Re: FS: 405-G-1 Glass Lens Mod-28% Increase vs Aix
Hey Jay,
thanks for letting me know you shipped my lens out
That little fella's gonna make my already-impressive
Daguin DJR 6x real-scary-like...
;D
jayrob said:
I have tried several times to contact Igor. He needs to get one of these bare lenses to compare... Because he said all of the lenses have some of this. Some really bad, some not as bad.
For everyone's info
only, a while back I compiled a few key notes from Igor's feeler thread. It only shows that Igor was aiming for some kind of balance between power & beauty. Frankly, I
can't wait to get my hands on your lens, Jay and if I want
beauty, I'll play with my
Mean Jay Green or one of my other DPSS lasers...
------------------
Anyways, here's the data
I mined a while back from Igor's Feeler thread:
Traveller said:
... I'm not really sure anymore if you are going to choose one or the other...
Okay... now I'm up to speed, or at least
mostly up to speed.
I'll up my order to four (4) of the lenses*. Since you stated that these lenses would only be available via group buys, better safe than sorry
*
The lens being number 8 of the 9 tested
(aka no. 2 of the "final three", aka broadband, aka one bad-ass mofo, aka who else knows what). This based on what I read a, ah,
"few pages back"...:
Just to clear one thing up. There won't be two types of coatings. We could afford two types with any of the first six lenses, but not with these. Luckily these have a broadband coating, which is very good at just around 405nm and 660nm. I did a comparison with a lens coated specifically for 405nm, and there is
less than one percent of a difference, resulting from the difference in reflections.
So the broadband is more than just good enough, especially since as it is, the lens brings more of an increase than expected. When i thought the number would be under 20%, 0.8% more could bring it a bit closer.... But we are over 20% even for diodes with the lowest losses in acrylics.
And if one lens can do both, it's both cheaper, less complicated and more practical for everyone...
So we will have one universal lens instead of two.
There is no need to specify the coating, because the best lens so far comes with a 400-700nm coating. Basically, everyone just needs to figure out how many they want. They will work with any visible wavelength diode, reducing reflections to less than 1% on average and even less with reds and blu rays...
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It's been like this..
Manufacturer 1:
- v1 - the original custom lens, 30 pieces - FAIL - spherical abberations
Manufacturer 2:
- Doesn't even pick up the phone anymore unless caught off guard, in which case they say "next week".
"Manufacturer" 3:
- v2 - first custom lens rescue attempt, 2 samples - FAIL - bubble gum lens?
- v3 - second rescue attempt, 2 samples - WORKS! Oh wait, no it doesn't? Wait, now it does? - FAIL - astigmatic lens/low quality
At this point i realized i was relying too much on too few manufacturers, and went nuts, and started searching for other options, by writing and calling more than ten new manufacturers.
I found:
"Manufacturer" 3's actual manufacturer:
- v4 - third resue attempt, one sample - FAIL - this is a lens? :-/
- v5 - fourth rescue attempt, one sample - FAIL - this was the first lens that was scratched before i got my hands on it, seems like it was made like this :-?
- v6 - fifth rescue attempt, one sample - FAIL - could almost work, has holes in the beam, quality too low
From the whole bunch v3 and v6 were the best, and yet they were horrible... :'(
v1 was and still is the highest quality lens (precision machined lens), but it's spherical, and as such useless for us.
Here end the cheap lenses.
Luckily i also found:
Manufacturer 4:
- wanted to send representatives from France and Germany for a tour of my company, and to convince me to buy quality lenses at 68 EURO each for one piece and 40 EURO each for up to 500 pieces. They said we could talk about the price, once we get to larger quantities. They just didn't seem to understand that 250 pieces is a HUGE quantity for us... But i did get some usefull info.
Manufacturer 5:
- Lens #1 - WORKS!
- Lens #2 - WORKS even better!
- Lens #3 - increases the power the most, but has gaps in the beam - probably rejects from the high quality version. Not suitable for our needs, luckily this one was free. They were probably hoping that we don't need quality and that they could sell their rejects. The quality version costs twice as much as the first two of their lenses.
So we are now actually at lens 7-9, and
v7 (Lens #1) & v8 (Lens #2) are the best so far.... The latter increasing the power the most.
We will go with the 8th custom lens attempt, for max power and thinnest beam. But i am hoping i can also order some of the first lens, because it makes a "cleaner" spot, due to the medium NA clipping the ugly edges of the fast axis, and creates a "fatter" beam..
Lens #2 will bring out all there is, so
the spot shape will depend ONLY on the diode output shape. It's the only way to get all the power out,
and means, that diodes with a weird shape output will create weird shape spots... As diodes get better, so will the spots..
It is usual in pointers to go for a lossy option, such as clipping the output with a low NA of the lens, to make the spot rounder, cleaner and prettier.
- An AixiZ lens for example actually makes a pretty nice, rounded off spot, due to the low NA of 0.3...
- Lens #1 creates a flatter spot, but still with a slightly rounded off fast axis, because the NA is 0.4.
-
Lens #2 has a NA of 0.55 and brings out the entire output and creates a spot in the same shape.
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These [last three lens samples] are high quality precision grade aspherics. Unlike all the others, these were
designed for laser diodes. They even have
diode window thickness compensation! Other than collimating the beam,
their shape also undistorts the spherical abberations caused by the diode window! These are
diffraction limited lenses! Lenses where the size of the foused spot depends only on the wavelength! These are lenses, that could write a disk!
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And finally, a nice synopsis:
NA
Lens #1: 0.40
Lens #2: 0.55
Lens #3: 0.60
FL
Lens #1: 6.30 mm
Lens #2: 4.56 mm
Lens #3: 4.02 mm
Coating
Lens#1: 405nm and 660nm
Lens #2: 405nm and 660nm
Lens #3: 408nm
Power Output Improvement (Based on a 6x diode and Aixiz acrylic lens)
Lens #1: +16.6 %
Lens #2: +24.2 %
Lens #3: No Data
Power Output Improvement (Based on a
high wavelength PHR diode and Aixiz acrylic lens)
Lens #1: +17.5 %
Lens #2: +26.0 %
Lens #3:
+26.0 %
Focusing and Burning (Data still to be properly valuated)
Lens #1: Good?
Lens #2: Some focusing and burning - less than a long FL?
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(IMHO) 
), according to Jay suggestions the first check has been to verify the length of the threaded nut part, just to avoid any risk to push the lens against the diode while screwing the nut deep inside the heat sink (as you can see in Fig. 1, the threaded part of the 405-G-1 nut is 3 mm longer than the AixiZ). In my case the top surface of the diode was 7.2 mm inside the heatsink, so a washer thickness of 0.9 mm was already sufficient for the job. 
