New! Sharp Diodes 1W 520nm & 5W 455nm & +2W 638nm

[CDBEAM777]

Ditch the G8. use just the 75mm FL.

Ye...I will do that shortly !!! CDBeam

 

[CDBEAM777]

I know that go back and read my posts. I have been trying for 10 pages to explain how these work.

But it should offer much improvement with simple optics. Much more compact and easy to build compared to cylinder pair.

Well...For sure...The C-lens Optics...When combined with a G8 and the Blue FAC....well....I can get the geometry down to a 1.25 mRad....BUT....The Geometry of the Mid Field Beam, say @ 14M....is a compact " S " shaped....and I am still trying to correct this !!! I should add that I truly dislike the " S" shape ! Adjusting for CLens Pitch, PCX=> PCV distance. and distance from LD => CLens set....no combination has yet to eliminate this Abberation. It is very possible, NO improvement can be realized !

Anyway...I will trial the 75mm EFL Convex with NO Collimation lens. I have the lens....so...FREE try !! LS...If we must allow the Blue FAC Raw output to expand....THEN Multiply the Fast axis to leverage and achieve reduced divergence in the Mid/Far Field...GREAT....OK....But...In my Supercar build...I achieved a very good divergence with the combination; NUBM044 + G8 + 6X CLens set..

So far...we are still trying to tame this Blue FAC... just because....Well...I have a personal reason.....BUT...really....WHY ??? The most powerful NUBM044 has been tamed....IMNSHO....with almost NO ABBERATION....The Green FAC is a keeper with 3E Collimation....and...I have not yet started to experiment with the Red Fac...but I expect it to act as the Blue FAC. Then again....this hobby is full of surprises….And just when I start to get...er...ah...overconfident....I get slammed into the Floor of Humility !!! Oh Well !! Will report back, CDBeam

ADDED: We will never achieve a perfect X=Y aspect....well not with the Standard PNP junction configuration. We will get closer to X=Y...but never perfect. The greater the beam propagation....the more visible this "X does not equal Y" condition will become apparent !!. I again refer to the great benefit of Parallax View !!! It is a good thing !!!

 

[logsquared]

Ye...I will do that shortly !!! CDBeam

Bob you're killing me Put that lens in front of it. The crowd is getting restless.

Well...For sure...The C-lens Optics...When combined with a G8 and the Blue FAC....well....I can get the geometry down to a 1.25 mRad....BUT....The Geometry of the Mid Field Beam, say @ 14M....is a compact " S " shaped....and I am still trying to correct this !!! I should add that I truly dislike the " S" shape ! Adjusting for CLens Pitch, PCX=> PCV distance. and distance from LD => CLens set....no combination has yet to eliminate this Abberation. It is very possible, NO improvement can be realized !

Sounds like a rotation issue? Maybe the FAC is slightly glued of axis?

Anyway...I will trial the 75mm EFL Convex with NO Collimation lens. I have the lens....so...FREE try !! LS...If we must allow the Blue FAC Raw output to expand....THEN Multiply the Fast axis to leverage and achieve reduced divergence in the Mid/Far Field...GREAT....OK....But...In my Synthesia build...I achieved a very good divergence with the combination; NUBM044 + G8 + 6X CLens set..

I'm not 100% sure I follow?

So say with the G8 (8mm FL) the SA or the wide part of the Bar image on the wall is corrected with a 6x clens set. Lets look at what is happening.... The 6X reduces the divergence of the 8mm fl by expanding the beam. So, if we take 8mm and multiple by 6? We get 48. So if we put a 48mm FL lens in front of a raw diode we could get the same effect of the G8 + 6X with just one lens in that axis. The problem with this is the RAW FA expands too fast so most of the light wont strike the lens at 48mm distance. Here is where the FAC comes in to play. It reduces the spread of the raw diode FA only, so both axis fit on the lens 48mm away.

Further we can choose the distance away from the diode where the diameter is what we want and put a lens of that FL there.

 

[RedCowboy]

Yep the longer FL lens makes it work, the spot is not perfectly square but great tight spot, burning this shelf board 5 meters away at only 300ma

 

[CDBEAM777]

Nice work RC ! Is there a Colli on the rig ???

