Spontaneous emission lifetime

[Islam Ashry]

Hello,

I am using the OptiFDTD to indirectly calculate the spontaneous emission lifetime.
This can be achieved by calculating the power radiated from a point source.
I started using a simple structure like a flat substrate and I compare what I get using the FDTD method with the theory.
For dielectric interfaces, I found perfect matching between the theory and FDTD results. However, for plasmonic substrates, like gold for example, the FDTD and theoretical results are identical when the dipole at distances larger than 100 nm from the substrate. When the dipole is very near to the substrate, distance less than 100 nm, the theoretical results shows decrease to the lifetime and the FDTD results gives increase to the lifetime.
Can you help me to solve this issue?
Does the FDTD method consider the nonradiative decay when the dipole is near to plasmonic materials?
Thanks

[Ravil]

Hi Islam, did you consider the effects of spatial and polariz. coherence in your experiment?

[Islam Ashry]

Thanks Ravil. Yes, I did.

[Damian Marek]

I expect this could be a mesh resolution issue. The electric field changes rapidly near metallic interfaces and so you need a fine mesh to simulate it correctly. Have you looked into this? Either changing the global mesh settings or introducing a nonlinear mesh near the interface should improve the accuracy.

Cheers

[Ravil]

Hi Islam, did you get that fixed by non linear mesh and coher. effects?

[Islam Ashry]

Thanks guys for your help.
Unfortunately, this is NOT a mesh size issue because I went down to 4 nm mesh size without getting any improvements.
I am currently trying another solution and if it works I will let you know.
Thanks

[perveen akhter]

I want to see how the plasmonic resonance near field interact with a point source closeby. your seems somehow related. can you give me refernce of wha you are trying to do.

[Author]

Posts