Page 107 - Chapter 3 - Laser/IPL Hair Removal

Chapter 3 – Fundamentals of Laser/IPL Hair Removal 2nd Edition
Figure 57 - Fluence vs Penetration into the skin
6 J/cm2
Figure 58 - Increasing the fluence at the skin surface will increase the fluence within the skin throughout its thickness
(Note – the values in Figure 58 are not ‘real’. They are merely ‘representative’).
Now, the 4 J/cm2 is much deeper than previously. In this case, the treatment may well be much more successful, since the 4 J/cm2 is significantly deeper than before. This example shows that higher fluences at the skin surface will deliver more energy to deeper levels, thereby increasing the likelihood of success. BUT.... It must always be remembered that more surface cooling MUST be applied when more fluence is applied. ALWAYS!!!
Please note – in the above discussion the numbers are not ‘real’!!! Our calculations have found that the required fluences are higher than those suggested above! Plus, the fluence distribution within the skin is quite complex – it depends on many factors including the absorption and scattering characteristics of the skin layers. Generally, the drop in fluence is exponential, not linear, after a certain depth (See Chapter 1 for more on this topic).
________________________________________________________________________ 107 Chapter 3, Ed. 2.0 Laser/IPL Hair Removal
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2 4 J/cm