A four green-light demultiplexer using a multi gallium nitride slot-waveguide structure

摘要

In this work, we introduce a four green-light wavelength splitter device, based on six slot-waveguide structures. Silica and gallium nitride materials were chosen for confining the green light inside the slot-waveguide area in a transverse magnetic field mode. The device functioned as a 1 x 4 demultiplexer, which demultiplexes wave-lengths in the green-light band with wavelength range of 500-530 nm with an accurate spacing of 10 nm. The coupling between the six slot-waveguide units was analyzed using the classical mode theory and the full vectorial beam propagation method. Simulation results showed that the four wavelengths could be demultiplexed after a short coupling length of 106.5 mu m with low losses around 0.108-0.127 dB, full width at half maximum around 8.99-9.39 nm, and excellent crosstalk around-21.13 to-24.1 dB. The device has the potential to increase data bitrate by utilizing the wavelength division multiplexing technique in visible light communication systems.