OPT Lasers Cylindric lenses - NUBM44 beam correction tests

I've been working on my Cylindrical Lens Pair Fast Axis Correction Mount and I'm about half way done, ElectricPlasma has finished machining and shipped the one part I couldn't make myself (Thanks ElectricPlasma !) and I have most of the Cylindrical Lens Pairs I'm going to put to the test first by trying to replicate the work in this thread done by Milos and then test that against the OPT 6X lens pair I have coming !

We were testing some other lenses available on the market. And why we choose this shape not another, here are the answers:

1. 12x12 allows to use the same valley shaper t omover one lens versus another, you do nto need 12mm and then 8mm.
2. 12mm is smaller than any diode housing maybe despite soem 3,8mm didoes and big enough to hold in hands/fingers
3. Additional thickness do not affect efficiency and when the lens stand on the surface it is harder to make the mfall down, they are just much more stable
4. Total place needed for them to work is 42mm. It is possible to make this distance smaller with different curves but then setting the lens is much harder so we decide about this distance to be optimal.
5. Efficiency is around 99,8% for 450-650

I ordered my 6x pair (+ a NDG7475) to put with my uRGB package please Mateusz Thanks !

99.8% efficiency is very good, I also need a wave plate and PBS cube to combine then correct 2 beams into 1, I have some Chinese PBS cubes, but I would rather use all OPT parts, also if OPT made a beam expander that would be great, maybe 7X or so ?

Any plans for a BE ?

We are not using beam expanders so we were not planning to produce them. But is it possible if there is enough demand on the market.

Accutronitis said:

I've been working on my Cylindrical Lens Pair Fast Axis Correction Mount and I'm about half way done, ElectricPlasma has finished machining and shipped the one part I couldn't make myself (Thanks ElectricPlasma !) and I have most of the Cylindrical Lens Pairs I'm going to put to the test first by trying to replicate the work in this thread done by Milos and then test that against the OPT 6X lens pair I have coming !

Click to expand...

Cool, I mount mine as close to the G2 as possible because it's a tight fit into the 3X expander if you choose to add it, but man is it worth it.

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Tomorrows System said:

We are not using beam expanders so we were not planning to produce them. But is it possible if there is enough demand on the market.

Click to expand...

I wish we were not so slow here, I would love to have some or even a single larger ready made BE, after fast axis correction they are amazing and PBS/wave plate combining a pair of 44's corrected then into a BE would be fun to put through it's paces, I know holding a corrected 44 in each hand makes lots of fire but it's tricky, having it in 1 package will be nice.

I would buy a BE, likely several and will probably try out a pair of your 6X, I already have several ATM or I would jump straight on it, if the output beam diameter is better then that's an advantage for the 3X I use a lot of, I am eyeballing some Chinese BE's though hopefully to accommodate some KE beams, you have a 10 diode unit that looks great, but batteries and heat make me think that 4 x 44's would be enough for some fun.

I will wait and see what the results are because I have 4 pairs of 6X that are not in use and well, it all adds up. But I would buy some larger BE's I would even pre order.

I made some more progress on my Cylindrical Lens Pair Fast Axis Correction Mount and the first of two Cylindrical Lens setups i'm going to try with the first being the Milos setup giving the fast axes a 12x squeeze.....

RedCowboy said:

Cool, I mount mine as close to the G2 as possible because it's a tight fit into the 3X expander if you choose to add it, but man is it worth it.

Click to expand...

I contacted them about that very thing .....

How close to the collimator should the first cylindrical lens be for best results ?

Click to expand...

and this is their response...

it is not very important can be 1cm can be 5 cm.

Click to expand...

Tomorrows System said:

We are not using beam expanders so we were not planning to produce them. But is it possible if there is enough demand on the market.

Click to expand...

OMG how cool would a OPT beam expander be !!!!! Could you imagine ?!?

