Photonic density of state in matter

[Jeffrey Yang]

I'm a beginner in quantum optics. I always become confusing when the material's refractive index is complex. This time is about the photonic density of states.

We know that if the material is not absorbing or dissipative, meaning the refractive index is a real number, the local photonic density of states is proportional to the cubic of the refractive index. It seems that even when the refractive index is complex, its imaginary part will not affect the result because the imaginary part will not affect the amplitude and have nothing to do will the wave-vector as well as the dispersion relation.

On the other hand, the local photonic density of state can be characterized by the emitted power from the source according to Fermi's Golden Rule. A very strange thing is in a dissipative media, the actual emitted power will be larger than the non-dissipative one even the real part of refractive index is the same, meaning the local photonic density of state will also be affected by the imaginary part of the refractive index . I observe this result in optical simulation and can accept it according to my daily-life intuition. But I cannot find the theoretical explanation. Does anyone can help me to understand it?

 

[Greg Bernhardt]

Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

 

[Jeffrey Yang]

No, it's fine