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

[planters]

There is no such thing as a free lunch. ENTROPY RULES!

However, consider for a moment that these diode's emitters are releasing energy at aprox 1MW/cm. Really! And the energy density on our scanners is more like 10W/cm! Aside from the losses due to optical aberrations, we are in no way cheating any physical laws if we reduce the dilution effect of Knife edging. In commercial systems, arrays in diode bars deliver KW/cm because their emitters are more closely spaced not because they are driven harder. Some time ago, kiyoukan was on to something when he considered a positive first cylinder, to allow tighter knife edging at the first focus. Unstable, tricky and complicated? Maybe so, but this may be a significant target to allow more power on smaller and faster scanners.

[kiyoukan]

The idea is a great theory and once i get my 3d printer all ready im going to maybe try to reopen it and design system 100% out of plastic with tons of adjustments for every thing.
It may be possible but even still im not sure on its stability.
It would double the max power as it would let you combine 4 diodes all in a rough 4mm square without the use of a pbs, so if you were to combine with a pbs, 2 setups so a total of 8 diodes that would be a 4w output in a very close to 4mm beam.
But this will need some more testing and i still have all the lenses needed to do the tests.

[planters]

Well, actually that is a good question. Is it worth it? I think so. The rewards could be in the orders of magnitude range.

I had considered wavelength multiplexing to increasing the power density of these multi beams. This also is not magic. It is used in commercial arrays. But talk about complicated and expensive! And the upside is maybe several times at most for at least the doubling of the cost of the module. No go.

But, in the meantime, in addition to the more common beam correction approach, I am also going to go the long down range, single, low power only cylinder ( Edmond order in). This may just prove to be cumbersome and no better, but it might be more forgiving for small adjustments. Also, I built a small adjustment jig that mounts adjacent to a selected flex mount on my 445 module and uses set screws to slide the knife mirror L-R and back and forth (not complicated) and this should work with the G71 set up to minimize parasitic knife edge errors/spread.

[kiyoukan]

Some goods news maybe that we dont even need single diode lens plus the expansion optics.
Im going to with the order add in 2 very tiny tiny c-lenses and see if i cant use 2 c-lenses to get this beam under control.
The price will be higher for these small lenses but they would still cost less than if you had to add a diode less that costs 40$
The idea is to use 2 different c lenses to correct the beam it may work it may not, if it works then you could build crazy combining arrays.

[planters]

Doric Lens talks about this in their lens tutorials. The rub is the extremely small components and the associated tight alignment tolerances involved. To visualize the scale of the issues, imagine if the original collimnator was 1mm instead of 2mm. This would be placed 1/2 the distance to the diode, the slow axis would be 0.25mm wide and be diverging at 20mrad. The beam will reach the 4mm width twice as quickly and be corrected to the same far field divergence as before give or take, but to take advantage of the tighter knife edging opportunity you would have to adjust the mirror with a precision that was smaller than the beam, as is always the case, and so on the order of 100um! The mirror will also have to be ABSOLUTELY orthogonal to the beam stripe and the edge will have to be almost flawless! Oh boy. Oh boy.

Nevertheless, despite these issues I think that this or something like your other approach will work as long as we resist the temptation to say "WOW lets see if we can do this 10 times as much" while our optical capabilities are as yet still so macroscopic and "plywood" based. I think a doubling for starters is a good target while methods to improve/simplify optical alignment and positioning need to be focused on.

[CDBEAM]

Oh Boy….sounds like a mechanical challenge driven by an optical demand!!! Micro translation in the radial and X-Y direction… for a new knife edge mirror mount…all against the backdrop of a DIY perspective!!!. This would be a new path for us. Something like this exists for lens positioning…

http://www.ebay.com/itm/Melles-Griot...item3cc238a62a
But at 229.00 UDS…Yea…Right !!! When pigs fly !!

I am thinking a very small bearing platform, positioned atop some X-Y slider…each vector micro positioned with an off-shore depth micrometer…adapted and permanently mounted to set the position both in the radial and X-Y directions.

Physical size is the Task Master here !!! We have very little room to work in!! Perhaps a less complicated approach then…100 TPI set screws mounted to provide positioning then!!! And finally….we MUST have the ability to lock-down the position once it is established. Just some of my…initial ramblings…..BUT for 2X the power density…..WORTH the mental meanderings!! BEAM

Note: So....if we follow KISS !!! A rectangular plate with a raised perimeter edge. Within that corral...another square plate....positioned from the side members 180 degree to each other....two 100 TPI set screws. That is Layer one. Layer two is the same as layer one...but layer 2 would be attached to the square moving bed of Layer 1....so now we have the abillity to position...and lock.....with some resolution....in the X-Y dirction. Now....we add the very small bearing atop layer 1 and layer 2.....and in some fashion have the radial movement positioned by yet another 100 TPI set screw....with some abillity to lock the radial position once we establish this......Just more blah,blah !! BEAM ( Confounding....ain't it )

[planters]

I do not think it is that complicated.

First, the flex type mounts probably won't work. If a three leg MM1 style mount ( I've made lots and lots of these) were used for the knife, then X translation is taken care of along with tip and tilt and a 0.5mm thread is pretty good (1/10 turn is 50 um).

A small jig set on either side of the diode mount( make a pair and move it around as you line things up) that pushes from each side with similar set screws will take care of the Y, then just a final tightening to lock the mount down. The thermal grease will act as a lubricant.

The mirror, say 10mm square should probably be mounted on a short post away from the bulky adjustment pad to allow it to fit easily into the tight space (to minimize beam spread prior to the knife) between the diode mounts ( I am planning three at 90 180 and 270 degrees with all three beam legs to the cylinders equal). The post should be no longer than necessary to avoid instability and more importantly substantial translation with rotation.
I don't have that neat CAD software that you use to lay this out and so have to do it with words. But, if this is a clear path I'm sure there could be substantial refinements if drawn out better.

[CDBEAM]

MMMM ....I think I see what you are saying......We are traveling down the same path !!! and the guiding principle would be to use that which is already available...and keep things as simple, cost effective and small as possible....like the M1....and really....the tip and tilt of the MM1 satisify the radial needs and also the perpendicularity to the beam axis need. All that is needed is one more degree of movement....the Y.

If I could...I would keep all the movements associated with one " object " like the MM1. I would like to set the LD mount in one location....and have all other components defer to that location. Lotsa ways to skin the cat !!!

The CAD software I have is......rudimentary ( read cheap ) ....I am studying another more sophisticated 3D CAD program.....but teaching yourself....well...takes forever !!! It does help to lay things out in a CAD world.....it also adds time....because one is forever moving the pieces around....to find the perfect arrangment !! Thanx !!Make me a sketch....and I will start to CAD render !! BEAM

Note: You ALL know how I like to ...." Over-Engineer " things !! HAHA

[planters]

kiyoukan,

Been thinking... dangerous! You might want to throw a third positive cylinder into that order. One each in front of the diode collimator and after the knife edging the third could be placed a symmetrical distance on the other side of their mutual focus point to recreate the "nothing happened except the two beams are essentially on top of one another" original beam geometry/divergence. This might make the initial experiments, analysis and adjustment a little more obvious.

If this works... then add another lens ,knife, beam, lens and so on etc etc... Ohhh

CD,

I know what you mean, but sometimes adjustments can get a little crowded. I would keep both options open.

[RGB LASER VERKOOP]

here you go,
9W RGB with 2W 635nm (6 diode's) mitsubishi, with good beam.
(use 2x prism pair and PBS)
enjoy:
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