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FrozenGate by Avery

OPT Lasers Cylindric lenses - NUBM44 beam correction tests

Thanks for the tests. Interesting convergance issues. Maybe it is best to simplify and start measuring slowly. I have convergence issues only at about 10feet when doing 9x squeeze using two 3x concave lenses.

Lets maybe set the distance at 10m and see exactly what best you can get projected at that distance. Maybe take a photo against yellow paper of flat gray surface with ruler.

All these 2x, 3x, 4x, and 6x square or rectangular lenses we use to shrink the beam and put right in front of the G2 lens are concave. Convex is on the end. Not sure what you mean.

Could you give some measurements in millimeters. Its really hard to keep the track with all the fractions :-( Also, what is the beam output diameter? What power output are you using?

Burn marks are not best way to measure as the center is always the hottest.
 
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In order to achieve best possible beam, you have to focus G2 as best possible against target as far as possible. Not have it converge at 5m. Convergence is imediately followed by divergence and not just tighter beam for the next set of lenses. This will deffinitely be a limited useful range beam no matter what lenses get in front of it.

In order for us to get the right setup we have to start step by step best beam against infinity with G2 first for example. Only then we can compare next set of lenses and find what works best against infinite distance.

That is unless you wanna tighten the beam, plus focus it to a speciffic spot at certain distance "X" for burning.

I might have understood you wrong though.

i just want to find best set of lenses for tightest beam at infinity.

Im hoping to reach or breach my hoal of 0.7mRad
 
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Thats nice. Do you mind checking power output and if it is indeed as good as the G2 from DTR shop?

Also, could you project the line at distance X (something like 5 or 10m) and measure the length of the projected line. Kind of like what i did at the beginning of this thread. Photo would be nice too. That way we can compare.


thank you.
 
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Thats cool.

No, I'll stick with what i have for now.

I have 4x squeeze lens coming in and this is is. I am looking forward to test it with my OPT Lasers 3x and 2x lenses and produce 12x squeeze. I can't wait to see the form of the beam at this ratio. I will be able to do a 16x test as well.

will post then

cheers
 
After long delay, ( working on it about 1.5h per week or per two weeks) I had major sucess, and most likely a final setup I will stick with.

I'm getting 0.3-0.5mRad !!!!!!

Here is a nice shot I tok on the end of the experimentation session on Friday. I will post more results and photos of the latest setup very soon.

cheers

s577YjM.jpg
 
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Ok, here is the setup I used combining a 3x from OPT lasers, and a 4x from Lasershow Parts. Basically it gives the best squeeze of the beam for this diode out of all I tested so far.
I tested them with Lasershow's, and then with the OPT's plano convex lens on the front.

Here is setup with Lasershow's plano convex front lens.

WemBTTl.jpg


and here is the setup with OPT Lasers Plano convex front lens.

vIrmXo3.jpg



Both setups basically produced a 12x squeeze, but the difference was in the front and final piece of glass where OPT lasers produced an output beam of nearly 6mm (5.5mm-6mm) but a bigger necessary distance from the cylindric plano concave 4x+3x set.

The Lasershow's front lens although allowing for an overall shorter setup, it produced a tighter output beam of 4mm!

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So after having now tested 6x, 9x, 12x and an 18x squeez of the NUBM44 diode beam coming out of the G2 lens, the clear winner is a 12x setup combining one OPT Lasers 3x Plano Concave lens flat back to flat back against one 4x Plano concave lens from Lasershow Parts, and correcting this beam with the final Plano convex lens that came with 3x lens from OPT lasers.


The beam widthe at the exit is about 5.5-6mm( more like 6mm)
yPerSq2.jpg



Divergence results and beam shape:

Drumm rollLL....

An amazing 0.4mRad considering beam is 5.5mm, or 0.35mRad if we call it a 6mm which is probably more true. Its kind of hard to measure it that precisely!!
I have checked the beam throughout its path of 10m, as well as at the distance of 30m. It is not converging or transforming in any way.

Im very happy.

Here is a picture of the projected line at 10m. It looks better in real life, but I haven't figure out yet how to take a decent photo of it. As soon as I do, I will take more shots, and at 30m as well.

8QLNYd3.jpg




I feel like this is it now. I never had a laser with below 0.9mRad divergence, and now, ironically, it is coming out of the most diverging and the most powerful diode we have for this hobby. Its amazing.

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From your aperture to 10 meters looks good.

Sometimes I will actually run negative divergence to about 75% aperture beam area at the 2-3 meters mark, then it opens back up, do you carry that all the way or does it shrink and then go positive again?

Either way it's a good result. +5

p.s. What power numbers are you getting? How about some burning videos :D
I have been doubling up with a corrected 44 in each hand rested on the edge with my elbows to the outside and braced against each other.

12 watts is addictive, I want more.

Maybe with good correction combining will work better, I bet a beam expander would do some magic after correction, I have been thinking about SANWU's 3X but still have some questions about AR coating.
 
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Thanks.

I checked the beam throughout the path from laser to 10m wall and it only slowly diverges at 0.4mRad rate. No converging.
 
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Great work ! Both LSP and OPT are very good to work with !! I am not clear what the Raypath is for the three (3) lens set up...but....who cares !!! It works great !!!....and at that Far field of 10M....to have such a tight beam....with minimal artifacts !!who could ask for more !!!!
Based on this work....I will consider to give the 044E another chance !! Thank you for your efforts.
CDBEAM=======>
 
I just ordered one of these, they had been out of stock last time I checked.

http://jetlasers.org/accessories/15-10x-adjustable-beam-expander.html

There looks to be ample width to accept our corrected beams, the 44 makes good power but even 6 watts has it's limits, so being able to snug it down at range could be useful.

I don't have a LPM but Lifetime17 and I have coined the hanging shirt at 32 feet test LOL.
Feel free to post a result for comparison, but with an expander of the 3 I think your setup will do the best, I tuned mine to be more useful as is for the now, but it's the knowledge that's the rare part, the physical is easier. :beer:
 
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Hi Milos,

I am happy that your idea is working. I soon will finish a device with 2 PBSed 07e and a similar set at the end.


BTW CDBEAM, I once calculated the Raypath with a program from one of Alaskan´s posts, here is citation:

"According to this program, you can get 7.5x expansion with 3 lenses from 3x sets (at assumption that focal lenths are -10 and 30mm the lens separations will be 5 and 24mm to get collimated beam).

https://lightmachinery.com/optical-d...yUaPB1sc6rdN2w

If lens separations are 20 and 22.5mm the expansion will become 12x."

Maybe 4x works better because lower glass thickness allows for concave curvatures to be closer?
 
This is all great information. I am very interested in knowing the power loss through all these optics, though. It would be interesting to compare a G2 only power and then the corrected beam power.
 
I once mesured NUBM44 in Cu-module with G-2 from DTR and did not notice any power loss after OPT C-lenses pair. But my LPM head was too close to the limit at 7W.

With a similar 3 lens set only from OPT 3x lenses (I am checking it now PBSing NUBM07es) since OPT lenses are too thick (5mm), there is glowing at both sides of the 2nd PCC, so should be loss, but it might only be from sidelines and not from main central spot.
 
Hello,

Long time I was not here. Overal efficiency of this lens is 99,7% sometimes even better. Using two lens it is 99,4% quaranteed. We payed quite a lot for this coating.
 
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