ML501P73-2, a capless 638nm 5.6mm 500mW Red Laser Diode - Test results.

[MIIKKKLLLL]

Maybe... you play with the wavelength of half of the diodes, and then you put a dichroic filter??
Like 6 diodes under 0°C and 6 diodes at 25°C, this could creat a shift of about 5-6nm. Now I don't know if such a steep filter (cut at 635nm) exists...

Anyway, this is a very interesting project.

[planters]

I am not going to speculate anymore just based on this limited information. And, you should describe your technique or patent it, but if you are able to get that kind of performance and will eventually show the "little beast" then it will become clear at that time anyway.

I was very frustrated with the last go around with the mystery lens and so I would wait this one out.

Maybe... you play with the wavelength of half of the diodes, and then you put a dichroic filter??

I tried this last year. The best filter was a holographic notch filter. The filter can be tuned with a little tipping, but is very expensive. Also the Mitsu diodes do not temperature tune as substantially as the LOC diodes (which I tested) and so to prevent each group from drifting into the cut off wavelength during modulation loading and limiting the temperature deferential to 40C ( you loose a lot of power with the "hot" one) I think you will be limited to combining 2 groups. But... this does work.

[CDBEAM]

Time will tell....I have a few ideas....ALL untested....about novel optics combining !!! Enjoy the " Cheese Cake " pic !!
BEAM OUT

Note: Hope your health is improving...Working with Coherent Light is a proven therapy !! mmmm so's Cheese Cake !!!

[steve-o]

Man .. that is one nice pic CDB .. I can't take my eyes off her "slip-knot" ..

[steve-o]

If you very slightly rotate the second (positive) cylinder in the plane normal to the beam the central spot returns to a clean rectangle, BECOMES SMALLER and the most noticeable effect is the appearance of crisp distinct multimode stripes stacked vertically above and below the central spot. The stripes can be easily removed later.

Wow! Great advice! With a little work the far field dimension at the exact same distance went from 45mm to 28mm now resulting in a .93mRad divergence. And thanks Andy too, the diode did need a bit of a rotational correction. Cool beans you-all ! And still at way above 600mW per diode this P73 project is really shaping up



The multimode stripes:

[planters]

Now the fun starts. With a better beam you have to achieve better diode co-alignment to continue to see this performance. Then a final pass thru a spatial filter. You are at a level of beam quality that will exceed an unmodified DPSS. So... now you will want to look at a low power beam expansion telescope for the green!

[borgqueenx]

Less then 1mrad! Thats awesome!
If this topic continues you guys soon reach a 1x1mm beam and a 0.01mrad!:P

[andyf97]

Less then 1mrad! Thats awesome!
If this topic continues you guys soon reach a 1x1mm beam and a 0.01mrad!:P

Impossible but sounds just like the kind of challenges I like.

[borgqueenx]

im giving laseevr advice on a module they make.
What lenses do they need to make/buy or other stuff to make a dual and quad build have less mrad and a small beam size?

[badger1666]

Hey steve sorry to piss on your mrad calc , but i think you measured it on the width for your calc should of used the height
(2mm proberly nearer 1.5mm) as thats the bigger expanding axis which would make it 1.10 mrad on the fast axis
Which is exactly the same as i am getting , big thanks to planters for the lens rotation info now my beam looks exactly the same as yours steve.