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Would it be possible ?

brendon7358

brendon7358

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DPSS green lasers are made with an IR diode then a crystal which makes it green and reduces the power for instance a 1W IR diode would make a 100-200mw green laser so how powerful is the IR diode in a cheap 5mw ebay one ? Could I possibly remove or break the crystal and have a 100-200mw IR laser which could burn stuff ? I do not plan on doing this it's just a theory. I already have a 200mw green laser for burning stuff :thanks:
 





Sigurthr

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Yeah it works, but it is incredibly dangerous without laser goggles made for IR.

Back when WL first released their CORE series, I got one free from a contest and one I bought. The one I bought still works fine today, the free one died in about 10mins. I just removed the nonlinear cavity (the part containing the crystals) and used it as a night vision illuminator. It won't be focused though, so keep that in mind. Most 5mW pens tend to have around 200mW of IR pumping them, depending on efficiency it could be more or less.
 
Tech_Junkie

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No it would not work. You'd need to focus the beam to burn things. You'd have to pop the diode out and place it in a module with a focusing lens. You'd be better off buy a 1W IR diode, and a 9mm module.
 
Eudaimonium

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Sigurthr said:
Yeah it works, but it is incredibly dangerous without laser goggles made for IR.

Back when WL first released their CORE series, I got one free from a contest and one I bought. The one I bought still works fine today, the free one died in about 10mins.
Click to expand...
tumblr_ly621dbDy11r5zug6.png

Sigurthr said:
I just removed the nonlinear cavity (the part containing the crystals) and used it as a night vision illuminator. It won't be focused though, so keep that in mind. Most 5mW pens tend to have around 200mW of IR pumping them, depending on efficiency it could be more or less.
Click to expand...
Why would a 5 mW laser have a 200mW pump in it?

I think most have 30mW to 50mW pump diodes, judging from the current drawn. I don't think they can be overdriven to 200mW.
 
Cyparagon

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All the 5mW pointers I've had have operated at >150mA. That seems indicative of a 200mW pump to me. Remember that the DPSS process is less efficient at lower powers.
 
Sigurthr

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Yup, the pump diode has to be high enough power to go through two inefficient crystals; first to 1064 and then halved to 532. I don't know typical/actual efficiencies but they're not high at all, probably something like 10% makes it to 1064, and then maybe 45% of the 1064 makes it to 532nm.
 
Eudaimonium

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Hmm, I guess I was unaware of that.

Thanks, guys.

But anyway, point still stands - it's not worth taking apart a 532nm laser to get IR diode to use as a burner.

There are much better alternatives.
 
Hiemal

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What happens out of curiousity if you take out one of the crystals?

Would the output wavelength be lowered, or would the doubling crystal not work any more?
 
Sigurthr

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If you remove the 1064 crystal but not the KTP you'll get 808nm hitting the KTP, and KTP doesn't respond to 808nm (otherwise we would have 404nm DPSS). The coatings on the KTP may reflect the 808 and you'd possibly destroy your pump with internal reflections. If you remove the KTP then you have a 1064nm DPSS laser.
 
brendon7358

brendon7358

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Eudaimonium said:
Hmm, I guess I was unaware of that.

Thanks, guys.

But anyway, point still stands - it's not worth taking apart a 532nm laser to get IR diode to use as a burner.

There are much better alternatives.
Click to expand...

It may not be worth the effort but it is a much better alternative to potmodding :eek:
 
Sigurthr

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Not only 1064, there are other freqiencies... I don't know them though.
 
Cyparagon

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Sigurthr said:
If you remove the KTP then you have a 1064nm DPSS laser.
Click to expand...

You would no longer have a cavity. Most lasers require mirrors to operate. Coatings on the crystals act as mirrors. If you remove a crystal, you remove coatings which will probably render both crystals useless without an additional cavity setup.
 
Sigurthr

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Actually, I think you're right, Cyparagon. You'd at best have a dim 1064nm LED, and that would only happen if the crystals weren't combos like most use now.

Though it is possible that the 1064 crystal could be coated:
808 ---> HT808/HR1064 | crystal | HR808/OC1064 ---> 1064
 
Benm

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Thats possible in theory, but all practical green laser pointers use intracavity doubling, so removing the KTP crystal would also remove on of the 1064 nm cavity mirrors.

As for being able to convert a 5 mW green pointer into a 100-200 nm 808 nm laser: yes, that is feasible. As stated you would need to adjust or replace to optics to get a paralel beam out of it (which would be of mediocra quality since the pump diode is multimode).

I dont think it would be worthwhile though - you can purchase a 200 mW single mode red diode for under $10 that would yield much better beam quality and a visible beam as a bonus.
 
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