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Seeking links to good knife edging techniques material.

CDBEAM777

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Here is a design I did a few years ago. Just another way to arrange things.

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But...LS...do the Photons not collide with each other....as the beams cross path's ??? Photons " act" like they have mass !!! HAHAHA !! Just some dumb " Beam Humor ":san::san::san: :whistle::whistle:

:wtf: My head hurts...from too much think'in !! ...and then I employ silly humor !!



Beam out
 
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jors

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I have 3 NUBM01T ready to test here :)

Is "zoof angle" = brewster angle? if so, angle is wavelenght dependant....
Which is the magnification with your 'zoof angle'? at +20% losses surely severe angle...

Anyway...I' pretty sure when prism pair is set at 2x magnification (the setup I described) we get faaaaar less losses then 20%...go to test tonight to get some numbers...
so testing losses with...NICHIA green 1w 3-elem + 2x prism pair
 
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CDBEAM777

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I have 3 NUBM01T ready to test here :)

Is "zoof angle" = brewster angle? if so, angle is wavelenght dependant....
Which is the magnification with your 'zoof angle'? at +20% losses surely severe angle...

Anyway...I' pretty sure when prism pair is set at 2x magnification (the setup I described) we get faaaaar less losses then 20%...go to test tonight to get some numbers...
so testing losses with...NICHIA 3-elem + 2x prism pair
Yes...Zoof angle = Brewster angle at approx. 57 degree.

Well....the angle is not severe...but....are we not driven by divergence.

We are comparing two different approaches to optical correction for the astigmatic output of the NUBM01T. To compare these different approaches at parity...divergence equals the playing field. No matter what system I use...I want to correct the beam to deliver a similar Far field geometry.

Using the Anamorphic prism pair...at the standard Zoof angle...57 degree....the aspect correction of the LD Farfield looks to be equal to that of what is obtained with the Cylindrical lens set.

Yes...the more severe the incidence angle is as the beam enters the first prism...the more transmission loss occurs.

Well...my head hurts...even more now.

Again...to compare these two different approaches to optical correction...relative to power loss...we must assume that the Farfield divergence geometry is approx. equal.

Let us know !!! The more testing...the better !!

Thanx,
Beam out
 

logsquared

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But...LS...do the Photons not collide with each other....as the beams cross path's ???
I try to teach my photons to be nice to each other.

Logs you're a genius
Not really. Just necessity. This was before DAve had his 2mm lenses available and before cylinder pairs specifically for diodes were available. The shortest FL -cylinders I could find were -12.5. If I recall the positive cyl was 90mm FL. I had all this wasted space between the BE lenses. The prisms are set to reduce the aperture in this case. I am knifing (stacking horizontally) the SA with 4mm lenses so the 3 beams combined = about 12mm wide. After the prisms it was 5mm wide.
 
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jors

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Yes...Zoof angle = Brewster angle at approx. 57 degree.

Well....the angle is not severe...but....are we not driven by divergence.

We are comparing two different approaches to optical correction for the astigmatic output of the NUBM01T. To compare these different approaches at parity...divergence equals the playing field. No matter what system I use...I want to correct the beam to deliver a similar Far field geometry.

Using the Anamorphic prism pair...at the standard Zoof angle...57 degree....the aspect correction of the LD Farfield looks to be equal to that of what is obtained with the Cylindrical lens set.

Yes...the more severe the incidence angle is as the beam enters the first prism...the more transmission loss occurs.

Well...my head hurts...even more now.

Again...to compare these two different approaches to optical correction...relative to power loss...we must assume that the Farfield divergence geometry is approx. equal.

Let us know !!! The more testing...the better !!

