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Multiple beams

CDBEAM777

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The factory integrated GBall focus is good on 05 diodes and many but not all 06 diodes and this block has good focus for Gballs ( Yes I inadvertently burned my white ceiling just a little, I will paint it. ) but the 08 diodes I have had many with awful factory focus so 05 which is also the least expensive and can be driven hard looks good.......I also wonder about the Osram 24 diode arrays as the diodes should be smaller and have better divergence. I am leaning towards the Osram array and am very tempted to order one, I might break any moment.

There are some larger projectors that use 4 blocks set up as 2 banks of 2 and they use this optical device to fill the gaps with the adjacent beams, so like a 32 beam in the space of a 16 double IINM.


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Well I made an offer and received a counter on the Osram array, they are not as strong as the N-brand 31/34 but IDC about the highest output as much as the individual chips divergence, I just bought one @ 160.00 so if you make an offer you should be able to get that deal or maybe better ( I might have turned down a slightly better offer weeks ago, can't recall ATM )...... I will end up building with both when I get a 2nd 05 array ( I will wait for a bargain ) but my Osram array is ordered and my fingers are crossed that it will at least be some fun with a big convex-concave arrangement. :)

Indeed....Hammer that BEAM !!! SO...Are you gonna do two (2)....side by side....like my cartoon above...ALL entering the Convex....then the Concave...I mean...look at some of the stackage pics...See pic..... "Big Red Telescope".....Just many , many Red diodes....stacked and knife edged.....really....the same as two (2) of these blocks....Just an order of magnitude for more space and alignment headaches !!!!! This is simple.......Really !!!!
This seems too simple....What am I missing !!! HHHmmmmmmmm ???? What is the divergence of EACH individual beam ????? What do you predict the "WOOD" to be !!! ( Watts Out Of Door ) HAHAHAHAHA !!!! "Onward to Infinity "!!!

CDBeam
 

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RedCowboy

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The divergence of the beams, mainly the uneven and aggressive fast axis divergence of each individual laser is an issue, but rather than attempting to correct each beam I was thinking about a concave - convex pair and see what I get.......I expect it will look cool, like a big fire hose sized beam.........you have seen the 100w that Trinh built right ?

I would like to make a quad array and set each array so that they converge at infinity or the most distant visible waist ( probably using only the stock gang lens and a long FL lens ) but 1st I just want one in hand to work with, I really want to work with the coming green arrays as these will be all about dazzling aesthetics rather than distance burning.

Another thought is maybe we can talk to the Chinese sellers about having lengths of fiber set across the rows of emitters ( with the gang lens removed ) then possibly reset the gang lens or use a grid of 24 new lenses to produce a better quality albeit a wide beam that we can lens down to a point much better.

Anyway this will be my 1st of these new arrays so it likely won't be my most glorious albeit physically large setup........I am already thinking about a battery pack worn like an over the shoulder bag or even a backpack leaving more room for a shouldered device possibly housing 7 or 9 arrays, 1 in the center surrounded by 6-8 others all lensed that will be adjusted to all converge at infinity.........in time we will be able to buy low hour gently used but " old hat " projectors and do all kinds of this fun stuff on the cheap, so plan big even if we end up having to wait a while to build it all.

When we have RG and B arrays in hand.......a big white fire hose sized beam ?


BTW a little bit of moving air makes a big difference in temp control, a small fan behind a finned sink that each array mounts to will negate the need for bulky sinks that only saturate anyway, it's time for the fans the stay in our plans. :)

P.S. I am also looking at a bunch of 7A75's to c-lens correct and knife edge then employ a home made beam expander, I have made an offer on a couple dozen NOS diodes and now I wish I had bought more of your GB 6X pairs, the pairs from Poland are pricey, I'm still amassing parts but this is the right way to do it, it's just that the gang lens arrays are cheap per watt and too much fun to resist, but I know it's not the right way to run a railroad.
 
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CDBEAM777

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HAHAHAHAHA.....The MOST epic Green unit I am now working on has Two (2) fans.... Temp Monitors , VDC Meters....and well....Many diodes !!!...

RC....It sounds like you also have enough projects till 2030 !!!....YIKES....Go BIG....or Go Home !!! Really Fun stuff !!!!!
Also....On the Railroad comment....I dunno....Your Blue arrays look pretty GOOD !!!

CDBeam
 

RedCowboy

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Pretty to look at and fun in the near field they are, but we aren't going to have any real burning reach with this horrid uneven divergence and dismal beam quality, makes me want to knife edge a couple hundred 405's.......but the MM blues are fun........wee

The little screamer fan from a 140 projector keeps this block cool just blowing on it, without it.......gets hot fast, just a little moving air makes the difference.



The alignment and focus is not bad for what it is.

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CDBEAM777

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Hmmmmm.....Interesting !!! Thanx for pics !!!! Well....As usual.....there is compromise with all Engineering Solutions !!! I will choose the least initial individual LD divergence in a Block selection!!! Hmmm Unfortunately...that information is limited !!! Thoughts on this RC ??? Block raw output is also a factor in selection, but is secondary to divergence metrics.

A " Firehose " geometry of many beams....well....OK....but....mmmm....say two (2) blocks....so....2 x 8 = 16 LD ....16 x 5W = 80 W ??????? That is a good deal of Photons for a larger beam geometry !! RC.... what is the rated output of each block ??? Are my figures correct ??? Then....we will have optics loss....SWAG....5% to 7% ???

SO...as far as power....Maybe consider the new generation Graphene Cells ??? $$$$ though !!!

CDBeam
 
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RedCowboy

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The nubm05 blocks are basically ndb7a75 diodes with GBall caps.
 