I wana know why we call cylindrical lens "Fast axis correction" however they correct the slow axis of the laser diode ? Fast axis is already singlemode and focusable to a thin line with the collimator.
It's a mistake ? because the reference is the raw laserdiode axis. After the collimator the fast axis become slow and the slow become fast but by convention the name can't change.

(https://www.photonlexicon.com/forum...es-Fast-Axis-Slow-Axis-demystified-discussion)

Serveurperso said:

I wana know why we call cylindrical lens "Fast axis correction" however they correct the slow axis of the laser diode ? Fast axis is already singlemode and focusable to a thin line with the collimator.
It's a mistake ? because the reference is the raw laserdiode axis. After the collimator the fast axis become slow and the slow become fast but by convention the name can't change.

(https://www.photonlexicon.com/forum...es-Fast-Axis-Slow-Axis-demystified-discussion)

Click to expand...

Ya I don't know why that is either ? I just go with the flow if you know what I mean......

I think this is a mistake because lens reverse the appearance of axis.

Now I understand why we say "over corrected" for slow axis.
The slow axis is just returned by the collator (line from die projected left to right and right to left)
(This first lens must be near the diode to capture all light from the diode fast axis, and this fast axis is singlemode and collimated to a line)

The cylindrical is a 1 axis tunable beam expander for the slow axis
cylindrical are SAC and not FAC!

Serveurperso said:

I think this is a mistake because lens reverse the appearance of axis.
Now I understand why we say "over corrected" for slow axis.
The slow axis is just returned by the collator (line from die projected left to right and right to left)
(and the fast axis is singlemode and collimated to a line)

The cylindrical is a 1 axis tunable beam expander for the slow axis

Click to expand...

I think it is like what you said and the cyl lens pair is acting like a beam expander and it is expanding that 1 axis wider after leaves the collimator and refocuses it back to a point at 50 feet like the collimator does with the other axis because the thin part of the line at 50 feet leaves the collimator wide and it gets narrower as it heads out to 50 feet and the other axis starts out narrow and gets wider as it heads out to 50 feet and ends up being the very wide part of the thin line !

If that makes any sense ?






Just a quick update on the addition of the Cylindrical Lens Pair Fast Axis Correction to my 44 and how it's progressing. The cyl lens pair mount is ready to attach to the heat sink but I was trying to figure out how to make sure the beam was aligned down the center of the mount tube and then it hit me ! heck i'll just use the same tubing as the mount is made of only very long and slide it into the mount and then just look at how the beam exits the long end of the tube ! Worked like a charm !

Well I have everything I need now to make the mount permanent, Time to attach it !

I'm using JB Weld to attach it while checking the alignment for time to time, I've used JB Weld many times before and it has never failed me !





So far, so good......





The lens setup is not yet set in stone, I'm using double backed tape like milos did.....




The JB Weld is cure enough for me to remove the mount tube !




Now let that cure for around 36 hour "until it hardened" so i'm let it sit !

The best is to get à square beam on output lens of the last output lens.
To get a square beam on output, 6x is sufficient or the 12x assembly do better ?

Accutronitis said:

Well I have everything I need now to make the mount permanent, Time to attach it !

I'm using JB Weld to attach it while checking the alignment for time to time, I've used JB Weld many times before and it has never failed me !





So far, so good......





The lens setup is not yet set in stone, I'm using double backed tape like milos did.....




The JB Weld is cure enough for me to remove the mount tube !




Now let that cure for around 36 hour "until it hardened" so i'm let it sit !

Click to expand...

Very impressive work Accutronitis, looking forward to the finished product. :gj: and the beamshots

Serveurperso said:

The best is to get à square beam on output lens of the last output lens.
To get a square beam on output, 6x is sufficient or the 12x assembly do better ?

Click to expand...

I'm sorry but I'm not sure what your saying ?

Amazing work. I'm french with bad english:s
To maximise the beam expansion of each axis on the output lens of a beam expander I need a squared beam.