Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Imperfections on Diode Window

Wolfman29

Wolfman29

0
Joined
Jan 14, 2011
Messages
3,816
Points
63
Hey all.

So I recently took the lens off of my 445 build, and, to my dismay, I discovered that the window of the diode itself is a bit "dirty."

There are three splotches, one on the mid-left, the other two on the far right-top of the "dot" profile. They are starting to "fill in" I guess with light (as in they are breaking up?), so I am not sure what's going on.

I am sure these reduce power on my diode, but it happens and that's not what I am worried about. Will these imperfections drastically reduce the lifespan of my diode? I hope not!

Thanks.
 





It depends a bit. If they reflect a significant amount of light back into the laser diode, they could expedite catastrophic optical failure. Otherwise they'll just be in the way blocking light and mucking up your beam pattern.

I'd consider decanning the diode to get rid of the tainted output window entirely.
 
Befor decanning I would try cleaning the window with pure acetone and if that dosn't work then decan it but only if you think it's so bad that it's truly is reducing your output.
If you decan it then it's going to die sooner than normal as oxygen reaching the die will degradate it faster than no O2 reaching it. this has been proven !
 
I recently cleaned the diode window on my 445, perfectly clear now. I used a q-tip dipped in a little bit of alcohol free lens cleaner on the diode window, then wrapped a microfiber cloth around another q-tip and put it in the front and lightly turned it. I kept doing 1 quick circular wipe, 1 second turn on output check, repeat until there weren't any artifacts. I also used a single 18650 batt instead of the 2 cr123a since all I was doing was checking for artifacts, not trying to burn.

And by "1 quick circular wipe", think a very light motion of turning a screw.
 
Last edited:
Let me take a picture of the lensless beam profile... then you guys tell me what you think =p

P5150060.jpg


There we go.

What do you guys think? I think those may have already actually burned through, but I can't be certain... further, I don't want to decan it unless that will *increase* the life of the diode (i.e. it's so damaged it needs it or it will die soon).

I tried cleaning it using isopropyl alcohol (70%) and a Q-tip but that didn't seem to work very well....
 
Yeah, I didn't think it was too terrible. Those spots don't even get through the lens (I rotate the lens and no artifacts stay still).

And so I should just get some pure acetone, put it on a Q-tip, and spiral it? Will have to go to the drug store tomorrow....
 
Yes. Lay the wet Q-tip on the window and spin it while you're pulling up. Do the lens too. Then repeat with a dry Q-tip.

If you push too hard you can knock the window in the can, so just take your time, and you should be good.
 
Alright, will do. But it won't come off if it's burned on at this point, would it? I have no idea how old these marks are, but they are probably about 3-5 days old, and I use this laser quite often (probably 30-60 minutes of on time a day).
 
Its worth a try, and has worked for most people. Even if it doesn't work you're fine. You'll only see those if you defocus the laser anyway.
 
Yeah. Not worried about the looks, really just about the lifetime of the laser. Anyway, +1 for all the help.
 
Those spots don't look that bad.. if they don't come off with some alcohol or acetone, i'd leave it as it is.

Flaminpyro said:
If you decan it then it's going to die sooner than normal as oxygen reaching the die will degradate it faster than no O2 reaching it. this has been proven !
Click to expand...

Could you provide a source for that info?

Perhaps the 445s are different from the 660s, but afaik the latter are commercially used in dvd writers and such, and come into contact with outside air all the time (through the drives slot or door).
 
Wolfman, I had a spot burn on the window when I was trying to clean it, just took a little longer wiping it. It DID come off.
 
You must log in or register to reply here.


Back
Top