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FS: 405-G-1 Glass Lens Mod - 31% Increase vs AixiZ!

Papango

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I tried to remove the stock lens and instead put a photographic lens directly in front of the raw beam...

It burns like hell @5m and produces a very tiny spot (0.5x0.5mm) ...
Is that how a beam expander works ?
 



Alaskan

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Seems like you merely focused the output of the laser diode with a bigger lens, didn't have it focused to what is considered infinity. At infinity, if you held a PCX or plano-convex lens out in front of the raw output of a laser diode the spot would be a larger diameter and be more difficult to burn anything, if at all. If your stock lens wasn't flat on one side, you were just focusing it with a bigger lens, that's all.

You can make a beam expander with a convex lens(es), there are some diagrams showing how to make them at this link as a downloadable PDF doc:

http://assets.newport.com/webDocuments-EN/images/How_to_Build_a_Beam_Expander_5.pdf
 
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Papango

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Yes it's just focused At a certain distance .
I need to adjust the focus each time I move far away by moving the lens toward the raw Beam.

I tried at 10m and it still burns but the dot is a little bit bigger (2x2mm).

Then I tried outside from my roof , I focused it the more far away I could see with a binoculars , it easily goes far beyond a miles but I doubt it will burn anything .

You are right , at the output of the lens the beam is about 2cm wide which is the lens size.

Just saw the beam expander schematic , it's not really like that, the beam is only bigger near the lens but goes narrower with distance until â Small spot then diverges again . I will try with a 50mm lens it should be more precise and infinity focus should be better ?
 
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