Learning Forum

[Pengsheng Zhang]

Hi,

Greetings. Since the transmission is defined as the formula shown by the following figure,

 

How does FDTD define the 'sourcepower' when 2 single-wavelength sources are set? By the way, can I use this formula to calculate transmission in this case?

Thanks a lot.

[Afroditi Petropoulou]

Dear Pengsheng,

 

Thank you for contacting us.

 

As explained in sourcepower - Script command – Ansys Optics, if multiple sources are used, the sourcepower(f) command will return the sum of all sourcepowers from all sources. If you want to calculate the sourcepower from a specific source, you need to use sourcepower(f, option, name), where “name” is the name of this source.

 

If you have two sources each corresponding to a different single wavelength, most of the power for this wavelength will come from the corresponding source. For example, let’s assume that you have two sources named source_400 which has wavelength of 400nm and source_700 which has wavelength of 700nm. If you look at the sourcepower that corresponds to 400nm using script, you will get the following results:

 

 

The sourcepwer of source_700 that corresponds to 400nm wavelength is 11 orders of magnitude lower than the one of source_400. Hence, if you use sourcepower(f_400) without specifying the source name, you will get the sourcepower of source_400 since the sourcepower of source_700 at 400nm wavelength is negligible.

 

Best regards,

Afroditi