LCML - Grating coupler based on FDTD simulation results | lcml_gc_te_1550_fdtd



This grating coupler model is built by using simulation results from FDTD Solutions. Please refer to the Grating Coupler 2D FDTD and Grating Coupler 3D FDTD pages for the detailed information on the component-level simulation of the grating coupler.

This compact model also takes advantage of the Ports object in FDTD Solutions 8.17+ and the S-Parameter matrix sweep feature to facilitate the parameter extraction process.

Example Test File

grating_coupler_te.icp (196.8 KB)

User Guide

lcml_gc_te_1550_fdtd (gc)

LCML: grating coupler for TE mode based on FDTD simulation.


Name Type
opt_1 Optical Signal
opt_2 Optical Signal

Model Development

FDTD Solutions
1.Open the file grating_coupler_2D.fsp. This file can be found in the LCML_resource folder in the download page. The grating coupler structure in this file is shown below (XY view). For the implementation details of this 2D FDTD grating coupler, please refer to the Grating Coupler 2D FDTD page.

2.Run the sweep object “s-parameter sweep” defined in the FDTD file. This sweep will alternate the input port hence get the full s-matrix [S11, S12; S21, S22] of the grating coupler. After the sweep is completed, right click on the sweep object and choose ‘Export to INTERCONNECT’. A file browser window will then pop out and user could save the file. In this example, the s-parameter file is saved into gc_S_FDTD.dat.


1.In INTERCONNECT, create a compound element.

2.Add two bidirectional optical ports: “opt_1” (left) and “opt_2” (right), and arrange their positions.

3.Expand the compound element, drag and drop an Optical S-Parameter element to the schematic editor and connect the relays and ports according to the following figure.

4.Edit the Optical S-Parameter element properties, load the s-parameter file gc_S_FDTD.dat into the element.

5.Back to the compound element and set icon. Set the “model” of the compound element to be “lcml_gc_te_1550_fdtd” and the “prefix” of it to be “gc”.


Download the simulation file grating_coupler_te.icp from the top of this page. In this simulation file, the grating coupler is connected to and measured by an Optical Network Analyzer (ONA). Click on the “run” button and the ONA will be populated with the simulation results. To view the simulation results, user can right click on the results and select “Visualize”.

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