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Just TRY and stop me! Please?

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Bearded_Galaxy

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OK, so what's to stop a guy like me from buying a high-powered, IR diode of 808nm, then running it through a frequency doubling crystal to get (darn-close to) BR (404nm vs. 405nm)?
 
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If you used the right SHG crystal, you'd get some 404nm light out, but the stability and beam quality would be atrocious. Direct doubling is extremely difficult to achieve with acceptable results.. Coherent used to have a line of direct-doubled lasers at 457nm (I think). They cost about $50,000 new, and were pretty low powered. This was due to the complexity required to obtain useable output.

The real nitty-gritty about why this is is extremely complicated, but you can find some info in Sam's FAQ (see my sig..)
 
ElektroFreak said:
If you used the right SHG crystal, you'd get some 404nm light out, but the stability and beam quality would be atrocious. Direct doubling is extremely difficult to achieve with acceptable results.. Coherent used to have a line of direct-doubled lasers at 457nm (I think). They cost about $50,000 new, and were pretty low powered. This was due to the complexity required to obtain useable output.

The real nitty-gritty about why this is is extremely complicated, but you can find some info in Sam's FAQ (see my sig..)
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They were at 435nm I think not 457nm. Someone here has one. It would be extremely difficult to make a 404nm doubled DPSS laser. You would need to find a crystal with high conversion efficiency at 808nm. Then you would need to get OC and HR mirrors from somewhere. Control the diode. Control the heating/cooling TEC for the crystal , and align everything up. then get collimation optics.

In all honesty your better using a diode at 405nm.

Regards,

Adam
 
Uhm ..... if frequency doubling was so easy to obtain, i think we may be submersed from beautiful 490nm modules, obtained just doubling cheapy 980nm diodes used in nightvision illuminators ..... :whistle: :wtf:

Ah, well, at least i can always dream, right ? :D
 
To be honest, there seems little point in doing this - if there was any output, it'd be very unstable indeed, and when you can get half a watt from a diode, I really don't see the need. I thought that the main reason for this, though, was that there aren't any known crystals that can FD 808nm with any degree of efficiency (and that it was just fortunate coincidence that allowed us to make 532).
 
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^There are some exotic crystals that can double a very broad range of wavelengths, even 808nm. LiNBO3 (lithium niobate) is one IIRC.. It is temperature dependent, and usually needs to be heated to a specific temperature for whatever wavelength you need.
 
Doubling the output of a laser diode directly simply will not work. The main problem is that the output is relatively broadband (compared to say nd/yag), and doubling requires 2 photos very very close in energy to eachother to work.

So even if you would take a ~1064 nm laser diode (which do exist) and run that through a ktp from a green dpss, it will not work.
 
oh sure it will. I thought it was you but it may be laser ben that has one as stated above.
 
Bearded_Galaxy said:
OK, so what's to stop a guy like me from buying a high-powered, IR diode of 808nm, then running it through a frequency doubling crystal to get (darn-close to) BR (404nm vs. 405nm)?
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youshallnotpassnf9.jpg

YouShallNotPass2.jpg
 
O rly?
 

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ROTFLMAO !

I had to know that, saying something similar, someone already have it or make it, LOL :beer:
 
Bearded_Galaxy said:
OK, so what's to stop a guy like me from buying a high-powered, IR diode of 808nm, then running it through a frequency doubling crystal to get (darn-close to) BR (404nm vs. 405nm)?
Click to expand...

If you think that would work, then what would stop those 404nm from being doubled AGAIN inside the crystal and make 202nm, in it's turn into 101nm, and so on till you get frickin gamma rays?? :eek:

Just a silly theory but you get the idea. :crackup:
 
Well, in fact there isnt anything that 'stops' you from doubling it again, though i doubt that there are crystals that can handle doubling the pump wavelength AND the doubled result. 266 nm lasers are, however, made by doubling 1064 to 532, and doubling again to get 266.

Similarly, 1064 is tripled to 355 nm. This is commonly done by first generating 532 and combining that with the original 1064 (which is possible since they are exact doubles), although it is possible to triple directly to 355 using intracavity non linear optics as well.
 
FireMyLaser said:
If you think that would work, then what would stop those 404nm from being doubled AGAIN inside the crystal and make 202nm, in it's turn into 101nm, and so on till you get frickin gamma rays?? :eek:

Just a silly theory but you get the idea. :crackup:
Click to expand...

HEY ! ..... please, don't share to all the world how i'm making a death ray starting from a blue-ray LD, please ..... it's supposed to be a secret ..... :whistle:

(j/k :D)
 
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