title: Sub-GHz-resolution C-band Nyquist-filtering interleaver on a high-index-contrast photonic integrated circuit.
abstract: Modern optical communications rely on high-resolution, high-bandwidth filtering to maximize the data-carrying capacity of fiber-optic networks. Such filtering typically requires high-speed, power-hungry digital processes in the electrical domain. Passive optical filters currently provide high bandwidths with low power consumption, but at the expense of resolution. Here, we present a passive filter chip that functions as an optical Nyquist-filtering interleaver featuring sub-GHz resolution and a near-rectangular passband with 8% roll-off. This performance is highly promising for high-spectral-efficiency Nyquist wavelength division multiplexed (N-WDM) optical super-channels. The chip provides a simple two-ring-resonator-assisted Mach-Zehnder interferometer, which has a sub-cm2footprint owing to the high-index-contrast Si3N4/SiO2waveguide, while manifests low wavelength-dependency enabling C-band (> 4 THz) coverage with more than 160 effective free spectral ranges of 25 GHz. This device is anticipated to be a critical building block for spectrally-efficient, chip-scale transceivers and ROADMs for N-WDM super-channels in next-generation optical communication networks.
authors.forename: Leimeng
authors.initials: L
authors.lastname: Zhuang
authors.forename: Chen
authors.initials: C
authors.lastname: Zhu
authors.forename: Bill
authors.initials: B
authors.lastname: Corcoran
authors.forename: Maurizio
authors.initials: M
authors.lastname: Burla
authors.forename: Chris G H
authors.initials: CG
authors.lastname: Roeloffzen
authors.forename: Arne
authors.initials: A
authors.lastname: Leinse
authors.forename: Jochen
authors.initials: J
authors.lastname: Schröder
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Lowery