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G-ball removal testing

kecked

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I have access to dry inert boxes at work. I was thinking to decan some ball diodes in various gas and see what happens. I’m thinking nitrogen’s d another in argon. Nitrogen is not inert.

What diodes do you want to see and I don’t have a power meter so what do you suggest? I was thinking to run them at recommended current 24/7 and measure the output once a day. If found stable once a week.

One decanned/one not decanned.

To this was thinking to add a decanned in air. This would give us the real info we need.

If this data exist let me know to save me a lot of time.

I would also like to try various methods to reseal decanned diodes.

Thoughts? What diodes?
 
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RedCowboy

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Re: B-ball removal testing

We call them G ball lenses...." G "

If you are going to do this you need to do a control group and a test group repaired and a test group exposed, so something like 5 diodes in factory condition, 5 diodes de-canned and 5 diodes de canned and re filled with inert gas, and you will need a LPM to test the results over time.

So you also need 15 modules and a power supply although giving each diode a driver would prevent problems, and you will need to sit and cycle a lot of lasers each day.
 
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paul1598419

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Re: B-ball removal testing

Actually they are ball lenses. The G stands for glass and is a carry over from the days when aspheric lenses were called G1 and G2. It seems the blue diodes are the ones that suffer from carbon deposition and lose power when decanned. I can't say for certain about the green diodes.
 

RedCowboy

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Re: B-ball removal testing

Well there not B ball lenses, that sounds like eyeglass optics for basketball players.
 

kecked

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Re: B-ball removal testing

Sloppy fingers.....

What about going to carbon dioxide atmosphere. Wonder where the carbon comes from. Cuz if it’s not oxygen, we can mix up a dry air by running it through copper in dry ice. To pull the CO2 out. The diffusion would be very slow to come back into the diodechamber with the optic as there is no difference in gradient to drive it other than diffusion.

Thinking about this I have a really simple solution. Decan and mount it in the argon Drop a little box on it with ar window. Seal it up anyway you want and you are done. You can open the box at anytime to focus and then just flush the box argon again. That is supper easy. If it is CO2 that is the problem you can also buy a media for surgery that scavenges CO2. Now it’s a fish tank air pump, a little gas filter and a bag. You load the stuff in the bag, flush the bag with cleaned air, mount, add optic, remove from bag. I’d add leads before the decan. Now that is a better idea as anyone can do this at home.
 
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RedCowboy

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Re: B-ball removal testing

Just don't do a test on 1 or 2 diodes, that's not a good study and can easily yield flawed data.
 

paul1598419

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Re: B-ball removal testing

Would be an interesting experiment if the diode count were high enough. There is no data on recanning decanned diodes that are over driven for longevity. I could get interested in decanned diodes if this were proven to improve longevity significantly.
 

Benm

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Re: B-ball removal testing

I doubt dry air would be a problem for the diodes really - there is oxygen in it, but the materials these lasers are built from are not sensitive to oxidation under their normal operating conditions.

The main risk in decanning a diode (apart from mechanical damage) would be the risk of dust contamination: Not just dust that you can see, but also very fine dust/soon with particle size of down to a few micrometers.

Such stuff is fairly common in the air, especially in urban and industrial areas as it's a normal part of exhaust. I can imagine how it would build up on the output facet of a die over time.

If you somehow manage to recreate a hermetic seal with a lens etc that'd mitigate the problem completely, and i doubt it would make -any- difference if you filled it with normal air, nitrogen or argon.

Sample sizes of 1 aren't really useful though, but you don't need expensive diodes either. Trying this with say 30 really cheap diodes would yield more information compared to using 3 expensive ones.

It would also greatly help to have a good microscope so you can inspect -what- went wrong if any of them fail: just a cracked facet, or buildup of foreign material, or even blown out bond wires.
 
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kecked

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Re: B-ball removal testing

I was hoping someone might suggest a diode series to test. I also agree that microdust is a killer. That’s easy to handle via hepa and maybe ionic attraction while decanting. The boxes are for chemistry and are only as clean as the gas we order. Help me put together testing that makes sense and I’ll get it done.
 

RedCowboy

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Re: B-ball removal testing

Something affordable yet powerful, such as nubm06 or nubm08
 

lasersbee

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Re: B-ball removal testing

Has anyone tested what actual gas/gasses
are in an original G-Ball lensed LD...:thinking:

Jerry
 

Benm

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Re: B-ball removal testing

Given the small volume i think that might be hard to actually test.

Maybe it's somehow possible to puncture the encosure with a syringe and insert the gas into a sensitive GC, but you'd still have to do all that in a known atmosphere that's not likely to match what could be in the diode.

It could be done under SF6 and in argon, presuming they don't contain a mixture of those gasses. This could be a faulty assumption as both are used in sealing eletronics, though SF6 is typically only used in high voltage applications.
 




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