1?×?4 MMI visible light wavelength demultiplexer based on a GaN slot-waveguide structure

摘要

High transmission losses are the key problem that limits the performance of visible light communication systems, which work on wavelength division multiplexing (WDM) technology.To overcome this problem, we propose a novel design for a 1?×?4 optical demultiplexer based on the multimode interference in a slot-waveguide structure that operates at 547?nm, 559?nm, 566?nm, and 584?nm. Gallium nitride and silicon oxide were found to be excellent materials for the slot-waveguide structure. Simulation results showed that the proposed device can transmit four channels that work in the visible light range with a low transmission loss of 0.983–1.423?dB, crosstalk of 13.8–18.3?dB, and bandwidth of 1.8–3.2?nm. Thus, this device can be very useful in visible light networking systems, which work on the WDM technology.