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FrozenGate by Avery

cheap laser rod






I think Erbium is about 2630 nM IR. Considered "eyesafe???"
You would need cavity mirrors and those scratches / chips could kill the rod with the first shot. That's why it's cheap.

Mike
 
Hemlock Mike said:
I think Erbium is about 2630 nM IR.  Considered "eyesafe???"
You would need cavity mirrors and those scratches / chips could kill the rod with the first shot.  That's why it's cheap.
Click to expand...

The reason for the erbium rods being considered eye safe, is because they don't focus onto the retina. If memory serves, the wavelength in question is absorbed by water, which would heat the vitreous humor. FrothyChimp made a post about it a little while ago. Since the light is significantly absorbed before reaching the retina, and not tightly focused by the lenses in the eye, you need more energy to cause retina damage. The vitreous can handle a lot more heat than the retina, among other things because the blood supply will act as a fluid cooling pump. UV light gets stuck in the lens parts of the eye, causing cataracts and such, so are equally harmful, per se, but again not as sharply focused.

That said, the depicted rod will produce a lot of power in a cavity, if fully pumped. I suspect it will be more than enough to cause serious damage. I wouldn't want it on my skin, to put it that way. Seems to me it would be similar to sticking your hand in a microwave, given that it heats the water in your cells. I believe it has been used for soft tissue surgery by dentists, and vaguely recall WP mentioning something about cutting bone with it. Certainly not an item to be playing around with.

As for the chips, a skilled stone cutter with a diamond wire saw and knowledge of the properties of the crystal should be able to replicate the brewster angle cut, albeit probably with less precision than the factory. Polishing wouldn't be as fine, either, but I think you could still make the thing lase. The cheapest option might simply be to ship it to a manufacturer that does refurbishing of old rods instead. They have the experience and equipment to deal with it. The chip is probably less of an issue than the implications for the rest of the surface. It may have small fractures. If it's a clean chip, though, a concave mirror can be used for the cavity to minimize the amount of feedback delivered around the area of the chip, which might allow you to use it.

I'm way out of my depth here, though.

And I suspect whoever buys the rods will be, too.
 
I purchased one a while ago just to have, but now that im getting into lasers allot more i'm thinking about building a laser around it. Any one got any ideas what this could run me for costs? the rod i got only has chips on the ends.
 
If the ends are chiped then the rod is junk.
Also, you will need 2 mirrors, a high reflector (reflects 99.999%) and an optical coupler (reflects about 80-90%). The mirrors need to be dielectric type designed specially for the laser wavelength.
Even if you have a good rod, mirrors for the Erbium are rare, as in never seen surplus mirrors.

I would suggest you order from here a yag laser:
www (dot) mi-lasers (dot) com/cgi-bin/shopper.cgi?search=action&keywords=yag_lasers

You will need the SSY1 frame, cavity, rod and flash lamp as a minimum.

However, unless you are experienced in electronics I would advise against it. The main capacitor can and WILL kill you if you get electrocuted.
Compared to the capacitor sock, the wall mains are rather "safe" !

If you want to see it in action, mine:
www (dot) youtube (dot) com/watch?v=3UhWxXMht8I

frothychimp's:
www (dot) youtube (dot) com/watch?v=vJGxT2E1Bhk
 
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