Page 141 - An Introduction to Laser Tattoo Removal

Chapter 2 – Fundamentals of Laser Tattoo Removal v1.0
Appendix 3 - Calculating the Fluence (Energy Density)
Knowing the fluence (or energy density) is very important in laser skin treatments. It is, therefore, important to know how to calculate the fluence you are applying to the skin surface. (What is fluence again?)
The following video may help....
Figure 68: What is fluence?
To calculate the fluence of your laser you need to know two things:
the energy in your pulse, ‘E’;
the spot diameter on the skin surface, ‘d’.
The first of these must be measured using an appropriate meter – there is no other way of doing this!
The second may be found by firing the laser energy at a dark piece of paper or laser burn paper. This should generate a burn pattern which can be measured.
Once you know these you can then calculate the fluence by dividing the energy, E, by the sport size area, which is π (d/2)2 or πr2 (where ‘r’ is the radius).
Note: it’s a good idea to convert any spot size measurement into centimetres!! ________________________________________________________________________ 141
Chapter 2 LEVEL A Laser Tattoo Removal
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