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Green lasers beam combining

ufo

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Feb 10, 2010
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Hi,

Yesterday I found 7 pcs 100mW green laser modules with TEC without purpose.
I wondered what to do with them. Yes, totaly 700mW in one beam is only what I want :) I studied on this forum about laser beam combining with same wavelenght for some hours and choose knife edge solution with two convex lens. Here is my result (first time only with 2 modules):
main-nigt.jpg


Here is knife edge photo:
knifeEdge.jpg


Here is photo knife edge and first lens.
biggerLens.jpg


Unfortunately, I found two problems. I need help, please.
Problem 1) Combinend beams have bigger beam diametter. I maked small experiment. Look at this picture with two laser dots:
BiggerDot.jpg


Left smaller dot is beam directly from first module. Second laser beam through first convex lens is much bigger. Is it a problem with the choice of the bad lens?

Problem 2) This problem is with my laser number 2. Laser 1 working without problmes - small circle dot, but second laser have not circle dot. Looks as elipse. Please see photo:
BadLaser.jpg


I found when I am turning current to this module, elipse change shape. Is it bad centre aligning crystal in module?

Thanks for your help :)
Milan
 



ARG

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Feb 27, 2011
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Try having the beams initially parallel to each other.

I posted a thread about beam combing somewhere, refer to the diagrams there. I would link it but I'm on mobile.
 

ufo

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get a polarizing beamsplitter cube. then you can overlap them fully. :)

Thanks for reply. Problem is not with overlaping. I can overlap beams very good. Problem is that final point is much bigger. I think I must put one small lens into output to fina focusing.
 

ultimatekaiser

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The two lasers do not have the same divergence. The and the other one is mode hopping. Which is why pay it is more elliptical. It's alignment or thermals (or both) are not managed properly. It's not quite TEM01, but it's darn close. It changes shape when you up the current because it can't handle the heat, making the pump diameter grow so you get additional reflections.
 
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Alaskan

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Love the photo's, I'm interested in doing the same.
 

Pman

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"Yesterday I found 7 pcs 100mW green laser modules with TEC without purpose."
I "find" stuff like that all the time. Just throw it in the basement with all my pirate treasure;)
 

iroquois

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Please tell me if I'm getting all this: can't you replace a knife edge array with just the lasers in parallel and a way larger lenses to narrow them into a single beam?
 
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Alaskan

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I am learning on this myself, but from what I can tell, the knife edge allows the beams to be placed very closely together, without the array of mirrors, they can't be placed as closely together. I have some knife edge arrays out of a projector with lenses built into each of them, I believe the lens helps bring the individual streams of light even closer together so they appear to be one, but I haven't tried building with them yet.

Anyone?
 
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starlight

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I am learning on this myself, but from what I can tell, the knife edge allows the beams to be placed very closely together, without the array of mirrors, they can't be placed as closely together. I have some knife edge arrays out of a projector with lenses built into each of them, I believe the lens helps bring the individual streams of light even closer together so they appear to be one, but I haven't tried building with them yet.

Anyone?
I was gonna try but never could never find a knife edge array. A member here was gonna send me one but never did or forgot. Anyone else know where to find knife edge array's?
 

sellersmd

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Apr 10, 2014
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I was gonna try but never could never find a knife edge array. A member here was gonna send me one but never did or forgot. Anyone else know where to find knife edge array's?

DTR has some listed for sale in his shop.
 

starlight

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I stared at his site and "never" looked to the left. I only was looking at the pictures as links to each category . Thanks
 




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