Learning Forum

[YUZI SONG]

Hi Greg Baethge,

 

I am Yuzi Song, a PhD student at Research school of Physics in Australia National University.

 

I am writing to ask you about the way to calculate dipole power and source power that we use to calculate the Purcell factor of the multiple dipoles.

 

Firstly, we know the fomula to calculate the Purcell factor from the following page

Purcell factor of a microdisk – Ansys Optics

purcell_factor=dipolepower(f)/sourcepower(f);

 

That means that if we want to calculate the purcell factor, we need to calculate the dipole power and source power firstly.

 

(1) The source power script function returns the power the dipole source would radiate in a homogeneous medium.   sourcepower - Script command – Ansys Optics

 

(2) The dipolepower script command returns the power that was injected into the simulation region, and is equivalent to measuring the power transmitted out of a small box surrounding the dipole. dipolepower - Script command – Ansys Optics

 

For 1 dipole, it is obvious that we can obtain the dipole power by using the transmission box or dipolepower script command, and then obtain the source power by using the sourcepower script command and the get the purcell factor.

 

But for more than 1 dipole, as you said above, because "Interference between the two sources mean the total radiated power is not simply the sum of what each dipole would radiate by itself"  and  "The Power box and Dipolepower methods correctly take this interference into account " , so "The Sourcepower method is not correct because it simply reports the sum of what each source would radiated by itself. Therefore, when calculating the total power radiated by sources in simulations with multiple sources, you should use the Power box or Dipolepower methods."

 

(1) My first question is whether " the total power radiated by sources " above is the  " Sourcepower(f) in Purcell factor " or "Dipolepower(f) in Purcell factor "?

 

(2)If " the total power radiated by sources " above is the  " Sourcepower(f) in Purcell factor " , dose it means that in multiple dipoles situation, the Sourcepower(f) in Purcell factor should be replied by " Power box or Dipolepower"? But if we reply it, how about dipolepower(f) in purcell factor?

Or if " the total power radiated by sources " above is the  " dipolepower(f) in Purcell factor " , dose it  means that in multiple dipoles situation, the dipolepower(f) in Purcell factor is still the data from " Power box or Dipolepower"? But in this situation, how to calculate  the sourcepower(f) in purcell factor (If we simply use the sourcepower command in multiple dipole situation, the interference between those dipoles may be not considered)?