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I've got a 12" Nd:YAG rod... suggestions?

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[insert obvious joke here]... ;) However - this thing is seriously large. It's 12" long by a little over 3/8" (sorry for the non metrics guys - I guess that's about 30cm x 10mm or something close). It's got a darker purple core and a lighter glass layer surrounding. Mirrored at one end.

Does anyone have any idea what it would take to get this thing to generate a beam? I've had this rod for nearly 20 years now, just rediscovered it while digging out some old test equipment & found it's box.

Ideas, suggestions, ???

Thanks!

D
 

disma

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Heres a suggestion, send it to me! ;D ;D Man that thing will be AWESOME :eek: when you get it built into a laser, the oc end may have a mirror that is only visible to IR... have you looked at it in IR?  :-? The output will be 1064nm IR, and will be MASSIVE! My little 3 inch long yag can blast holes in aluminum foil, and burn stuff very well.Im sure this one would be capable of a lot more!!! The 3 inch rod in the ssy1 is capable of 2 MILLION WATT pulses! :eek: :eek:

Also, if its quite colored, it is a rod ment for flashlamp pumping. You would need to build a photoflash type power supply to flash the flashlamps.

there is a guy on ebay selling flashlamps for 45.00 that would be PERFECT for pumping this rod, you might need 3 for each side of this rod. You need the right kind of flashlamps that produce the corect color pump light. when you get this thing going, post some vids!

Max
 

Greyfox

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That's likely going to push infrared output all right, but it's one heck of a nice rod! Grab a bunch of 808nm pump diodes (or even a flash tube), build up a good, reflective casing with more heat dissipation than you think you would ever need, and find out what this sucker can do. :D
With a rod of that size, it's probably designed to handle output well into class IV. Whatever you do, don't look toward the reflections or even where the beam hits the wall.

Disclaimer: I cannot be held responsible for holes left in your wall by this equipment, either. ;D
 
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Correction and photos....

The long rod is SOLID purple - not glass laminated. I have a few 4" rods that are purple-core, glass laminate. I thought this was of the same stock, but it isn't - this one is solid purple.

Photo number one: The rod posing with my just-today-received Aixiz modules & 2 new LDs, - thank you SenKat! :)

The second photo to follow is looking into the apparently unmirrored (but may be IR mirrored) end of the beast!

Not sure what I want to do with this thing - I know what I have to build if I want to flash-pump this thing... the flash would be visible from the moon and probably trigger some sort of global warning system! :)

Still open to suggestions...

Dave
 

Attachments

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Any chance you know how its doped? Is it meant to be suitable for laser use? If you don't have mirrors for it/on it already, it may get pretty expensive to buy your own :-/.
 
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I know nothing about how it's doped. All I know is it's Nd: YAG and the rest I know from looking at it - so you know as much about it as I do. I bought it from a friend back when I was in college, kept it pristine all these years!

D
 

disma

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I think its definately doped for flashlamp pumping. Although, I dont know if it needs some sort of coating on the outside to be pumped right.

Max
 

disma

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as big as that rod is, it may not need an oc mirror!! Also, from that pic, it looks like the end is definatly coated with something, it may be a reflective coating or may be an ANTI reflective coating... in wich case you need another mirror if the rod isnt long enough to lase. Id get an ssy1 cavity off of ebay for like 50.00 and use the oc mirror from that!

Max
 
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ssy1 cavity? I looked on eBay and was amazed at what's up there - not as expensive as I would have expected.... maybe this thing IS in my range of possibilities. I can mount it in the engine compartment of my car, and... ;D

D
 
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That "Sam's Laser FAQ" thing that I found linked from the eBay listing was worth a look alone! There's some great stuff to be done with these old solid state rods!

D
 

Krutz

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oh gosh! now thats a nice rod!
it definitely is meant for flashlight-pumping. the size is *way* too large and too "uneconomic" for LD pumping. and with that "i got it 20 years ago", i dont really think they had that 808nm stuff back then.. ;-)

unlike with ruby rods, neodynium rods scale nicely. ruby absorbs a lot of its light again on its way. so you have a very high "treshold", and then a high minimum output too. with nd, you could propably use a small (photo-) flash for testing too.

way back then, they thought about measuring the power of a (pulsed) laser in "gillettes", like how many razorblades it punshes. let us know your rating when its done, ok? *party*

oh, the doping is quite different for flashlight and LD pumping, like 0,5% vs 5%, dont remember which was what. but if you have a bag of cheap, weak 808 diodes, or want to play with those awfully large 808nm arrays noone has a use for, it should put something out too.. hehe
yes, the more i think about it, try a long 808nm array, which are hard to work with in normal applications, but you could really use that long strip of IR..

whatever you do, dont set yourself on fire, and post it here!

manuel
 

Krutz

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me wrotes:
Krutz said:
...or want to play with those awfully large 808nm arrays noone has a use for, it should put something out too.. hehe
coincidently i found what i meant at ebay today:
http://cgi.ebay.de/Coherent-Laser-D...ryZ53141QQrdZ1QQssPageNameZWD2VQQcmdZViewItem

and the same, but more expensive:
http://cgi.ebay.de/COHERENT-VERY-HI...ryZ92078QQrdZ1QQssPageNameZWD2VQQcmdZViewItem

its ebay germany, but would ship anywhere.
50 watts 808nm array, with a 18mm (5/6 inch) "beam". still some magnitudes smaller than your long rod, but i guess it would still work. since the neodynium wont absorb much of the 1064, it shouldnt harm much. but perhaps the smaller rods you mentioned would be a better choice, although they are thin and laminated.
anyway, you wont really get it portable, it needs watercooling and up to 60 amp.
watercooling: no big deal, really small self-constained setups are in computers, you could build it into a shoe-box, with integrated chiller and everything, 12v driven. only those 60 amps will be tricky to get portable.. ;-)

i wonder what happened when you shine 50 watts on a side of the rod.. powerdensity will be enormous, but how much loss from spontaneous emission which goes right through the rod in the wrong direction will happen? once laser-oscillation starts, loss could be pretty small? anyway, i would recomment *slow* start of the diode, since the thermal stress would surely scatter the rod instantly!

uhm, anyway.. there you have my mentioned monsterarrays! :)

manuel
 

Cyparagon

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You could get a concave lens for just one dimension, and make the beam longer
 




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