TFSF Source in Ansys Lumerical FDTD — Lesson 3

Physics & Applications

TFSF source is a variation of the planewave source. In this video lesson, you will learn how to use it to study the scattering properties of particles.

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Setup & Tips

In this video lesson, we will demonstrate how to set up the TFSF source using a simple particle-on-substrate example. You can download the simulation file and follow the steps shown below:

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Add a TFSF source:

1. Click the arrow next to the “Sources” button in the main toolbar to open the drop-down menu

2. Click the “Total-field scattered-fields” option which is the fourth in the list in the drop-down menu

Open the source edit window:

1. Make sure that the source is selected in the Objects Tree window. If not, click the source in the Objects Tree to select it

2. Click the Edit button in the edit toolbar on the left (pencil icon), or use the 'E' keyboard shortcut to open the edit window

Set properties in the source edit window:

1. General tab:

• Injection axis: z-axis
• Direction: Backward
• Angle theta: 30 degrees
• Angle phi: 0 degrees
• Polarization angle: 0 degrees

2. Geometry tab:

• x: 0 microns
• x span: 0.3 microns
• y: 0 microns
• y span: 0.3 microns
• z: 0.1 microns
• z span: 0.3 microns

3. Frequency/Wavelength tab:

• Wavelength start: 0.63 microns
• Wavelength stop: 0.63 microns

4. Click the “OK” button at the bottom right of the source edit window to accept the settings

Check CAD view and run the simulation:

1. Check that the grey shaded region around the source does not intersect with the scattering particle or monitor

2. Click the “Run” menu from the simulation toolbar

Plot the far-field angular profile of scattered fields:

1. After the simulation has been completed, right-click the “monitor” object and select Visualize ->E from the context menu

2. Right-click the “R” monitor in the Objects Tree window and select Visualize->farfield from the context menu

3. Click “OK” in the frequency selection window to continue with the far-field projection calculation