The photon

There are no TEM waves, only photons. Lets build a photon, using a radio antenna. A short antenna ($2L<< \lambda$) simplifies the calculation, letting $\bf B\bf $ fall off everywhere as $1/r^{2}$. The Biot-Savart law finds $B = (\mu_{0}/4\pi)(LI_{0}/r^{2})\sin \theta \sin \omega t$. The magnetic flux thru a semi-circle of radius $\lambda/2$ is set equal to the flux quantum h/e, determining the needed source strength, $LI_{0}$. From this, one can integrate the magnetic energy density over a sphere of radius $\lambda /2$ and finds it to be $1.0121 hc/\lambda$. Pretty close. A $\bf B \bf$ field collapses when the current ceases, but the photon evades this by creating a $\epsilon_{0} \partial \bf E \bf / \partial t$ displacement current at center that fully supports the toroidal $\bf B \bf$ assembly as it moves at c. This $\bf E=vxB \bf $ arises because the photon moves at c. Stopped, a photon decays. At every point along the photon's path, an observer will note a transient oscillation of an $\bf E \bf$ field. This sources the EM ``guiding wave'', carrying little or no energy and expanding at c. At the head of the photon, all these spherical guiding waves gather ``in-phase'' as a planar wavefront. This model speaks to all the many things we know about light. The photon is tiny, but its guiding wave is huge.