title: Topology optimized mode multiplexing in silicon-on-insulator photonic wire waveguides.
abstract: We design and experimentally verify a topology optimized low-loss and broadband two-mode (de-)multiplexer, which is (de-)multiplexing the fundamental and the first-order transverse-electric modes in a silicon photonic wire. The device has a footprint of 2.6 µm x 4.22 µm and exhibits a loss <1.2 dB in a 100 nm bandwidth measured around 1570 nm. The measured cross talk is <-12 dB and the extinction ratio is >14 dB in the C-band. Furthermore, we demonstrate that the design method can be expanded to include more modes, in this case including also the second order transverse-electric mode, while maintaining functionality.
authors.forename: Louise F
authors.initials: LF
authors.lastname: Frellsen
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Ding
authors.forename: Ole
authors.initials: O
authors.lastname: Sigmund
authors.forename: Lars H
authors.initials: LH
authors.lastname: Frandsen