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 Post subject: Synthetic Ruby Laser Rod
PostPosted: Mon Oct 22, 2012 7:49 pm 
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Location: Glendora, CA 91741
I am working on a post loss appraisal report that includes 3 synthetic Ruby laser rods. My questions are:
1) Does anyone know of a legitimate secondary market for synthetic laser ruby rods?
2) Does the diameter or length of the rod affect the value?
3) At what temperature will the laser rod become compromised? (The loss involves a fire)

Thanks!
Teri

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Glendora, CA 91741

626-335-6002 or 951-237-6005


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Mon Oct 22, 2012 8:15 pm 
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Precisely how were these laser ruby rods going to be used? What was their intended purpose?


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Mon Oct 22, 2012 8:32 pm 
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The only information I have to go on is:

1) megawatt ruby laser with 6 inch x 3/8 inch ruby
2) holographic ruby laser with 3 inch x 3/8 inch ruby
3) 6 inch x 5/8 inch synthetic ruby (used for gemstone faceting)

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Theresa L. Newman Brossmer, G.G, ASA
www.gem-appraisals.com
Gem Appraisals Unlimited, LLC
158 No. Glendora Ave. #K
Glendora, CA 91741

626-335-6002 or 951-237-6005


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Mon Oct 22, 2012 11:37 pm 
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Probably actually 10mm for the 3/8 inch.

The question is , was it a theft loss. In laser use these are exposed to vigorous conditions
intense light which can be accompanied by heat. In order to get the most power out of them they sometimes push them to the bleeding edge of what is possible. Then add to that that most ruby lasers are operated by high tech types in the extreme and you have to consider the possibility that someone put a brick on the accelerator.

Which means NO recovery for cracks nor for damaged end surfaces or coatings. Those are the reasons that the real ruby laser users end up putting these on the market. They don't usually come to gem and jewelry collectors unless the lasers they work in are no longer usable for some reason.

I myself have been trying to get my hands on just such ruby laser rods as I mentioned not very long ago. 10 mm rods are not common but you do see them. Even in six inch length. I have never seen 5/8 inch rods on ebay. faceters do seem to be willing to pay for these because they are totally transparent and most of the ones I have seen had a very nice ruby color and looked like they would cut behind kicking gemstones.

If they were laser rods then at least you have some sort of standard to compare too. Internally flawless and bright red color with fluorescence most likely.
On the other hand your problem in assigning a value is how much could I get another one for. My thought after watching ebay for years is that they probably could be replaced for 200 to 400 dollars. There was a guy recently who was offering some big blocky chucks of about 50 carats for 250-400 US buckarinos.

Newly made laser rods are expensive. They only get out of the factories they lase in when they are not worth reworking or the laser that they go in is otherwise decieased.
The main value is in grinding them into rods and making the end faces perfectly parallel or perfectly whatever. And possibly some fancy damage resistant coatings. When this is not reworkable they get tossed to the gem cutters. They are usually Czochralski pulled crystals I believe but there have been many synthetic corundum processes. I think even annealed Verneuil has been done.

You might find replacements with pricing at used laser places. You could also ask at some of the places that grow crystals for gem cutting.

http://www.chatham.com/Contact_Us.php

http://www.shelbygemfactory.com/

A bigger obstacle is that any gems cut from these rods, although they might be eye pleasing , they won't have much value. $10(cut stone not rod) each might be generous.


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Tue Oct 23, 2012 12:18 am 
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Thanks for the great info. The loss was sustained in a fire. The description is courtesy of the claimant, thus the lack of detail. I have emailed Chatham and Stone Laboratories and will contact the other manufacturer tomorrow. Thanks again, Teri


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Tue Oct 23, 2012 2:06 pm 
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Might be hard to distinguish between damage caused in a fire and damage caused by use as a laser.
Also hard for me to imagine a fire using atmospheric air getting hot enough to really damage a corundum unless it was at red heat and a fire hose deluged it which could have caused "crackeleur" type of damage. Corundum is extremely refractory and is usually durable to torch repairs iirc.


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Wed Oct 24, 2012 2:12 am 
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Terigem wrote:
The only information I have to go on is:

1) megawatt ruby laser with 6 inch x 3/8 inch ruby
2) holographic ruby laser with 3 inch x 3/8 inch ruby
3) 6 inch x 5/8 inch synthetic ruby (used for gemstone faceting)


After reading this post, something has been nagging at me, but I couldn't pin it down. Then it hit me. Laser rod (1) has been extremely mis-characterized.

The watt (W) and its multiplier megawatt (MW) is a unit of power used to characterize the output of a laser that produces a continuous beam. A typical industrial cutting laser puts out tens of watts of power. Any laser putting out megawatt power would be an extreme danger to itself and anything nearby. Think of the laser in the movie "Real Genius" that ablates a hole through anything in the beam's path before it destroys itself.
Attachment:
real genius.jpg
real genius.jpg [ 10.6 KiB | Viewed 4697 times ]

However a ruby laser produces a pulsed beam. Pulsed beam output is measured by the energy contained in an output pulse, in units Joules (J). Ruby lasers tend to have outputs in the range of millijoules (mJ), thousandths of a joule ... not megajoules, thousands of joules.

Most likely the rod should be described as a millijoule laser rod, not a megawatt laser rod.

In contrast, due to their pulsed beams, ruby lasers are quite useful for making holograms. So I believe the characterization of laser rod (2).

Finally, I've never seen or read about a ruby laser rod with 5/8" diameter. All the rods I've seen are 3/8" diameter. But that doesn't mean the larger diameter doesn't exist. I'd imagine gemcutters would be quite interested in those rods.


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Wed Oct 24, 2012 10:38 am 
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Quote:
Most likely the rod should be described as a millijoule laser rod, not a megawatt laser rod.


Six of one, half dozen of the other. 10 millijoules for 10 nanoseconds is a peak power of 1 Megawatt. Megawatt lasers are not at all uncommon.


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Wed Oct 24, 2012 1:30 pm 
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Ruby laser pulse duration is on order of 1 millisecond, not 10 nanoseconds. Must be one very bright flash lamp feeding the ruby laser, putting over a Joule of energy. But, point taken... it is within the realm of possibility to describe a ruby laser as megawatt.


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Wed Oct 24, 2012 1:47 pm 
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An item of interest from U of R:
"OMEGA's 60 laser beams focus up to 40,000 joules of energy onto a target that measures less than 1 millimeter in diameter in approximately one billionth of a second."

Hardly your typical benchtop laser :-)


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 Post subject: Re: Synthetic Ruby Laser Rod
PostPosted: Wed Oct 24, 2012 4:29 pm 
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Yep, that is more the kind of MW lasers I was thinking about.


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