[Laser] Re: Laser Rod

[Tim Toast]

Those might be Neodymium-YAG rods if it was an older 
range finder. Those emit at 1.06 micrometers 
(1064 nm). If it was a newer one then it might be one 
of several types that emit at 1.4 um and longer 
wavelengths including Erbium-glass, which emits at 
1.54 micrometers. Wavelengths longer than about 1.4 
microns are considered "eye-safe" in that the light 
doesn't penetrate into the eyeball very far. So they 
are used relatively safely in modern low power 
rangefinders. 
i saw several of the rods on e-bay including some 
ruby types - polished and ready for experimentation. 
One of the rod auctions said theirs was used with a 
flashtube pump energy of only 5 J. For comparison, 
most camera flash tubes put out 10 Joules or more. 
Although present-day Led's probably couldn't pump 
any of these rods, some smaller ones are meant to 
have IR laser diodes pump them with as little as 100 
milliwatts.
some fun dpss info:
http://repairfaq.ece.drexel.edu/sam/lasercds.htm

>
>I saw an ad in Electronic Goldmine for the rods from 
>a military laser range finder. I think it said that 
>they were pumped by flash tubes. The thought came to 
>me that if it was build to be "pumped" by a flash
tube, 
>would white LEDs provide the stimulus easier and
cheaper 
>than a flash? I really don't know about such things,
but 
>I thought it would be worth posting. 
>James N5GUI 



Tim Toast
http://www.aladal.net/toast/exp.html


		
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