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ArcticMyst Security by Avery

9mm diode w/ 3 Element Lens?

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Aug 3, 2011
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Alright, got a bit of a debate for you guys, something Ive been pondering on but haven't tried yet.

The question is: Do you think it is safe to use a 3 element glass lens with the 9mm diode.

The reason I ask is because I have heard before that it isn't safe to use a 3 element on anything above 1.5W or so due to the reflections back into the diode from where the output hits the lens barrel.

I would like to put a 3 element on one of my 9mm cause I really like the beam pattern of the 3 element lenses much better, makes a much tighter beam then the G2/G9 lenses.

Let me know what all of you think.
 





Blord

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Using the 3-element glass lens with the 9mm diode is harmless. It is all glass and metal, nothing will melt.
The first glass surface of the G lens is also straight and we are using this G lens all the time at any power output. So I don't know where you heard the reflection of the glass surface will kill the diode. The glass window of the diode is also straight.

What is true is that the reflection from a mirror will kill the diode.
 
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Jun 7, 2012
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With how much closer the stock 9mm lens is to the diode I'd bet more light is reflected into the diode with that lens than a 3 element. I can second Blord though that either lens is safe.
 
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Jul 22, 2012
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Remember that the 3 element lens should have an AR (anti-reflective) coating on the lens for 445nm:whistle:
 
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Remember that the 3 element lens should have an AR (anti-reflective) coating on the lens for 445nm:whistle:

Well I was more worried about the back reflection off the nut itself, as I am aware of the AR coating:na:

Thanks for the answers everyone, gonna give it a shot, see how nasty that splash is with ~2.8W.
 
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Jul 22, 2012
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I just want to add that from all the 3 element glass lenses I have seen ,the nuts were colored black. So even if it did reflect some of the laser diode's output it will be very weak.
 
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I have a 3W build I did with a 3-element lens and a G-2 lens. I mainly use the 3-element lens and havn't had any issues at all. It just puts out a bit less power than the G-2 lens, but has a way nicer long distance beam. It doesn't seem to heat up any faster and the laser is still putting out the same power as day 1.
 




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