How Light Interacts with a Tattoo
Submitted 04.07.23
How Light Interacts with a Tattoo
“...if you think about a glass of water when you shoot a flashlight through the glass you can see the light bend the index of refraction inside of the glass.”
-Shawn Bellina, S8 Chemist
A Photons Journey
When light hits the surface of the skin, it is partially reflected and partially transmitted. The transmitted light then passes through the epidermis (the outer layer of skin) and dermis (the inner layer of skin). The epidermis is composed of cells that are translucent, meaning they allow light to pass through them.
Light as it travels deeper into the skin has an amount of force. As that force moves through the skin cells it refracts and loses energy until it reaches the tattoo pigments. The tattoo pigments cause some of those photons to absorb and some to reflect. Then the reflected photon travels back through the skin losing more energy being absorbed in the skin cells until it reaches your eye. That energy loss is measured in wavelengths, and wavelengths also translate to colors. We will touch on several of these terms further down the article.
