Rubies and high powered lasers....

[PyroEric]

I have a number of large 16mm diameter rubies from when my ex was on a homemade jewelry making kick, have 9 of them left. One was cut really poorly so I played around with it underneath the 20" x36" fresnel lens on a bright summer day.

The shape of the cut tends to act like a lens, making a tight point of light at the back of the gem, and with the fresnel lens it produced a very tight narrow heating spot, burning a hole in the 2800 degree refractory cement brick it was laying on.

At around 3000 degrees they glow so bright that you cant look at them even from a long ways away, once they cool to the point where they dont glow, they appear dark black, once they cool more they go back to the normal red. Heating them up that high can cause cracks to form.

I also played around with them with the 5mw red pointers I have but was wondering if anyone has experimented with rubies and 200-300 mw red lasers. It would be interesting to see if they convert more of the lasers output into IR.

They are lab rubies, NOT simulated rubies, they are chemically / atomically exactly the same as real rubies except for the fact that they have no flaws and are more or less optically perfect.

If you have some diamond grinding bits for a rotary tool you can grind them into lenses ....

 

[Viracocha]

I thought laser rubies had been doped with something to make them lase and the ruby itself was only the carrier, like the yag crystals in green lasers?

 

[FrothyChimp]

The dopant for ruby laser is chromium. Chromium is what gives ruby it's red color. Without it would just be a clear sapphire. Sapphire is the substrate material just as it is in YAG. Neodymium gives sapphire the pinkish purple color while chromium makes it red.

 

[Switch]

This is really interesting.Do they glow without exposure to light until they cool down? :-? What's that phenomenon called?

I have a piece of raw chromium ore(i think).It fluoresces a pinkinsh red colour under the bluray.Better viewed with goggles because it's pretty dim.

Gotta find some jewelry and shine lasers at them
Why would it convert red to IR? I guess I could check that with a camera, but it's gonna be hard finding a filter that blocks red , yet passes IR.Probably nothing household. :-/