Page 130 - An Introduction to Laser Tattoo Removal

Chapter 2 – Fundamentals of Laser Tattoo Removal v1.0
Power Density
Power density is just like energy density except it all includes the delivery time or pulse duration. So, it describes the amount of energy concentrated into a spot diameter being delivered in the pulse duration.
Chromophores
Target chromophores will absorb some of the incoming light energy and may heat up as a consequence. In tattoos the chromophores are the ink particles/aggregates.
Photomechanical reaction
In laser tattoo removal the reaction we are trying to induce is the photomechanical (photoacoustic) which is necessary to fragment the ink aggregates.
Absorption
When a photon of light interacts with an electron around an atom, the photon’s energy can be ‘taken’ by the electron causing it to be ‘excited’ – this process is absorption.
Scattering
If an electron has absorbed a photon’s energy, then it will , after a short time, fall back into its original orbit around the nucleus. As it does it releases the energy it took from the photon. If the conditions are right, that energy will emerge as a new photon – this is a scattered photon.
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Chapter 2 LEVEL A Laser Tattoo Removal
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