Photon Polarization / Superposition of States

We can ask ourselves what the subject ‘looks like’, at the single-particle level, of polarized light. We know that at the level of wave-mechanics, both plane-polarized and circularly-polarized light are easy to understand: Either way, the dipole-moments are at right angles to the direction of propagation, all the time, even if randomly so. But there also needs to be a particle / photon -based explanation for all the properties of light, in order to satisfy the demands of Quantum Mechanics.

And so a key question could be phrased as, ‘If we pass randomly-polarized light through a simple linear polarizer, which consists of a gel-block, and which absorbs EM vibrations along one disfavored axis, maybe because it has been made ohmic along that axis, why is the maximum intensity of plane-polarized light that comes out, in fact so close to 50% of the intensity, of the randomly-polarized beam that went in?’ Using wave-mechanics, the answer is easy to see, but using particle-physics, the answer is not so obvious.

And one reason fw the answer may not be obvious, is because we might be visualizing each photon, as being plane-polarized at an angle unique to itself. In that case, if the polarizer only transmits light, which is polarized to an extremely pure degree, the number of photons whose plane of polarization lines up with the favored angle perfectly, should be few-to-none. Each photon could then have an angle of polarization, which is not exactly lined up with the axis which the polarizer favors, and would thus be filtered out. And yet, the strength of the electric dipole-moment which comes out of the polarizer, along the disfavored axis, could be close to zero, while the total amount of light that comes out, could be close to 50% of how much light came in.

If each incident photon had been plane-polarized in one random direction, then surely fewer than 50% of them, would have been polarized, in one exact direction.

(Updated 04/10/2018 … )

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About Bosons and RF Antennas

Particles in Physics are essentially of two types:

  • Bosons
  • Fermions

Fermions are thought to be particles, that best approximate the intuitive understanding of ‘matter’.

Bosons are harder to understand, because they’re thought to be particles that actually translate a force.

Hence, an Electron is both a Fermion and a Lepton, while a Photon is clearly a Boson.

One of the facts which we know about Electromagnetic Radiation, is that at its longest wavelengths, and thus at its lowest frequencies, it resembles waves the most, while at its shortest wavelengths it strongly resembles particles, and its frequencies are even disregarded.

And so an idle question which some people might ponder, is when given the longest-wavelength form of EM Radiation: Radio-Frequency Waves, how could wave / particle duality still hold? The short answer which I’d have to that question would be, ‘In the photons having a ridiculously high number.’ The energy of one photon is inversely proportional to its wavelength. The wavelengths of visible light range from 400 to 700 nanometers. At the same time, its photon energy is close to 1.2 eV.

I leave it to the reader to compute, if he is operating a shortwave transmitter with a wavelength of 10 meters, what the corresponding photon energy would be ! In any case, practical RF transmitters radiate anywhere from 5 to 5000 Watts. If the effective number of resulting photons is to be computed, then the fact must also be accounted for, that an Ampere-Second is a Coulomb of charge. This will tell us, how many Joules of energy, 1 eV is.

1 J = 1 C ⋅ V = 1 W ⋅ S .

Further, if Electromagnetic Phenomena become very low-frequency, or even D.C. Phenomena, then their photons are thought to take the form of virtual particles.

Dirk