Question: How powerful are your lasers?

Thomas Elias Cocolios answered on 13 Mar 2014:

We have a big suite of lasers in ISOLDE (I just counted 15 from memory!) and the power we use depends largely from the application.

The most powerful lasers we have are the Nd:YAG lasers, which are used for ablation, brute force ionisation and giving power to the other lasers. We reach up to 100W in those lasers. They however only operate in the infrared at 1064 nm, and with special optical elements, also at 532 nm (bright green, like a pointer) and 355 nm (ultraviolet).

After that, we have the Titanium:Sapphire lasers and dye lasers, which are used to produce laser light at any frequency you need. You send the big laser power in the sapphire crystal or in the liquid dye, excite the crystal/molecules, and those produce light in specific ranges. The typical power output is 10W. Those system are very nice to produce red light, but not so good at yellow, green or blue.

What you need to do then is to process the light through a non-linear crystal: the laser comes in, excite phonons in the crystal (and yes, not photon, phonon!) which may emit a photon with twice the frequency / half the wavelength. The process is not very efficient and you end up with <1W of green/yellow. For the ultraviolet and blue, you need to triple or even twice double the frequency and that is even more costly in power (~10mW). You have however so much energy (the higher the frequency, the higher the energy) that your excitation works much better and you do not need more power than that!