When photons (light) enter the skin they can undergo only two processes – absorption or scattering. Once a photon is absorbed, its energy is ‘gained’ by the absorbing site. This may be a melanosome in the epidermal basal layer (see figure 1 – ‘Epidermal absorption’). This absorption will transfer the photon’s energy into the melanin… Continue reading Where do photons go in the skin?
I read an interesting paper on this topic, last week. It was a clinical study looking into the application of ‘super hair removal’ using a low fluence output from a diode laser. As you may already know, I’m not a big fan of this technique. I feel that it is ‘tricky’ to administer properly and… Continue reading SHR/In-motion tehcnique – an update
Here’s a strange thing…. When we fire a laser or an IPL at the skin surface we usually know the fluence that is applied. So, we figure that a 10 J/cm2 will penetrate into the skin and diminish with depth. Well, bizarrely, it doesn’t!! This is entirely due to scattering. So, what is scattering? The… Continue reading How can there be more fluence inside the skin than is applied at the surface???