Silicon-on-insulator mode-selective add-drop unit for on-chip mode-division multiplexing

Abstract

A broadband, low-crosstalk, mode-selective add-drop multiplexer using quasi phase-matching and staged coupling is presented. This ultra-compact device can be used to enable mode-division multiplexing for further increasing the aggregate bandwidth of on-chip optical interconnects.

WDM-compatible mode-division multiplexing on a silicon chip

“…Previous implementations of on-chip mode multiplexers based on Mach-Zehnder interferometers 20,21 , Multimode Interference couplers [22][23][24] , asymmetric directional couplers [25][26][27] and y-junctions [28][29][30] typically had large footprints, complex and strict design limitations or only supported a limited number of optical modes. A compact and reconfigurable mode (de)multiplexer that can be straight-forwardly scaled to support numerous modes is essential for realizing MDM-WDM in integrated photonics.…”

Silicon Multimode Photonic Integrated Devices for on-Chip Mode-Division-Multiplexed Optical Interconnects

“…Recently, a two-channel mode multiplexer was demonstrated experimentally by using an asymmetric Y-junction based on SOI nanowires [85]. The Y-junction can be also cascaded in series to handle more mode channels [86]. These devices based on adiabatic mode-evolution couplers usually suffer from the large footprints [87].…”

“…In [76], a design based on multi-mode interference is proposed, but works for two mode-channels only and is not easily extendable for more modechannels. Adiabatic mode-evolution couplers have also been proposed to realize mode (de)multiplexing by using directional couplers [77][78][79] or Y-junctions [80][81][82][83][84][85][86], which can be extended to handling with more mode-channels. In Refs.…”

“…For example, recently a ∼ 300 µm-long two-channel mode (de)multiplexer based on adiabatic couplers was demonstrated by using 340 nm-thick SOI nanowires to combine/separate two supermodes in a bus waveguide with two cores [79]. Y-junctions provide another attractive option to realize mode-conversion/(de)multiplexing [80][81][82][83][84][85][86]. In Ref.…”

Mode-selective wavelength conversion based on four-wave mixing in a multimode silicon waveguide

“…This technology is also promising in order to increase the capacity of silicon databusses for on-chip optical interconnections [2][3][4][5][6][7] . MDM may be used to enhance the throughput of the interconnections while limiting the number of required optical sources 2 , whose integration onto the silicon platform is still the object of investigations.…”