In the full internal reflection case where we have a refracted evanescent wave, If another object is nearby, then we could have wave tunneling phenomenon(frustrated total internal reflection). I am looking for an answer that addresses all my following concerns:
- So, how can the evanescent wave which does not transfer any net energy produce another wave at the second interface? What happens with the transfer of energy before the evanescent wave reaches the second interface and what happens to it at the exact time that it reaches it? Does energy spontaneously flow from one interface to another to produce the wave at the second interface?
- Is an evanescent light wave a standing or travelling wave?
- When the evanescent wave reaches the second interface and produces another travelling wave, then does anything happen to the reflected wave of the first interface in order to not have problem with conservation of energy or there is no such problem (and why)? And if something does happen to the reflected wave, does it happen spontaneously(when the evanescent reaches the second interface)?
- If energy is not transferred by the evanescent waves, then how does its EM wave excite the atoms(or molecules or whatever) at the second interface?
NOTE: I think the evanescent wave is a travelling wave that travels parallel to the boundary between the two media but its wavefronts are exponentially decaying. Please enlighten me.