and bit rate, at the expense of a 1.7-dB increase in the transmission penalty and a twofold increase of the RF power consumption. Driven by differential pseudo random binary sequence (PRBS) signals of 0.5-V peak-to-peak voltage (Vpp), the dual-ring modulator exhibits optical bandwidths of 66 pm and 40 pm at 12.5  Gb/s and 20  Gb/s, respectively. In contrast, the single-ring modulator has an optical bandwidth of 26 pm under a single-end PRBS signal of 0.5  Vpp at 12.5  Gb/s, and its eye diagram closes if the bit rate rises to 20  Gb/s.
authors.forename: Hui
authors.initials: H
authors.lastname: Yu
authors.forename: Marianna
authors.initials: M
authors.lastname: Pantouvaki
authors.forename: Peter
authors.initials: P
authors.lastname: Verheyen
authors.forename: Guy
authors.initials: G
authors.lastname: Lepage
authors.forename: Philippe
authors.initials: P
authors.lastname: Absil
authors.forename: Wim
authors.initials: W
authors.lastname: Bogaerts
authors.forename: Joris
authors.initials: J
authors.lastname: Van Campenhout