Light is a wave and waves can be absorbed. The absorption occurs at the boundary between two different elements. Once waves are absorbed, the wave’s energy gets transferred to the particles on the absorbing material.
Opaque objects tend to absorb some wavelengths when white light shines on them. Light absorbing panels work by converting light into energy. The level of absorption is subject to the electromagnetic frequency of the light and the nature of atoms in the object.
As such, frequency determines the effectiveness of light absorbing panels. When the frequency of the panels complements the frequency of light, then light gets absorbed. Otherwise, the light is reflected or passes through.
When panels absorb light, they generate heat. In some cases, the selective absorption of light takes place because the light frequency matches the frequency at which the panel’s electrons vibrate.
Usually, light absorption by panels depends on the state of their electrons. Electrons vibrate in a certain frequency commonly known as “natural” frequency. Once the light comes into contact with an atom they share the same frequency, it excites electrons in the atom resulting in vibration.
When vibrating, the electrons in the atom end up interacting with the adjacent atoms converting the vibration energy into thermal energy. As a result, the light is absorbed – not to be seen again.
Since different molecules and atoms have different natural vibration frequencies, light-absorbing panels selectively absorb visible light in various frequencies.
When a light-absorbing material consists of electrons with high natural frequency, then the material is capable of absorbing high-frequency light. Using this approach, it possible for physicists to identify the properties of a material.
Electrons in a light-absorbing material will absorb the energy of the light, which changes their state. Several things can happen after that like the electron returning to the ground state by producing a photon of light.
Alternatively, the material can retain the energy which effectively results in the absorption of light. The absorption of light by panels makes them appear dark or opaque to visible light wavelengths.
During light absorption, light beams penetrate the light-absorbing material with an equal concentration of absorbing pigments. As photons get deeper into the material, they get absorbed at various depths.
Once the photon transfers its energy to an electron in the panel, in a single event the photon disappears from the beam of light. The instant transfer of photon energy followed by the disappearance of the photon is akin to the photoelectric effect of instant ejection of an electron from photocells.
The process of “losing” photons continues with fewer photons getting to the next layer and so on. In each successive layer, a constant fraction of light is absorbed.
The constant fraction of light absorbed by each layer is independent of the light intensity. For a given light wavelength, each successive thickness of the panel will absorb the same amount of light going through it.
This results in the intensity of the light going through a light-absorbing panel to decrease with depth.
