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ArcticMyst Security by Avery

Yellow 573nm DPSS Laser Modules

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Anyone have any thoughts on how the 573nm process works? Possibly directly doubled from 1146nm?

I took my module apart to see whats inside. The aluminum section is threaded onto the brass base with glue that was very hard to break.
Cracked-open.jpg

Outer-barrel.jpg


The crystal assembly looks a lot like a DPSS green. A little pac-man style brass holder with a lens glued directly on top.

Lots-of-glue.jpg


Unfortunately due to the glue holding the crystal in place I can't tell if it's a single piece or multiple.

Crystal-removed.jpg

Pump-lens.jpg


Using snap ring pliers in the two holes in the base I attempted to unscrew it, but I couldn't get it to budge. So I chucked the whole thing in a vise and started filing away at the side until a hole was uncovered.

Side-hole.jpg


Using a small screwdriver I was able to the pry the base out to reveal the C-mount diode with FAC. It was a very tight interfereence fit and took a lot of force to pry it out. Despite my best efforts to be gentle when removing it I somehow still managed to damage the laser diode and tear the bond wires going to the die so it no longer powers on.

Pump-diode.jpg


The C-mount is mounted right out to the edge of the base so it makes sense why these modules couldn't be made smaller with these pump diodes. I would love to get a replacement pump diode in 5.6mm and rebuild the module into a an old DPSS green module for a 12mm 573nm.
 





CurtisOliver

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What we know is that they are SFD (Self Frequency Doubling) DPSS's. The laser crystal pumped is able to output half the wavelength without a further SHG crystal. The actual crystal is still a mystery. But we know these are 895nm pumped instead of the 976nm the Lasence modules used. This lends itself well for Yb doped SFD crystals.
 
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Wow, I wouldn't have called it being such a short wavelength considering 532 is doubled from 1064. Still got more to learn.
 

CurtisOliver

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Wow, I wouldn't have called it being such a short wavelength considering 532 is doubled from 1064. Still got more to learn.
That’s the pump. The 532’s have a 808nm pump, a lasing crystal (Nd:YVO4) that generates 1064nm and then a doubling crystal that generates 532nm. One diode, two crystals. This has a 895nm pump, and one crystal that can both generate 1146nm and output 573nm without the need for another crystal. Hence why they are called ‘Self Frequency Doubling’.
 
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@Gryphon Nice tear-down. I appreciate the sacrifice.
For future reference, you can split the press-fit parts in two places on opposite ends with a fine saw (like a fret saw).
Then, using a flat screwdriver or other prying tool, you can insert the tip into the saw cuts and twist to push the halves apart. This should reduce the friction enough to separate the parts.

I've done some quick experiments with my Lasence module and wasn't able to get the crystals to lase with a 975 nm pump crudely directed through the pump collimator optics of the module. I haven't removed the crystals from the heatsink, but eventually will try directly pumping the crystals without any collimating optics, just to see if I can get some yellow light out.
 

kecked

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Drop it in acetone and let the solvent dissolve the glue. Toss the diode. Clean the crystal start over with fresh diode
 

WizardG

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I was under the impression the crystals in the Lasence yellows were hygroscopic and would be ruined by exposure to ambient air.
 
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I was under the impression the crystals in the Lasence yellows were hygroscopic and would be ruined by exposure to ambient air.
This has been reported by some members here, and there are published research articles that mention a crystal that lases at 573 nm with a 976 nm pump being hygroscopic. It's been a while since I dug up those papers.

I haven't seen the evidence that this is true for the crystals in the modules we've obtained, other than the anecdotes.
Based on the construction of these modules, it seems that either the crystals are not hygroscopic or the manufacturer thinks the sealing of the module is "good enough" for a commercial product.
 

CurtisOliver

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These crystals are being pumped differently to the Lasence modules. Also I asked whether these suffered from degradation and there’s been none reported yet. Either because they are sealed or it could be a different crystal entirely.
 

kecked

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If I had the time I’d try cooling one and driving it with a higher power pump to see what it can do. Bet you can get at least 100mw out of it which in yellow is a lot of visibility. My 10mw unit is very bright to the eye. So figure that would just a bout triple brightness is each power double double brightness. 10/20/40/80
 




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