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Look at this DPSS crystal!

Misanthrop

Misanthrop

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This is two crystals from a 532 DPSS system, I can't remember the names of the crystals, but I think it's definitely an 808 system....

With the purple crystal doubling and the green hueish halving it.

Basically the crystal on the bottom with the purple coated sides just looks a bit odd to me, like the whole thing should be purple rather than just how it is below with those weird yellow bits around it like a halo.

Then you have the one on the top which has a slightly green hue to it, that may narrow it down for someone who knows their crystals.

I'm going to try a few things with them but I need to know if that crystal has or hasn't deteriorated, I've tried shining an 808 through them both with no results, and I didn't have enough time to do any alignments properly before I broke the IR pen I had :yabbmad:

I'm just wondering if this looks familiar to anyone who's had problem's with these crystals before, and where I could possibly get another in the same dimensions if it comes to light that it's deteriorated.







 
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E

ElektroFreak

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The thin square crystal with the circular coating on it is Nd:YVO4, which is pumped with an 808nm diode to produce 1064nm output. The larger crystal with the arrows on it is a KTP doubling crystal. This takes 2 1064nm photons and combines them into one 532nm photon, producing green output. Both of your crystals look good based on these pics, but there is some graininess so I can't pick out fine details. As far as sources go, I'd check o-like.com and ebay seller "snoctony".
 
rhd

rhd

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ElektroFreak said:
The thin square crystal with the circular coating on it is Nd:YVO4, which is pumped with an 808nm diode to produce 1064nm output. The larger crystal with the arrows on it is a KTP doubling crystal. This takes 2 1064nm photons and combines them into one 532nm photon, producing green output. Both of your crystals look good based on these pics, but there is some graininess so I can't pick out fine details. As far as sources go, I'd check o-like.com and ebay seller "snoctony".
Click to expand...

That's conceptually difficult for me to understand.

It seems like it should take 1 1064nm photon and split it into 2 532nm photons.
 
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Shadow187

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You're combining two photons to make one with twice the energy, twice the frequency, and therefore, twice the wavelength.
 
Ablaze

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_____/\______/\______/\__ <--- dist between = 1064
+
_/\______/\______/\______
=
_/\__/\__/\__/\__/\__/\__/\ <--- dist between = 532
 
qumefox

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Just 'shining 808nm' at these isn't going to get you anywhere. You need both crystals, as well as OC and HR mirrors (though the rear face of the gain crystal is probably HR coated) all precisely aligned to form an optical cavity before you get any green light out. When dealing with two part crystal sets, the complexity goes WAY up compared to the cheap bonded crystal pairs that are basically 'standalone' and only require being pumped.
 
Ablaze

Ablaze

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qumefox said:
When dealing with two part crystal sets, the complexity goes WAY up compared to the cheap bonded crystal pairs that are basically 'standalone' and only require being pumped.
Click to expand...
May I quote you in the "how to start a threesome" thread? :p
 
Cyparagon

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Why don't you join me instead?

it-pennywise-basement1.jpg
 
E

ElektroFreak

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rhd said:
That's conceptually difficult for me to understand.

It seems like it should take 1 1064nm photon and split it into 2 532nm photons.
Click to expand...

As wavelength decreases, the energy per photon increases. When a doubling crystal acts on incoming light, it combines two photons with x energy into one photon with 2x energy and half the wavelength.
 
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ElektroFreak

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qumefox said:
Just 'shining 808nm' at these isn't going to get you anywhere. You need both crystals, as well as OC and HR mirrors (though the rear face of the gain crystal is probably HR coated) all precisely aligned to form an optical cavity before you get any green light out. When dealing with two part crystal sets, the complexity goes WAY up compared to the cheap bonded crystal pairs that are basically 'standalone' and only require being pumped.
Click to expand...

True. This thread really helps lay out the basic requirements of discrete crystals:
http://laserpointerforums.com/f45/do-yourself-complete-green-dpss-o-like-crystals-42495.html
 
Misanthrop

Misanthrop

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qumefox said:
Just 'shining 808nm' at these isn't going to get you anywhere. You need both crystals, as well as OC and HR mirrors (though the rear face of the gain crystal is probably HR coated) all precisely aligned to form an optical cavity before you get any green light out. When dealing with two part crystal sets, the complexity goes WAY up compared to the cheap bonded crystal pairs that are basically 'standalone' and only require being pumped.
Click to expand...

I was using both crystals, this is out out of a labby and I took the head off so I could shine the 808 through them both when they were in place, obviously as you said I need to move them around to a precise point.

I'll just have to wait for that lazerer 2W to come before I can mess around with them.
 
qumefox

qumefox

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You probably would have had better luck had you left them in the housing they were in with the optics they had. When you took them out, you made things REALLY hard on yourself. For DPSS to work, you pretty much need the alignment of all the components of the system almost in perfect alignment to get anything out of it. Otherwise the optical losses will exceed the gain you get, and you get nothing.
 
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ElektroFreak

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Yeah he'll probably be aligning for a good while, but that's actually a good thing just for the learning experience. Typically when I replace a pump diode I leave everything about the crystal set exactly as it was from the factory. That way all I have to do is adjust the pump diode for the best output.
 
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