LOL
When I build my cone of 8 beams I will have them all intersecting at about a foot away or where ever I need ( it's all adjustable ) and then I can use 8 small mirrors to reflect the small circle of beams back through the center of my rig which has open air for this purpose, all 8 beams in a tight little circle/cluster and with the right concave mirror that circle could be pretty tight...........more of a + and x overlapped where all the bars come together which means each laser would be rotated so the bars point to center.......I really want to do c-lens correction on 8 x ndb7A75's and use them in my cone of beams set up and with the right concave mirror have a nifty little circle/cluster of searing blue glory............and if the divergence of my bundle from my concave mirror is not tight enough then I will lens that to infinity point.
Note: With a concave mirror it will need to be centered and all the beams will need to be rotated so that they are all in line to center, like pedals of a flower or spokes of a wagon wheel and each beam center will need to be the same height and same .......well it all needs to be symmetrical.......with a concave mirror you would intersect the beams just after they all cross over and are expanding again........but with 8 individual mirrors there's room for slop and you can intersect the cone in or out, just align each corrected beam to the finish line/distant point from the mirror point.
With the concave it's the ring dia. to cone length that has to match the concave mirror so the position of the mirror and cone length would be adjusted to get a tight cluster/beam out.
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