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ArcticMyst Security by Avery

445 laser diode died sad day

  • Thread starter Deleted member 16589
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Deleted member 16589

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Ok so yesterday I finished my laser I was building and it died here is what I did

After I finished the laser I set the driver to 250mA and then connected the laser diode and turned it on the laser and it lased at like less than a mW so I slowly turned up the diode control until the laser lit an when it did it was super bright. Nowhere near one watt much lower.
so after that I turned it off and about ten minutes later I turned it on and lit a match with it at the focal point lit a match with it to test the power.
later I turned it on again aimed it against the wall and slowly turned it to focus it into a beam but as I was turning the lens a hug black spot formed in the middle of the dot on the wall.
After looking at the diode it looked like this http://82.69.127.162/images/lazor_images/2165_Laser_Diode_Window_PHR.jpg
only on mine the window was also cracked up.
I was told to fix it I would have to decan it but when I tilted it the hole fricking window fell into the diode and then fell out when I tilted down.
now the diode emits very little blue light and even a small line of green ??
I was told static killed it but I do not believe that for one second.

after talking to some people I have found out that the AR coating is missing on the bottom concave lens that faces the diode.
so for now I guess I am screwed.

the driver I used was this
http://www.ultralasers.com/proinfo.php?productid=62&cat=27&page=1&featured
and I used an N-Type ham radio dummy load for heat-sinking

And before you post it yes i put this on PL too.
 
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your links dont work

but yeah im having trouble powering my 445nm atm =[

but anyways what do you mean about the window fell in and whole thing fell out
 
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i think he means the window on the diode fell into the diode (if its even possible) and then ended up falling out of the diode.

im still learning my way through lasers atm and learning quicky, i need ot buy a diode soon to find out the structure fully but anyway hope you can find out how to prevent it from happening again, sorry i couldnt be of much help.
 
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Deleted member 16589

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i think he means the window on the diode fell into the diode (if its even possible) and then ended up falling out of the diode.
YES that is what I meant

As far as output goes ill measure the current from the driver when I get a chance.
My old 405nm PHR build would light matches much easier.
 
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after talking to some people I have found out that the AR coating is missing on the bottom concave lens that faces the diode.
so for now I guess I am screwed.

What does this have to do with your diode's death?

To me it sounds more like the death was caused by contaminants burned onto the diode window or by the window breaking and damaging the emitter.
 
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Deleted member 16589

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What does this have to do with your diode's death?

To me it sounds more like the death was caused by contaminants burned onto the diode window or by the window breaking and damaging the emitter.

If that is true why did it happen when i turned the lens and not the very first time I ran the laser

The AR coating was missing on the concave lense facing the diode lens
 

DTR

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The picture does look like something got on the diode window and baked it. I would guess the glass got so hot the glue(green stuff) that holds the window on inside the can melted and your window came loose. Once you window was loose it could have easily come in contact with the internals and damaging them.

When you turned the lens something that was in the threads could have dropped onto the diode window. Did you use Teflon tape or anything to tighten the threading on the lens?
 
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Deleted member 16589

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No I had just finished building it I was testing focus and power.
Also that picture is not mine it just looks similar to what happened to mine
 
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What does this have to do with your diode's death?

To me it sounds more like the death was caused by contaminants burned onto the diode window or by the window breaking and damaging the emitter.

I had a friend who broke like 3 diodes the same way - the lens on it would crack and fall into the diode it self - not the focusing lens but the actual lens on the diode or whatever that glass window is the OP was talking about

after the 3rd one he asked a friend to examine the broken pieces to see whats what using a really powerful microscope they had access at college - well after some readings it was determined that there was "skin particles" within the broken pieces and some other stuff that was determined to be nothing more then oil from his finger

I guess he had touched the lens with his finger to clean it - yea stupid I know - he said that he had a row of 6 diodes and some dust had gotten onto them so he brushed it off with his finger lightly he said - well it must have been oils and such that when heated up by the laser it cracked the lens just how a halogen bulb or other HPS or MH bulb


he just cleaned the other 3 he had using "agent blue" and 99.9% ethanol alcohol - the agent blue was probably not needed and I would have never used it but the 99.9% ethanol alcohol worked fine





in case you dont know "agent blue" is a really high end optical glass cleaner that NASA and others use for cleaning sensitive things made out of optical grade glass/plastic or better - although it must be followed up with 99.9% or better pure ethanol alcohol - I think it removes any coating there is applied but the 3 diodes work fine - it has an anti static additive that allows it to be used for cleaning anything other then CCD's and other imaging receivers - that must be cleaned with ultrasonic sound waves
 

HIMNL9

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"the bottom concave lens that faces the diode"

???????

Sorry, what do you mean ? ..... as far as i know, there are no laser lenses that is concave at the laser side ..... in a triplet, there is a concave lens, but is between two convex ones, all the other lenses are convex, usually biconvex, almost symmetrical the ones in the triplets, and much more convex at LD sive the single elements ones .....

The only concave element that face a laser that i can remember, is the expander in front of a green crystal :confused:
 
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Deleted member 16589

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On the aixiz lens the lens surface surface closest to the diode is concave that surface was missing the coating.
 

HIMNL9

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Uhm, sorry, but no ..... i have some Aixiz lenses, and none of them is concave on LD side ..... few convex, yes, almost flat ..... not concave.
 
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afaik the coating seems to be much easier to see on the front element thna the back- this somewhat gives the apperarence that the back element is uncoated.

over a hundred lenses have gone thru me and i dont think any were coated on one side only- when you get your free replacement lens from AixiZ take a close look.

plz let me know if I can be of assistance.
 
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Deleted member 16589

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afaik the coating seems to be much easier to see on the front element thna the back- this somewhat gives the apperarence that the back element is uncoated.

over a hundred lenses have gone thru me and i dont think any were coated on one side only- when you get your free replacement lens from AixiZ take a close look.


WOW just opened my new lens and its coating is a nice orange color
and the concave surface is clearly coated properly.

and my old lens is clearly missing the coating on the concave surface
I will be sending the defected lens back to you hak this week.
 
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i just got done making mine they work great i you want ill sell u the red one
 

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Deleted member 16589

Guest
"the bottom concave lens that faces the diode"

???????

Sorry, what do you mean ? ..... as far as i know, there are no laser lenses that is concave at the laser side ..... in a triplet, there is a concave lens, but is between two convex ones, all the other lenses are convex, usually biconvex, almost symmetrical the ones in the triplets, and much more convex at LD sive the single elements ones .....

The only concave element that face a laser that i can remember, is the expander in front of a green crystal :confused:

this is the messed up surface I was Referring to
http://weasel.brazi.net/webstuff/lpf/IMG_0046.JPG
please note this is not my picture
 
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