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RedCowboy

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Would be better to mount window can diodes by drilling pin holes in an aluminum plate and mounting ( thermally bonding ) them flat, then drill and tap a lens plate to set over your grid of diodes and use conventional lenses, even better would be to knife edge them, and better still correct each beam prior to it's KE mirror....... but this is all about making do with what's available for cheap and actually it looks pretty good the way it is as far as looking goes.

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As you can see the bundle looks good at 1st glance but observing the spot/s they are 6mm thick by 30mm long @ 5 meters and spread over an area 25mm by 100mm and are uncorrected so with a big beam expander it could be pretty to look at but not a distance burner......well with a really big BE but the beams are still uncorrected so.....
Really should start on a knife edge array but I do like the look of multiple beams all running together and when we get the green arrays.......well quantity has a quality of it's own, that said I have an Osram 24 diode array ordered, it would be nice if the individual chip divergence was more 7875 like but just starting closer together will help some but not enough to compete with doing it right.

Shining down into my empty backyard at night the beam bundle looks neat, but the spot is a cluster of bars that gets bigger the further it goes.

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RedCowboy

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I set up an expedited beam expander on my 05 block running @ 1.5A and was able to get a nice little 1/4 inch cluster burning @ 5 feet, with some different optics I think I could put it to work on my favorite targets 15-20 feet away, actually these lenses will work but the further away we zoom the bigger the spot/cluster............, I still plan to c-lens correct and knife edge several 7A75's and use a big beam expander but this set up should make for an aesthetically pleasing infinity focus , I can't wait until we get the 25 x 30mm green arrays, I think with maybe a 75-100mm wide beam expander we could make a good looking far field spot with a 20-24 emitter 525nm array made from nugm03 emitters layed out in a 25 x 30mm area ( estimate based on nubm31 ) .............Nobody else has used a big BE on the new arrays yet that I know of and I think it's going to look amazing for what it is.:D we shall see.

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The only reason this 1/4 inch plywood didn't burn up is the cluster punched through.........I'm falling in love with beam expanders all over again......Note* This is at only 1.5A
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RedCowboy

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Here are some pics from 15 feet with the expedited beam expander, it's not bad, there is one flyer to the right of the cluster, one of the 8 is slightly mis-aligned and that compounds with distance, but for hand made arrays and c-lens corrected knife edge arrays a big BE could really do some magic.......I have a renewed vigor for big beam expanders and am thinking about having some made with AR coated optics.

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5 foot cluster is lower right and 15 foot cluster is center/left.....you can see the one flyer beam to the right of the 15 foot cluster.
Note* This is still @ only 1.5A
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gazer101

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Is there any way to use a fresnel lens like a giant flat convex lens for focusing a laser array down to a point? Would allow for more portable laser-array-focusing optics
 

RedCowboy

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Is there any way to use a fresnel lens like a giant flat convex lens for focusing a laser array down to a point? Would allow for more portable laser-array-focusing optics

A Fresnel lens can't be accurate enough to reach the diffraction limit of a coherent light source such as a laser, so a Fresnel lens can't be used to cleanly collimate a laser or an array of lasers as well as glass and would actually scatter light from a beam or bundle of beams.


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I am not impressed with the Osram array, it's good for up close fun when focused to a point through a lens in addition to the factory gang lens but the beams are poorly focused through the factory gang lens and kind of sloppy overall, fair amount of lens flair too......sorry I didn't take more pics but during testing I made a polarity mistake and blew one of the rows and decided to open it up and look around inside because I wouldn't use it with a missing row, just feels wrong, if you are going to buy one of these cluster-humps I would get the nub-31/34 based on what I have seen.


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Alaskan

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Nice thread, those blue beams lined up well. You sure have your blue burning laser diode tech worked out, no one else in this forum has done so much with the 44's. I didn't realize there were so many photo's in this thread until now, I guess they were still loading the last time through this thread, good work. Now I have to find some of those wooden pop sickle sticks and try that with my 532 nm DPSS :)
 

RedCowboy

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NDB7875 with a G2 .......even with a 3E will cut through the penny thick popcycle sticks.....not lickidy split but with a steady hand it will do the job, so if you set a basic bi-convex household magnifying glass lens in front of your 10W dpss to make a sub MM waist it should make quick work of cutting them.
 

Buffo

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There was a discussion on PhotonLexicon back in 2006 about producing a custom "axicon" optic that might be helpful to your build. (Despite the fact that there are axicon lenses, that's not what this was about.) The idea was to start with a rod with a conical tip and then grind 4 (or more) symmetrical flat faces into the tapered tip. Then cut off the tip, mount it on a backing plate, and drop the whole thing in a vacuum deposition oven to coat those flat faces with dielectric film to make them into high-efficiency first-surface mirrors.

Now you could aim an array of 4 (or more) diodes at those faces and the resulting output beam would be a tightly-packed cluster of collimated beams that were perfectly parallel to each other - no knife-edge mirrors required. There was even talk about drilling out the middle of the rod so you had room for a central beam.

The project never really went anywhere, but the physics were sound and the actual manufacturing process was fairly well described. I think something like this could still be done affordably, and it would certainly simplify any optical arrangement where you needed to combine several diodes together into a single, composite beam.

Food for thought...

Adam
 

CDBEAM777

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See this Thread....


A More advanced version of this IS now about 50% complete !!! C-19 slowed things down !!! The name of this project is...
" The Green Kraken " Alaskan has commissioned me to design and build. I MUST get his approval to post ANY details...but...I assure you...THIS will be completed by Fall 2020....and will be Epic !! We are hopeful to deliver 10.4 W out the front door in a small beam pattern array.
Hold on to your hat !! CDBeam
 




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