To the Ar vs As controversy, I'd say that on any other forum people would have written it off as a typo, but given that earlier in the thread we were discussing gas lasers and that Argon is a very common lasing medium I think it's understandable that people thought you really did mean Argon. No harm no foul though.
Ah, I think you may be confusing two very different technologies here. Let's back up a bit:
YAG (Yittrium-Aluminum-Garnet) is a glass-like substrate that is used in solid lasers which are optically pumped (either by a flashlamp or by a diode array). The "dopant", or impurity that is added to the YAG is the stuff that actually lases. Neodymium is one commonly used dopant; Vanadate is another. Both will lase at 1064 nm (and a bunch of other IR wavelengths as well, though 1064 is the strongest line). The YAG and the dopant are melted in a crucible and a boule is formed around a seed crystal that is inserted and then slowly withdrawn from the molten mixture. That is polished into a rod, which goes into a cavity to be pumped.
Note, however, that there is only 1 dopant added, and it is incorporated into the YAG crystal lattice as a bunch of interstitial point defects that are more or less evenly distributed throughout the material. Also, the presence of the dopant does not alter the conductivity of the crystal in any meaningful way.
Conversely, a laser diode is electrically pumped and uses two different dopants to change the base crystal (usually Gallium-Arsenide) into a P-type semi-conductor on one side, and an N-type semi-conductor on the other side. The P-N junction area where the two different types meet is where lasing action takes place. These diodes are made in a molecular deposition vacuum chamber by first building a substrate of GaAs and then masking off parts of the substrate before adding the P-type dopant (to form 1/2 of the diode), then masking the other side before adding the N-type dopant.
So the crucial difference is that when building a YAG laser crystal you add the material you actually expect to do the lasing (and nothing else), while in a diode laser you need two different materials (only one of which will ultimately be lasing). Thus it doesn't make sense to talk about P and N type dopants with regard to YAG lasers.
The kiln should get you up to the temperatures you need to make your own YAG crystals, and yes, you can experiment with different dopants, but remember that the resulting boule is *not* suitable for lasing. It will need to be ground and polished first. This requires a good bit of lapidary equipment and expertise. (Just a warning.)
Well, yes, it is. But there are some things that are just not worth doing yourself. Case in point: people built their own planes, but they very rarely build their own engines. They buy one off the shelf. What you are describing is akin to someone purchasing a solid block of aluminium and machining their own engine block from scratch. It is technically doable, but it really doesn't offer any benefit over buying the block already machined for you.
I'm not aware of any direct-injection diodes that lase at 1064 nm. All of the solid lasers that output 1064 nm light are optically-pumped, at least to the best of my knowledge. (This ignores the chemical gas lasers we discussed previously.)
However, there are several solid medium lasers that output 1064 nm light at very high energy levels. Diode-pumped medical YAGs probably top out at around the 400 watt level for IR at 1064 nm, and I'm sure there are industrial solutions that go higher. These typically run on 208V 3 phase at 30 amps per leg, which is roughly equivalent to your 220 volt single phase at 50 amps example.
Furthermore, the military has pushed this design up to at least 50KW, based on recent news reports, and I don't think they've reached the limits of the technology yet. So it's conceivable that a dedicated hobbyist could reach multi-KW outputs with proper engineering and quality optics.
Basically what we're saying is, "Why re-invent the wheel?". Now, if the goal is just to have fun, experiment, and maybe learn more about the underlying physics, then that has value in itself even if you don't hit your target. But if you want to be sure it will work, start with proven technology. You'll get to the finish line faster, for less money.
Some of the replies in this thread have been quite technical. Remember that threads are forever. Someone down the line may be thinking about a similar approach, and if they find this thread they might learn something from what we are discussing today.
And yet there are lots of people who would be interested in such a thing. I think there is value in explaining why a light saber (as depicted in the movies) is not possible. Sure, some people will tune out as soon as they learn it's pure fantasy. But some people will stick around to learn about *why* it's not possible, and even stick around to learn about other things that could be done. Those people are the next generation of laser enthusiasts.
And yet no one has taken up the challenge. Lycoming engines are pricey, but they don't sell nearly as many engines as GM does either. Then there's the liability issue with anything that is flight-rated.
I think the only way it would work is if someone had access to a commercial-grade CNC mill (and all the tooling) and there were no cost or time constraints.
Go back to the 1940's when plane crashes due to mechanical failure were more common and you begin to understand the current regulatory climate surrounding all things aviation. I don't disagree that it's worth having the discussion about monopoly powers in aviation, but you do have to acknowledge that there are sound reasons for the rules we have today. Most of them are written in blood.
Can't argue with you there.
Adam