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



Odd beam obstruction

ElectricPlasma

Super Moderator
Staff member
Joined
Dec 11, 2015
Messages
1,637
Points
113
I haven't really looked at my 520nm build unfocused, it's either been focused to burn or focused to infinity. I took a look at the diode output w/o the lens, take a look at what I found.



I've tried to get it out with one of those compressed air can cleaners, didn't help at all. Here's what the beam looks like focused through a 3-element:



It's not easy to see a part of the beam missing, in fact I would've never noticed it if I didn't take a look at the beam's raw output, simply because of how bright this thing's beam is already at around 800mW.

It's honestly no big deal to me, I originally intended on this build (my first) to be a "wow look at that" kind of project, with no relative or practical purpose, so I don't mind if it stays as I can hardly see it at all. Also the last thing I would want to do is damage the diode further by trying to get rid of this... Any ideas of how to get rid of it safely? How to clean the raw diode? Thanks.
 



RedCowboy

Well-known member
Joined
Jul 10, 2015
Messages
9,526
Points
113
Looks like junk on your window, if it burns hot enough it could crack the window.

It could be on your screw in lens, when you focus does it move, spin with the lens turning?
If so it's on your focus lens, no problem, but on your window it will sit still and seem to get smaller as you focus.
That's only a 1 watt Right?
It may not pop, but 3w and up often will.
 
Last edited:

ElectricPlasma

Super Moderator
Staff member
Joined
Dec 11, 2015
Messages
1,637
Points
113
Looks like junk on your window, if it burns hot enough it could crack the window.

It could be on your screw in lens, when you focus does it move, spin with the lens turning?
If so it's on your focus lens, no problem, but on your window it will sit still and seem to get smaller as you focus.
That's only a 1 watt Right?
It may not pop, but 3w and up often will.
~800mW of 520nm. Not even 1 watt :p

Nope. Completely on the diode window, can't even see it when it's focused
 
Last edited:

H2Oxide

Well-known member
Joined
Dec 11, 2014
Messages
1,016
Points
83
Do you have a stereo microscope you could look at the diode through? Perhaps you could clean the window with lens cloth?

Or you could just pull a USAbro and try to drill the window out.
 
Last edited:

ElectricPlasma

Super Moderator
Staff member
Joined
Dec 11, 2015
Messages
1,637
Points
113
Do you have a stereo microscope you could look at the diode through? Perhaps you could clean the window with lens cloth?

Or you could just pull a USAbro and try to drill the window out.
Wow :crackup::crackup::crackup: just read through that thread, gave me a good laugh. A Q-tip was brought up, that seemed like a good idea though. I don't have a microscope but I'll probably just end up using a lens cleaner or a q-tip.

Still can't believe he drilled a damn hole in his diode :crackup:
 

Pi R Squared

New member
Joined
May 14, 2013
Messages
3,798
Points
0
No don't try to clean it or do anything, if it's not broke don't fix it. Look at my build thread from 2 1/2 years ago, scroll down near the end of the first post and you will see I have the same thing with this 3W laser and it still works fine. I could never see anything on the diode window with a powerful magnifying glass but I don't have a microscope so I don't know if it's the window or some defect in the diode.
http://laserpointerforums.com/f65/assembled-445nm-9mm-stainless-steel-host-pic-heavy-85997.html

Alan
 

Lifetime17

Well-known member
LPF Site Supporter
Joined
Dec 15, 2014
Messages
6,149
Points
113
Hi,
If it's no big dealt you like PI said leave ti alone, but if it is Take the can off the diode that will fix your burnt window issue. but note the diode will be at risk if you get dust or dirt on it Poof!!! I have quite a few diodes without windows that i de canned and they run fine just have to be a little more care full that'll.

Rich:)
 

InfinitusEquitas

Well-known member
Joined
Mar 27, 2011
Messages
15,449
Points
113
Could be diode defect, but more likely an issue with the window or lens.

Try cleaning both with microfiber cloth, and leave it alone after that. At most you're losing a small amount of power.
 

Pman

Well-known member
Joined
Nov 28, 2012
Messages
4,445
Points
113
Agree with everyone else. Don't mess with it. I don't really like Q-tips as they could leave a hair and make things worse. It's really not a problem at this point so don't take the chance and turn it into one. IF you can't leave it alone then go the micro-fiber route like Infin mentioned. Don't do a de-canning unless you'RE really sure of yourself.
 
Last edited:

ElectricPlasma

Super Moderator
Staff member
Joined
Dec 11, 2015
Messages
1,637
Points
113
Thanks, everyone. I definitely won't decan the thing, it wouldn't be worth it for a smudge. Rather have it protected. Eventually I'll probably get a microfiber cloth and try to get at it. A shame that a compressed air can couldn't do the job. :)
 

ElectricPlasma

Super Moderator
Staff member
Joined
Dec 11, 2015
Messages
1,637
Points
113
It's a bad idea in general to use compressed air, since it's not just air that's in there.

I like these personally, for use with glasses, and lenses: http://www.amazon.com/Eco-Fused-Mic...&redirect=true&ref_=oh_aui_detailpage_o00_s00
I think as long as you have the can up right it will only decompress the bottle, and leave the mixture that creates the reaction inside, thus only putting out well... compressed air. Turning the bottle upside down is when other things start coming out of the bottle :p

I'll have to see if I have any microfiber cloths around, if not I'll probably purchase the ones you linked.
 

InfinitusEquitas

Well-known member
Joined
Mar 27, 2011
Messages
15,449
Points
113
Even if you hold the can completely upright, you still get some very small amounts of residue... and you still often drastically cool whatever it is you're cleaning.

Don't necessarily need a microfiber cloth... any soft non abrasive cloth that's basically lint free would work. I use old cotton t shirts often.
 




Top