Thanx,
Beam out

Tested right now....GOOD NEWS on power loss and some numbers:

NICHIA NDG7475 (Jordan)+3 elements lens (existotem-ebay)
No correction: (ALL FF MEASUREMENTS @7,6 Meters)
NF 2.2mm (wide) FF 16.5mm(wide) so......1.88mrad

*****Prisms @2x***********
NF 3.2mm (wide) FF 10.5mm(wide) so....0,96mrad
431mW (no prisms) 414mw (prisms) so.... 4% power loss :wave:

*****Prisms @3x***********
NF 4mm (wide) FF 9mm(wide) so....0,65mrad
430mW (no prisms) 406mw (prisms) so.... 6% power loss

those are lasertack prisms:
https://www.lasertack.com/en/anamorphic-prism-pairs

About NUBM01T, and you know better than anyone else, prisms are not efficient for that kind of diodes, just like Reds!!,....so even at crazy severe 6x angles with looses at 30% we have a crappy corrected beam...so absolutely CYLS for this diodes.
(I've read why prisms don't work well with p73 and OClaro, but don't remember where. The reason is divergence BUT other optical issues as well, I think its the same with NUBM01T...so you need severe angles with prisms with great losses. On the other hand, you can see GREEN is easily corrected with minimal losses :)
 
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CDBEAM777

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Interesting !!!!! Perhaps the excellent optics from Lasertrack make the difference !!! That is my hope !!!

If the prism's he offers are specifically coated for 520nm....vs BBar....then that could be the difference !!

What distance is your Far field at ??

Perhaps...the 3 element ( vs the G2) do a better job at collimation....and this....delivers a beam....that the Anamorphics can be adjusted to a 2X....and still get great divergence some options ??????

Very interesting thread !!! Thanx !!!!!

See attached pics of my test bed set up for A prism testing.

Beam out !!





Tested right now....GOOD NEWS on power loose and some numbers:

NICHIA NDG7475 (Jordan)+3 elements lens (existotem-ebay)
No correction: (ALL FF MEASUREMENTS @7,6 Meters)
FF 2.2mm (wide) FF 16.5mm(wide) so......1.88mrad

*****Prisms @2x***********
NF 3.2mm (wide) FF 10.5mm(wide) so....0,96mrad
431mW (no prisms) 414mw (prisms) so.... 4% power loose :wave:

*****Prisms @3x***********
NF 4mm (wide) FF 9mm(wide) so....0,65mrad
430mW (no prisms) 406mw (prisms) so.... 6% power loose

those are lasertack prisms:
https://www.lasertack.com/en/anamorphic-prism-pairs
 

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jors

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yes sorry 7,6mts/25ft
IMHO is about the kind of diode not the prisms...lasertack ones are BB AR coated
hey! great testing setup!!
 
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logsquared

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How much power is lost on the 3 element as compared to the G2? I know I have measured myself but don't remember.
 

jors

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How much power is lost on the 3 element as compared to the G2? I know I have measured myself but don't remember.
Just measured now: 15% lost. but we all know significant % increase with g2 is junk.
Tested with 'chinese' G2
G2: 499mW
3-ele: 425mW
 
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CDBEAM777

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Just measured now: 15% lost. but all we now significant % increase with g2 is junk.
Tested with 'chinese' G2
G2: 499mW
3-ele: 425mW
SO...Therein lies the difference...or...most of it....the G2 vs. the 3 element lens.

I bet we have two things going on here...that explain our different test results.

When using a 3 element lens...clipping or some optical process is in play( more glass ). SO...when the 3 element lens is used...the incidence angle of the first anamorphic prism does not need to be set so severe...to obtain reasonable divergence. So...less severe incidence angle means less power loss. But then...the 3 element lens itself reduces some power via clipping or more glass.

I have seen this Power vs. divergence trade-off B4 ! Always compromises when dealing with Optics !!

WOW...Head spinning yet ?

At any rate....at least for the next 5 minutes....I think the best overall combination remains...the G2 + 6X Cylindrical lenses....for the aspect correction ability of the 6X more than make up for the lesser collimation effect when using the G2.

I just want it all !!! :crackup::crackup::crackup:

Beam out
 
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malford

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It seems like most, if not all, of the discussion for combining beams involves mirrors. Has using lenses been explored? Here's a rough concept I was thinking about. Does anyone know if some form, however different, of this concept would work?

 

RedCowboy

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That lens wont do that, it will expand those beams like crazy, make them very wide and expand the divergence.

It could make a nice liquid sky sheet of light.
 

RedCowboy

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It says it right there, photorefractive beam coupling, let's look it up, it's not a concave cyl, that will expand the beam.
It's possibly a bragg grate combiner.
 
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