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About Gball diode

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Hello, today i have some questions about gball diode (nubm0x,nugmox )
All gball diode is cheaper than other diode (same power) -good to buy but it is fix beam and to solve we have to remove the gball lens
I think the removal techniques are perfect and this topic I only consider about oxidation when exposed to air.Does that reduce the life of the diode ? Anyone who has tested, can tell me the resultl
Yeah, because i bought a bank nubm08 yesterday
and want use them to built laserpointer, Thank all.
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Alaskan

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The NUBM07E 5 watt capable output 465 nm laser diodes all appear to have very short lives when de-canned, makes me want to stay away from blue diodes which have had the can removed. As you well know, there are lower power red wavelength diodes which do not use cans, so the problem may be material related, or perhaps power level, when exposed to normal air.
 

paul1598419

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I think it is more likely a power problem with oxidation of the die. So, decanning any ball lens diodes could shorten the life of the diode if they are in the multiple watts.
 

Alaskan

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I believe so too, but why are low power red wavelength diodes made without a can and don't have the problem?
 

RedCowboy

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The area of the diodes P/N junction where the beam exits the front OC mirror is very tiny, the energy density must be the issue that causes damage to the OC mirror due to air/moisture/oxygen.......

Here you can see how tiny the P/N junction exit is through the front mirror on the right, the box on the left is the anti static device.



Apparently some exits the rear mirror as well, you can see the black spots are where my microscope CCD is overdriven.




I have had several de-canned 07 diodes die in just weeks, I had a 08 de-canned that lasted about 1 month of daily use until about half bright at 4.0 amps and I have had 06 diodes wear out but for some reason the 06 seems to be holding up better de-canned, maybe because I have this de-canned 06 primary lens locked in at a set focus and do all my focusing with a beam expander, it has held up pretty well so far.

The 06 and 07 both have stage 2 divergence like the 7A75, about 2X the line width of a m-140/7875 and the 08/44 have 3X the divergence/line width of the m-140/7875 so that does not seem to be an issue, however the 07 diodes do wear out the fastest it seems.

The de-canned 06 is in the unit on top in this pic and is sealed in pretty well, only the beam expander gets adjusted so it may have consumed what ever was in the air trapped between the primary G7 ( which has tighter threads than 3 element lens barrels ) and the diode that's pressed into a copper 12mm module. There's also a little loc-tite under the beam expander that threads into this heat sink that Lifetime17 machined for me.

 
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Thanks everyone - the removal of the Gball really dangerous-maybe all Gball diode is high power-The case of the red diode is an exception as it has low power (150mw-1w)-So we need an expander instead of remove gball - anyway the Gball diode is still very nice - i like nubm08 and nubm07e
 
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You can refocus the output from a gball diode with a set of bi-convex or plano-convex lenses by adjusting the distance between the lenses like |DIODE|----()<----->()---> the <------> is the distance that you adjust until you get a tight beam. It's basically the same setup you would do for a spatial filter but without the pinhole between the two lenses for the filter.
 

Alaskan

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I was thinking better to leave the Gball lens in place, don't remove it, just add a negative focal length lens in front to take it out of focus, then add a regulator collimation lens in front, but man, adding losses. However, if AR coated and a quality coat, shouldn't be unacceptable, but the price and complexity goes up.

e: Some of those Gballs are perfectly collimated, no need to do that, some are a little bit out, but I do like to have a focus on my pointers, sometimes I use them to understand optics better at different wavelengths and need an out of focus source, actually, I do that a lot and instead of having a dedicated setup for a raw output, just use a pointer, so an adjustable focus, or the ability to remove the lens is important to me.
 
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RedCowboy

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About 1 out of 4 NUBM06 diodes ( I have bought about a dozen ) have a pretty decent focus and can be made to burn at 20 feet with a Sanwu 3XBE, the others just diverge too fast.

Point is that not all GBall lenses focus the same, one block may have a pretty good RX and another block may diverge really fast, I assume that the OEM orders them with the lens RX to suite their need.

I have attempted many times to remove a lens from the can but they always break, almost as if they are under tension, they are roll sealed in it seems, there's no threaded lock ring, they look to have a machine rolled lip in the can.

 
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Alaskan

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Only reason I knew that about these lenses, some being different, some right on, was due to your findings. I don't have any of those diodes yet, maybe someday, but only if I decide on a way to refill the diode mount with inner gas somehow, without too much complexity, but we've talked about that before and came up with a way, if using Teflon tape on the lens thread and the back end of the diode pressed in is tight enough to leakage.
 

RedCowboy

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In the case of this latest 06 just sealing the module/primary lens and doing my focusing with the BE has if nothing else seemingly slowed down the degradation, but I don't have a true test/data to prove that.
 

Alaskan

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Maybe it's a combination of moisture as well as power and exposure to oxygen are all possible factors, but sealing it after being opened allows oxygen in, however maybe less moisture, depending upon the relative humidity when you did it, hmmmm....
 
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i have read somewhere that a decaned nubm44 is not degrading as the other high powered gball diodes,im sure that all the series of blue gballs degrade if the can removed but i don't know what is happens on the green diodes.anyone have any info?


The NUBM07E 5 watt capable output 465 nm laser
diodes all appear to have very short lives when de-canned, makes me want to stay away from blue diodes which have had the can removed. As you well know, there are lower power red wavelength diodes which do not use cans, so the problem may be material related, or perhaps power level, when exposed to normal air.
did anyone asked for a nubm07 with a normal can? :D

https://www.ebay.com/itm/Brand-New-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649
 

RedCowboy

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I would not be surprised if the de-canned diodes when run until warm are actually hot at the diode/lens and the air trapped would expand and some would escape past the lens barrel threads, then when it cools the vacuum created would draw some new air in, this could present a moisture problem from the normal humidity in the air.

It's just a theory, would be interesting to do a study, if using Teflon tape and setting to an infinity focus vs. turning the focus ring regularly and see if there was a difference in lifespan.
 
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I would not be surprised if the de-canned diodes when run until warm are actually hot at the diode/lens and the air trapped would expand and some would escape past the lens barrel threads, then when it cools the vacuum created would draw some new air in, this could present a moisture problem from the normal humidity in the air.

It's just a theory, would be interesting to do a study, if using Teflon tape and setting to an infinity focus vs. turning the focus ring regularly and see if there was a difference in lifespan.
i have to agree that most likely the air expands inside the housing between diode and lens as those diodes tend to work hot,imagine the temperature that the emmiter actually has while running, this wwould expand and after that shrink air back in the housing area bringing dust and humidity inside
 




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