Visible wavelength light at the nanoscale

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Optical wavelength light at the nanoscale?
It is homogeneous and monochrome (for passive interactions at least).
Saying that optical light at the nanoscale does not even make physical sense (as sometimes done) is incorrect.

No resolvable structure below the Abbe limit for passive observations

Color at the nanoscale?!

It's not that there is no color and light at the nanoscale.
It's just that when you go to size scales below the wavelength of light
(below the Abbe limit to be more precise) you can't separate individual spots anymore
Everything blurs till you don't see anything except one monochome color and brightness.
This is because the effects of refraction are averaged out to a smear.
It's also visualizeable with Huygens elemental waves.
Making something like a mathematical fold removing details.

Lights being homogeneous and monochrome at the nanoscale
at least for all passive interactions with in-falling light.
There is more though ...

Super-resolution from light emission from nanoscale point like sources

Sources of active emission of light from formerly somehow excited electronic states though
can be much smaller than the wavelength of light.
So this allows for optical color variations on size scales much shorter than the wavelength of light.
This cheat is used e.g.

  • in super-resolution microscopy and
  • in super-resolution photo-curing resin 3D printing.

Optical super-resolution on actively light emitting samples can be achieved:

  • in the near field: "Near-field scanning optical microscopy (NSOM) "
  • and even in the far field by some fancy tricks

Point emission sources can be:

  • fluorophores - phosphorescent centers
  • poly-aromatic pigment molecules
  • color centers in gemstones / mineral pigments (?)

A spherical wave is emitted when an excited electronic state relaxes.

Related

External links

And how to cheat it at least a bit: