On the side of the excitation, an additional slit of same width and depth is etched on the 220nm silicon layer to minimise the reflection of the input beam. A grating is created by etching equally-spaced slits in the epitaxial silicon layer, with an etch width of 160nm and an etch depth of 220nm. An additional epitaxial silicon layer of thickness 150nm is grown locally on top in order to increase the directionality of the grating. Modelling of the structure in FIMMPROP Description of the structureĪ 220nm-thick Si layer is grown on top of a 2um-thick SiO2 layer. This structure can also be modelled in 2D with our EingenMode Expansion tool FIMMPROP you The FDTD EngineĪllows you to run initial calculations quickly and with reasonableĪccuracy, and you can then use the FETD Engine once you want to obtain Useful to check the accuracy of your calculations. The structure is modelled here in 2D but it can also be modelled in 3Dįinite-Difference Time-Domain and Finite-Element Time-Domain methods,Īnd run the same simulation using two independent tools. Insulator, SOI) with a grating optimised for vertical fibre coupling, taken from a popular publication from Ghent University. Popular fiber-to-chip coupler for a silicon waveguide (silicon on OmniSim's FDTD and FETD engines were used to model a vertical grating structure used to couple light from a planar Surface Grating Coupler Design Utility to automatically design and simulate surface grating
#FDTD SIMULATION SOFTWARE SOFTWARE#
A vertical fibre to waveguide grating coupler Simulated with OmniSim software