Understanding Photon Phase

Single helium/neon laser photons

(630 nanometers, 1.97 evolts)

  • Single 630 nanometer photon acting as a wave.
    Turn the lights down low to see an animation of a single 630 nanometer photon trapped in a 2520 nanometer cavity, 2.5 micrometers wide or 4 wavelenghts wide. The grid is marked at 1/2 wavelength intervals. The single photon expands and contracts at a predictable rate that matches its wavelength.
  • Two 630 nanometer photons
    Trapped in a 2520 nanometer cavity, 2.5 micrometers wide or 4 wavelengths wide. The second photon is released 0.1 femtoseconds after the first and travels at the same speed of light, just behind the first. Both photons expand and contract, the location of maximum and minimum size is called the "phase" of the wave. These two photons are "in-phase", ie. coherent.
  • Three "Helium/Neon" laser photons
    Three photons generated at the same spot with a 0.1 femtosecond delay. This results in the first photon being 0.1 femtoseconds ahead of the second photon and the third photon being at the end. They have a high probablity of being reflected at the end points since they are in the "maximum size" state. Photons have a high degree of interacting with an electron when they are tiny. Photons also have a high chance of causing a "stimulated emission" of another photon when they are tiny. This effect causes the new photons generated to be "in-phase" with the existing photons.
  • Ten 630 nanometer photons released over 1.0 femtoseconds
    The release of 10 photons fills a 1/2 wavelength piece of space. The first photon will have expanded and contracted and is 1/2 a wavelength away from where it started when the 10th photon is released. Each photon as it travels, periodically goes from its "normal-particle" state to its "anti-particle" state over one wavelength, represented here as the transition from black to white.
  • Burst of photons
    Animation of a 4.0 femtosecond burst of 630 nanometer photons (photons from a common helium/neon laser) trapped in a cavity that is 4 wavelengths wide. You can see re-enforcement of the wave when the back part of the wave catches the front edge on reflection from the sides of the cavity. These photons would be called coherent.

Energy

The only thing for sure about energy, is that its a long way away in a very short time. Ie. in one second its 186,000 miles away.

Photons - Energy and Wavelength

Although all photons travel at the speed of light, a photon's energy is related to its wavelength. High energy photons expand and contract very quickly, low energy photons expand and contract more slowly.

Low energy photons will grow to large sizes (wavelength) compared to a higher energy photon that will only grow much smaller in size.

The Planck constant

The Planck constant is equal to 6.626*10^-34 Joule-Sec. and establishes the relationship between wavelength and energy. A short length = high energy (ultraviolet) and a long length = low energy (heat).

To convert from length to energy, take 1240 divided by the nanometer wavelength to get the energy in evolts. For a 630nm helium/neon laser photon 1240/630nm=1.97ev