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After focusing "Whiskers"

Berc12321

Berc12321

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Just got my 1.3 watt 445nm build together and noticed this:
GzStH.jpg


:wtf:

Its focused to the smallest spot possible, but it has these huge whiskers. This is at maybe 6ft range and the spread is of 1.5ft radius (each).

M140 diode through a 405 G-2 lens.

Ideas?
 
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Please post a picture w/o the lens as well. Just raw diode output.

Most likely a lens issue though. Did you make sure the lens is not upside down? lol
 
Looks to me like you might have the lens in backwards... I had a similar effect happen to me with a 3-element lens in backwards. It created an hourglass shape.
 
I flipped the lens around and same deal, looked exactly the same. Maybe I'm an idiot and put it in the same way but I doubt it. I have it now as the convex side of the lens is pointing towards the diode.


qunzgl.jpg

That's the unfocused beam right out of the diode.


At Infinitus, I think it was your post, but I read about someone with an hourglass beam and they flipped the lens around and it was fine. I tried after that and same same.

Tomorrow I'm heading to my physics professors to play with his bench power supply and see if he can fix my woes.
 
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Turn the lens in the laser and look if the whiskers also turn. If yes then it is a lens problem. If not then is the diode problem.

The raw output looks good. Maybe the lens has a tiny air bubble that scatters the light around.
 
They do not turn with the lens, as I turn the lens the circle tightens into a dot leaving the whiskers in place.
 
Berc12321 said:
Just got my 1.3 watt 445nm build together and noticed this:
GzStH.jpg


:wtf:

Its focused to the smallest spot possible, but it has these huge whiskers. This is at maybe 6ft range and the spread is of 1.5ft radius (each).

M140 diode through a 405 G-2 lens.

Ideas?
Click to expand...


Where did you get the lens? Looks almost like the stock kassio collimator, they produce
a big stripe on each side of the beam.

Just thought id throw that out there, in case it was purchased from an unknown..
 
JLSE said:
Where did you get the lens? Looks almost like the stock kassio collimator, they produce
a big stripe on each side of the beam.

Just thought id throw that out there, in case it was purchased from an unknown..
Click to expand...

I got it from dtr-lpf on eBay. I would assume the lpf refers to his presence on here. He also has 100% seller rating over 1100 products sold which means he's god of customer service and not cheating people.
 
Just found him. I'm forwarding the thread.

He's a damn good seller. Very helpful and lots of patience.
 
Well unless it was a mix up, I doubt you have the wrong lens.. I was thinking
you may have purchased it from an ebay seller passing off cheap lenses
but knowing the seller, that's not going to be the issue here.

Have you tried any other lenses?

The only thing I can think of is possible a crack right through the center of the
diode's window, or something in the optical path. TBH, I have never seen anything
resembling that, other than the lens I mentioned :thinking:
 
That is very strange. It would not have been backwards as I test each lens after I mount them to make sure they have a nice clean beam and they have a focus ring on them so you should not be able to mix it up. Is is possible something has gotten on the lens?

Can you take a picture of the unit with the lens unfocused a bit to see if there is any debris that has gotten on the lens and then a picture of the raw output without a lens.

If you want you can send it back to me and I will figure out what is wrong with it.:beer:
 
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Can you take a picture of what the output looks like through goggles?

Or from further away, unfocused?

Idk, to me it seems the lens is just backwards... I've seen similar output like that firsthand.

This is what I'm talking about:

5415516179_3da652165c_z.jpg
 
Try flipping the lens again,
But ur raw diode output actually looks a little strange to me
It seems to have a () shape, I would expect it to be more || shape
But it may just be the camera?
 
his raw output looks right to me, its a cross between a || and a (), I would say he got a bad lens though I am still trying to replicate his output by changing g1 lens around, but no luck yet. Did you have a custom spacer or nut holding you lens close to the window, G2 and G1 lenses sit closer to the diode than an axis lens. oops nm I see that DTR assembled the lens.
 
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