Page 126 - Mike Murphy's Blog Posts

B4 - Are picosecond lasers worth the cost?
That's a good question!
A picosecond laser costs around £100,000 in the UK, at the moment. A 'standard' Q- switched laser costs anywhere between £10,000 and £60,000.
QS lasers can output up to 2 Joules of energy in pulsewidths as short as 5 nanoseconds, while some commercially available pico lasers can output up to 1 Joule in 0.35 nanoseconds (or 350 picoseconds, as they like to say!)
So, what exactly are you paying for in a pico laser?
Well, some manufacturers claim that they are "better" are removing difficult colours, such as yellow, green and light blue. However, they use the same wavelengths as found in QS lasers - 1064, 755 and 532 nm. Given that the absorption efficiency of any coloured ink depends on the wavelength (NOT the pulsewidth) I can't see why a laser with a shorter pulse but using the same wavelength would be any better at removing these colours! Unless you know better?
I've heard some nonsense about QS lasers generating photothermal reactions compared with photomechanical (or photoacoustic) reactions generated by pico lasers. This is complete rubbish!! Both types of laser will generate photoacoustic reactions on ink surfaces (I will explain this in much greater scientific detail soon).
Mike’s Blog Posts 126