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FrozenGate by Avery

561nm crystals






Cyparagon said:
But any Nd:YAG will do 1123 with the proper mirrors, yes? The coated KTP is what made this purchase desirable?
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Yes, though it won't usually be as amplified. the main lasing wavelength is for 1064nm as I'm positive you know, and like all lasing mediums, when excited, they emit all their wavelengths at once, in a relatively set amount. for example all HeNes are lasing all their wavelengths at the same time, but the mirrors are what determine the wavelength that is amplified and comes out. Same applies to Argon Ion lasers, etc. (not counting other little factors like fill pressure and such that can also be tweaked to optimize a particular line) Nd when pumped by 808 in particular lases several lines, 1064 is just the greatest in emission, and therefore is the most efficient and common. But by changing the peak reflection you can select other spectra that are being emitted, dependant on the dopant level. lower gain lines often have a slightly higher dopant level. but by including more Nd in the lattice, the harder it is to get it saturated, because the absorption takes place faster.

Cyparagon said:
Side-question, would a regular KTP with standard coatings double 1123nm?
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The simple answer is yes in theory. the realistic answer is a bit more complex. coatings have a 'curve' at which they are reflective (or not). it would depend on what coating existed on the KTP already. often like HeNe mirrors or anything else, they are optimized for a particular wavelength, rejecting or passing the others. in this case you'd have to look at the coating's AR curve and see how much 1123 it would pass. (a similar principle can be used for seeing how much gain you could get using the 1064 mirrors at 1123 above) if it passed enough of it to still overcome the losses already being incurred that you could get enough gain to start the harmonics so the 1123nm photons were interacting with each other, then yes you could use it. The crystal lattice is still going to function the same. if you could get enough 1123nm photons going through it it would double them the same as any other photon the crystal is transparent to. This is one reason I liked my KnBO3 lattice until it cracked. It's transparant to all visible light, so with a broadband coating and a higher nonlinear coefficient, it'd double anything I sent through it as long as I had the right mirrors, but they're also far harder to produce, especially in large sizes. (hence why they're much more pricy than say a KTP)

Edit: Basically the crystals are just optimized for this particular process, but they could still in theory be used for other processes. A good example of this is my yellow realignment here where I demonstrated pulling green 532nm out of the yellow cavity. I did it with the same yellow mirrors and such, I didn't use anything extra. I simply tweaked it so that the losses at 1319 were too great and it stopped resonating, leaving only the 1064 to be doubled, though inefficiently, giving me green in the yellow cavity.
 
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