Someone recently asked me ‘which is the most aggressive wavelength for the skin?’ That’s interesting question… We should first start by identifying which wavelengths we need to consider. In many skin treatments we use visible and near-infrared light – from around 400 nm up to 1064 nm (Nd:YAG) or even 2940 nm (erbium:YAG). CO2 lasers… Continue reading Which are the most ‘aggressive’ wavelengths?
Tag: tattoos
PMU inks – what is in them?
I recently came across an excellent book called “PMUni Colourant Manual” by Jasmine Diebelius which delves into the world of PMU inks and their constituents. In it, she indicates the pigments used to formulate many commonly-used PMU inks. This has proved very interesting to me, because of the ramifications for laser removal. In one section,… Continue reading PMU inks – what is in them?
Human retinal sensitivity to wavelengths
Most people can see a wide range of coloured light, from around 350 up to 750nm. But, our sensitivity is not the same for all colours. Our human retina sees different colours differently. The graph below shows how this is – we see violet very poorly. Likewise with the ‘deep’ reds, out at 700+ nm.… Continue reading Human retinal sensitivity to wavelengths
The WRONG way to do laser tattoo removal!
It appears many people are using their tattoo laser wrongly! They are holding it off the skin, up to 10 to 20cm away. This is just wrong!! By doing this they will invariably apply a very small spot diameter at the skin surface which generates a huge fluence (energy density). Such fluences can easily damage… Continue reading The WRONG way to do laser tattoo removal!
Experiments with India ink and a Q-switched Nd:YAG laser
What happens when India ink absorbs laser energy? I irradiated some dry India ink trapped between two glass slides here (the ink was allowed to dry overnight). I used 5 J/cm^2 with a 1064 nm wavelength. As you can see, the laser energy ‘vapourises’ the ink and leaves voids behind. But, very little ink leaves… Continue reading Experiments with India ink and a Q-switched Nd:YAG laser
Mike Murphy's Blog 