Reply To: Can we use a dipole source with a single frequency?

[Kirill]

Dear Subscriber,

In FDTD, since it’s a time-domain method, pulse signals are always used, which means they have a finite width in the frequency domain. This happens even if you set the start and stop wavelengths to the same value.

Usually, this isn’t a problem because the monitors automatically use the source wavelength limits, which filter out the wavelength you’re interested in.

If you really need to narrow the source bandwidth, you can switch to "Set Time Domain" and increase the pulse length a lot. Just keep in mind that this approach usually isn’t ideal because you’ll also need to extend the simulation time to get good results.

Also, check out the page: Changing the source bandwidth in FDTD and MODE – Ansys Optics.

Best regards,
Kirill