Page 148 - An Introduction to Laser Tattoo Removal

Chapter 2 – Fundamentals of Laser Tattoo Removal v1.0
Hence, for the 1064nm QS pulse at 5 ns,
OD = log10 (12.5 / 5x10-6) = 6.4
and for the 1064nm, 500 ps pulse this is
OD = log10 (12.5 / 3x10-6) = 6.6
Here we see that a 500 ps pulse, which is 0.1 the duration of a 5 ns pulse, requires only a slightly larger optical density to comply with the EN207 standard.
Typically, a laser user would wear glasses with a minimum OD of 7 to protect their eyes properly against these lasers. However, the above calculations are for ONLY the 1064nm wavelength. If other wavelengths, such as the frequency-doubled 532nm line, also require to be filtered, then another calculation must be carried out for the maximum potential energy density of that wavelength!
NEVER use a Q-switched or picosecond laser without the appropriate protective glasses.
And, NEVER look directly into the beam of a Q-switched laser – even with safety glasses!!!
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Chapter 2 LEVEL A Laser Tattoo Removal
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