Well...The 75mm...is not long enough FL !! As one continues to move the lens back....the Mid Field spot is reducing...but, I ran out of room !! I could Not move the lens back any further...without out masking the beam...Maybe a 100 EFL or 150 EFL ??? BUT...BUT

I have managed to adjust the C-Lenses....to achieve NO " S" shape. The geometry is 21mm Vertical by 15mm Horizontal.. @ 14M Not perfect...but much better. This was done with a G8 Colli.....Maybe I will switch out to a 3E and see what that does. Have more 3E coming from DTR.

Whata PITA !!! What Fun at the same time !!!


CDBeam

 

[RedCowboy]

No it's the raw output hitting my plano convex lens, the lens has the round edges trimmed off but it is a plano convex and you can see how big the beam starts at the lens ( about 1 inch square ) then tapers to the point at 5 meters where I have it focused.

This is improved over what the raw output would be at this point of about 5 inches away.

 

[Alaskan]

So, we can use these FAC diodes for either burners or a beam collimated to infinity with your setup RCB?

 

[Lifetime17]

No it's the raw output hitting my plano convex lens, the lens has the round edges trimmed off but it is a plano convex and you can see how big the beam starts at the lens ( about 1 inch square ) then tapers to the point at 5 meters where I have it focused.

This is improved over what the raw output would be at this point of about 5 inches away.


View attachment 67651

Hi LPF,
Amazing all you guys figured this out , I been following this thread for an outcome . many smart and savvy folks here with determination to solve these issues. Hats off to you.
Rich

 

[GSS]

Hi LPF,
Amazing all you guys figured this out , I been following this thread for an outcome . many smart and savvy folks here with determination to solve these issues. Hats off to you.
Rich

Yup,
makes me feel more stupid than usual

 

[RedCowboy]

Your not going to get a thin beam like you would want for a projector but for a further reaching burner or distance pointer you could use a housing like a zoom flashlight to hold your larger lens and zoom to point of focus, it's like what you get from a beam expander but it is an improvement over stock.

For making the most use of your host diameter use a lens with a thick rim, basically a wider lens with the center cut out, like a doughnut hole and you use the center part that was in the hole, that way you get the benefit of a wider lens in less space.
You will need more working distance to focus from near to far than just turning a threaded lens barrel.
With a 30mm PCX at 75mm FL I would guess a couple inches of travel.......estimate. Will take some fine tuning, the wider the lens and longer the FL the tighter your spot will be.

 

[Lifetime17]

Hi Red all in all superb work and getting it done
Rich

 

[RedCowboy]

Just having a little fun, I still have a lot to learn but that's a big part of the fun and we all enjoy more of the hobby together than we could alone.

 

[Alaskan]

Quote: Tin hat bowtie child
From what I’m coming to see, FAC corrected diodes are not the answer for laser pointers, that their use is for two purposes; squaring the beam prior to a tight pin-point focus for more uniform burning and for IR pump diodes to better focus a more uniform beam into a DPSS crystal, otherwise not useful in pointers. Better to use cylinder pairs or a prism pair to square up the beam, correct?

Edit: Also, when expanding the slow axis of a laser diode by any method to square the appearance of the beam close in only increases the difference of the divergence between each axis, so in the great distance the beam pattern becomes more of a bar shape than before, is this not also true?

OK, great news, then it appears we can indeed use FAC corrected diodes, just that we need to use longer FL larger diameter lenses. Too bad we can't use our ~6 mm diameter lenses to knife edge together with smaller beam diameters without adding additional corrective optics. Two steps forward and one back, but at least a step forward overall

 

[Coonie]

That's what I've been saying... use a long focal length lens...

 

[kecked]

Should be good for making beam fans and lumia.

 

[paul1598419]

Aren't these diodes more expensive than just the plain diodes available to us? I just don't see the utility in using them for much except maybe as an engraver. Seems like you must jump through a lot of hoops to get a reasonably collimated beam while the stock diodes do that much more easily. Still can't see the what is to be gained over using cyl lenses.