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Twin Blue Beams !

CurtisOliver

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Yes, it is in fact the lens responsible for the apparent axis switch. So the fast axis is in fact what you should expect; yet when collimated, the specs alter to the point of being the opposite way round. Have I understood? :p
 

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Yes, it is in fact the lens responsible for the apparent axis switch. So the fast axis is in fact what you should expect; yet when collimated, the specs alter to the point of being the opposite way round. Have I understood? :p
I think I might have added some more text to my post after you posted so you should go back and check if there is something I added that you maybe missed ?
 
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CurtisOliver

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I measured mine with a G2 lens, so the beam specs will differ slightly. Can you do a test with far/mid and close field with a collimated beam?
 
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I measured mine with a G2 lens, so the beam specs will differ slightly.
From what I can work out.
I think the problem is coming down to how extreme the fast axis originally is. The lens is over compensating the slow axis giving a negative divergence due to the large fast axis.
Yes I believe it's the wider angle the beam enters the lens with one axis's angle being much greater than the other ?

Lets say one is 30 or even 40 degrees wide and the other is like 15 degrees wide ?
 
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BobMc

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One of these beams is 2.2 watts and one is 7+ watts, Can you tell which is which ? lol


Oooooouw, pretty blue photons ! You can never have enough. Nice, build turned out real good, enjoy :)

It's the one on the right, the 7 watt. (now if you could put a potentiometer on that guy.) :thinking:
 
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CurtisOliver

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I just edited my post sorry.
I'm trying to determine what it is that is causing the lens to reverse the beams divergence. The only thing I can think of it is that the lens is too powerful of the slow axis. The G2 lens is capable of slowing the fast axis down to around 1mRad, yet the slow axis has been increased to around 11mRad. This would mean that the lens has over-focused the slow axis to the point of re-expanding. I do believe that this laser would benefit from simply having two cylindrical lenses instead of a 3-element or G2 etc.
 
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The problem as I see it is you can only bring both axis's to a single point at a well defined focal length when using a symmetrically ground lens that is rotated to focus, I believe you could maybe bring both axis's to a point at different focal lengths IF a lens could be made with a non-symmetrically ground profile BUT you would have to focus the lens for different focal lengths by moving it closer or farther away from the diode without rotating it......
 
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CurtisOliver

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This is why you would use plano-cylindrical lenses as it then only focuses one axis at a time.
 
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This is why you would use plano-cylindrical lenses as it then only focuses one axis at a time.
Exactly !

But I can invision a system that could do the same thing as all those lens's but using only one focusing lens BUT it would cost a small fortune to manufacture such a system.......
 
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CurtisOliver

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I sure would cost a fortune to manufacture. It would be a slightly cross shaped lens. It would be interesting, but I can't see manufactures justifying the cost compared to combining two standard lenses. If they designed a lens barrel that had two PCL's designed for that specific diode, I sure would buy it.
 
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I sure would cost a fortune to manufacture. It would be a slightly cross shaped lens. It would be interesting, but I can't see manufactures justifying the cost compared to combining two standard lenses. If they designed a lens barrel that had two PCL's designed for that specific diode, I sure would buy it.
Or you could buy a diode that doesn't diverge like the 44 and much cheaper than that system would cost to manufacture I would imagine ! lol
 
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CurtisOliver

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I like prefer the term, lasers can burn a hole in your pocket. Because it true both ways. :p
I actually have two NUBM44's for that purpose Alaskan, but have never got round to it. :) Now that's a scary thought.
 
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