Recent content by Jeffrey Yang

Well, maybe my express is not professional. What I intend to express is just because in thermal equilibrium, finally the ensemble averaged photon number ##n## should equal to the Bose-Einstein probability. What I'm thinking about is how these occupation probability is finally transferred to the...

Em..I'm not sure whether I understand your reply correctly. Here are my mind: Let's say if now we are talking about the field in the space causing light emission of a certain thermalized source (heat body, semiconductor ...). As we said, the emission operator has an eigenvalue ##n+1 =...

Hi, thanks for your answer. Well, what you are talking about make sense to me. However, it is always confusing to me that if the the 1 or 1/2 (symmetrized operator) is the spontaneous emission term, why we always ignore this term when we discuss about thermal radiation? Let's say thermal...

I know the positive field operator E+ is actually an annihilation operator a while the negative field E- is a creation operator a+. I also learned that the absorption process can be represented as E-E+, which should be the number of photons n accroding to the principle of ladder operator. Also...

Thanks for your reply. I still cannot understand the internal relationship between "losing energy" and "change of phase velocity", could you please explain more about this?

Thanks a lot

I just read some words from the book Optical Waveguide Theory by Snyder, Allan W., p226. It says that "However, although it is possible for the phase velocity of a mode to exceed the maximum speed of light in the cladding (of waveguide), c/n_cl, this cannot occur without losing power to...

The complete Maxwell wave equation for electromagnetic field using the double curl operator "∇×∇×". Only when the transverse condition is hold, this operator can equal to the Laplace operator and form the helmholtz. My question is what's the condition can we use the helmoltz equation instead of...

Thanks to your reply Em...Exactly same to what I'm thinking about. Although the function is discontinuous at the boundary, that doesn't mean this differential result is not well behaved. Then we should be able to extend the function safely and then use the Green's identity.

As required by the Green's identity, the integrated function has to be smooth and continuous in the integration region Ω. How about if the function is just discontinuous at the boundary? For example, I intend to make a volume integration of a product of electric fields, the field function is...

Thanks for your book!

Thanks DrDu! This is what I'm thinking about. This consideration is safe and correct in the far field region. However, I still want to confirm that this is also true in the near field region. If we consider the absorption, or dissipation, of electromagnetic energy in the near field, I think we...

When the dipole emit EM field, it contains both the transverse and longitudinal component. It is true that at the far-field region, there is only transverse left and we can safely say that only the transverse component transfer energy. But how about at the near-field region? Actually, in the...

I read this statement in this paper http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.68.3698. I just start at this area and have no enough basic knowledge. Could you please explain to me what's the meaning of the "transverse mode" here? For a dipole, does the transverse mode here...

Hello everyone: This is what I read in a paper, the spontaneous emission rate written by Fermi's Golden Rule is just related to the local transverse electric field. Dose anyone can explain to me what's the meaning of "transverse mode" here? Why the emission is not related to longitudinal...