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Im getting 1w on an NDG700 with a 2 element I'm sure you will be over,
The loss isn't that much!
The loss isn't that much!
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Which Green Diode ?
- Thread starter Mosc007
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Doing some searching on the G2 lens. It does appear you are correct about the AR coating is only for Blue Diodes.
520 must be reflecting a small amount back into the diode.
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Thanks, Mosc007. Every so often I've been known to get something right. 
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Ha, Paul you get many things right.
The only thing is I know that I have seen this with an M140 which the AR coating is supposedly for. Either the AR coating is solely for 405, or it isn't particularly doing a great job.
The only thing is I know that I have seen this with an M140 which the AR coating is supposedly for. Either the AR coating is solely for 405, or it isn't particularly doing a great job.
Ha, Paul you get many things right.
The only thing is I know that I have seen this with an M140 which the AR coating is supposedly for. Either the AR coating is solely for 405, or it isn't particularly doing a great job.
The exact spec is very hard to find. Some sellers say 405nm. Some say 405nm, 450nm, Some say 405nm, 450nm, 515nm.
Maybe it is only 405 nm.
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Well, the only thing I can think of is that the G2 was originally intended for the 405.
This is DTR's listing for the G2, and it looks to be primarily for 405. But it also says 400-600nm AR coating. From that I'm guessing you can expect a curve with the peak above 405nm. :thinking:
It would explain why the box reflection is brighter on the 520. As the efficiency of the AR coating starts dropping off leading to some reflection.
405-G-2 Glass Lens for Aixiz Laser Module 405nm 445nm | eBay
This is DTR's listing for the G2, and it looks to be primarily for 405. But it also says 400-600nm AR coating. From that I'm guessing you can expect a curve with the peak above 405nm. :thinking:
It would explain why the box reflection is brighter on the 520. As the efficiency of the AR coating starts dropping off leading to some reflection.
405-G-2 Glass Lens for Aixiz Laser Module 405nm 445nm | eBay
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I personally have many single element aspherical lenses from many different suppliers just for this purpose. I have found that one will work better in one application while another will work better in a different one. It's a matter of trial and error.
The 2 element 520 lens arrived from DTR. This lense also has a minor problem with the NDG7475.
Their is spatial light coming from the lense. Quite a wide angle. Not very bright but a lot of it.
Out of all 3 lenses tried the 3 element glass has the cleanest output. Nice beam and collimated well. Just the lowest output though. I will test the output soon.
Looks like i will use the 3 element glass with this diode.
Their is spatial light coming from the lense. Quite a wide angle. Not very bright but a lot of it.
Out of all 3 lenses tried the 3 element glass has the cleanest output. Nice beam and collimated well. Just the lowest output though. I will test the output soon.
Looks like i will use the 3 element glass with this diode.
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