I.R. Light strange READ THIS PLEASE

deezdrama05

Enlightened
Joined
Feb 21, 2005
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251
Location
ill usa
I have my leadlight tooken apart and wile trying to align the disc with the mca's in it to get a green beam it is very hard to find a good spot so I got out my digital camera to take a pick of the IR light, and what I found is very strange - take a look at this pick. What would make the IR LIGHT shaped this way with those dark blotches? Is my diode bad? lens backwords? This is the IR from the diode going through the first 2 lenses with no mca colimating lens and ir filter on a white piece of paper at about 6 inches away. Any ideas??? /ubbthreads/images/graemlins/confused.gif
http://home.insightbb.com/~deezdrama05/IMAG0329.JPG
 
i would say dust on your lenses or just in the air, also, IR behaves diffrently to visible wave lengths, doesn't focus the same, refracts/reflects diffrently off diffrent objects.
 
Ok cool - also just to make sure on the 105 the first 2 lenses before the mca - the first one the flat side faces diode, and the next lens the round side faces first lens. Is this correct?
 
This is Not because of dust of the lens. Its because of the laser diode. If u can move the lens, u can see the pattern will not move with the lens. I've aimed a CD IR laser diode directly to my eye and saw the same pattern wich will rotate if I rotate the LD(the 780nm IR is visible and <1mW power is hamless without lens and viewed in near distance because it will not focus).
 
Yeah I shot the bare diode at a piece of paper and took another pic and it looked the same. Should the diodes ir pattern be round and uniform or is this normal??
 
Mine looked like this:

ir_low1.jpg


Looks quite a 'clean' beam compared to yours. /ubbthreads/images/graemlins/thinking.gif
 
It looks like in the pick that alot of ir was being produced, mine i dont think is making that much so maybee my diode is bad
 
It was a 350mw diode though... /ubbthreads/images/graemlins/icon3.gif

You probably just have a standard 200mw.
 
I have a red laser pointer that does the exact same thing when I adjust focus to wide-spread. At first I thought it was dirty lenses but it was coming from the diode itself.

Sorry, I really don't think there is much you can do about the strange dark circles.
 
If you are just looking at the diode-
Dirt particles on the diode window or facet causes this..
Or a damaged diode can do this too..
I have also found foreign dust like material trapped loose inside the diodes as well...
Dirty optics also,. I have quit a collection of optics here and keeping dust off of them is a real chore.

When I do beam expandings they really show up..I live in a dusty environment.
So lately ,I use plastic containers to keep them in around my test area.
 
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