Dipole Source in Ansys Lumerical FDTD — Lesson 6

Physics & Applications

A dipole source is a point source with an omnidirectional radiation pattern. In this video lesson, you will learn about various settings and options in the dipole source.

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Setup & Tips

In this video lesson, we will demonstrate how to set up the dipole source using a whispering gallery mode example. You can download the simulation file and follow the steps shown below.

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Add a dipole source:

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

2. Click the “Dipole” option which is the first in the list in the drop-down menu.

3. Make sure the cursor mouse mode is selected in the mouse mode toolbar on the left.

4. Using the mouse cursor, click the dipole source in the XY view and drag the source to a position near the edge of the cylinder object.

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:

• Dipole type: Magnetic dipole
• Theta: 0 degrees
• Phi: 0 degrees

2. Frequency/Wavelength tab:

• Wavelength start: 0.418 microns
• Wavelength stop: 0.418 microns

3. Click the “OK” button at the bottom right of the source edit window to accept the settings and check the dipole orientation in the CAD view
windows.

Add additional dipoles by duplication:

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 duplicate button in the edit toolbar on the left to duplicate the dipole.

3. Click the duplicate button again for each additional dipole you want to add.

4. Make sure the cursor mouse mode is selected in the mouse mode toolbar on the left.

5. Using the mouse cursor, click the new dipole sources in the XY view and drag them to different locations within the cavity.

Run the simulation and plot the resonant mode profile:

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

2. After the simulation has been completed, right-click on the profile monitor named “monitor” and select Visualize ->H from the context menu.