Mitsubishi ML520G71...Red Holy Grail or Flashlight Fail ??

[kiyoukan]

4mm beams can not fit on 5mm mirrors.
5mm mirrors can only take a a 3.6mm beam
6mm mirrors can take about about a 4.6mm beam.

[Fenechlaser]

4mm beams can not fit on 5mm mirrors.

Does this help to cleave off part of the wings?

[kiyoukan]

Yes it kinda acts as a pin hole it will force cut the beam down to around 3.6mm from 4mm.

[planters]

Sorry about the confusion. When I wrote about a 5mm scanner, I meant a 5mm aperture scanner (7mm mirrors) But the question remains. Do the near field beams largely overlap in the near field and hence require less than a simple summation of their widths to fit on a scanner?

I know the whole issue of divergence nomenclature was beaten to death already, but when I compare beams, an 8.5mm square at 14' is as large as the largest dimension of my UNCORRECTED 445 laser and of course I do correct it.

A 4 diode module with a PBS will still require two primary beams to fit on a practical scanner. If they are limited to 2mmx4mm the divergence is still pretty high

[kiyoukan]

im not sure if i follow what you are asking.
When i stack my 2 diodes one is at 28mm high the other at 30mm
They form a almost perfect 4mm square at aperture.
And the square remains almost perfect down the whole beam.
The vertical wings make it a bit hard to get a 100% perfect measurement.
You might need to draw me a picture.

[planters]

So to clarify your set up...
What are the near field dimensions of each of your two primary beams either prior to the PBS or after the cylinder lenses. What are the dimensions of the two beam combination at the same positions? What are the dimensions of the primary and of the combined beams at a given far field distance. I'm trying to understand how the two beams are stacking and what the effect of adding a second beam to a primary beam is regarding the dimensions of the combined beam.

When you mentioned 28mm and 30mm it makes me think that your two beams are adjacent where you measured them; neither overlapping nor separated by any space. If that is true then unless you are knife edging them a full 2mm apart they must be diverging as they move through the system. Am I making this any clearer? Or am I just adding to the confusion?

[kiyoukan]

Here is the image of my setup

The first beam passes over the mirror at 30mm the second is knifed edged at 28mm.
Near field they form a 4mm square.

Far field it looks like this

But if i only run 1 diode it is a 4mm wide by 2mm tall beam so i stack them, i could stack them a tiny bit closer but decided not to.
Remember i do vertical stacking, the only harder part of it is getting the mirror glued in at the perfect height up and down, vs stacking left and right.

[planters]

Its becoming clearer...Its becoming more clearer....

So while all this beam expansion talk is in the narrow aspect ie 0.5 to 4mm, the OTHER dimension is 2mm. No one is suggesting 0.5mm to 2mm. for the narrow aspect. Ah Ha!

Have you considered knife edging the two beams at the same height? That, is what I meant by overlap. The two beams would both be at 28mm high offset slightly laterally (the amount of the knife edge gap hence 4mm goes to 4.5mm). I wonder if this would allow a tighter packing at the scanner.

Thanks for all your patience!

[taggalucci]

Can I just clarify some terminology?

I get the general feel from posts I've read that "knife-edging" is used to refer to adding beams to each other horizontally, whereas "stacking" is used when doing the same vertically. I might have misinterpretted this though, so please jump in with your opinions.

[kiyoukan]

I think that is right kinda, you can knife edge vertically but its most often refereed to in the horizontal fashion.
So we could try to clear these terms up for other members, looks like pl might need its own word reference page and usage.