Terrible beam off of Oclaro 638nm 700mW diode with new G2 lens

[Alaskan]

The rectangle shape of the beam from that diode doesn't bother me, its how much the beam diverges in a fairly short distance that disappoints me. However, I have 8X expanded the output from a 700 mw output 638nm multimode diode and tamed the divergence enough to be happy with it. Becomes a fat beam of course, but instead of a wide rake of light into the distance will stay a rectangle shaped beam, once it goes far enough you can't see the shape anyway. I like doing night time beam shots, so that is what I needed.

http://www.ebay.com/itm/Linos-Laser-Beam-Expander-2-8X-630-830nm-/272028086291

 

[Planck662607004x1042m2kgs]

there's a member called CDBeam.. and he corrected and pbs diodes on his build. May be contact him as he could offer valuable input on this subject.

 

[Lifetime17]

Hi Paul.
It's an improvement over all and a difference in the dot.
@ Accu,
There is clipping try it you will see for your self , there is a difference.

Rich

 

[CDBEAM777]

Yes...See my link below..." Dragon's Head " All doable !!!

Unfortunately...The Oclarro 63193 and the Mit P73...both multimode Red... remain the most powerful LD available...and both need optics to tame them...So what !! A few extra $$ for the optics...That is what is demanded.

There have been many, many threads on how to position the lenses in front of the LD...positioning ideas..from easy/ basic...to special/machined !

So far....all our LD's are able to be corrected...63193, NDG7475 and the NUBM series

Search the site...learn your options...enjoy your trip.

CDBEAM

 

[Alaskan]

I have to say, red is so cherry! i love the color of a red beam in the night sky, just that I can't get the beam characteristics I want from one, neither super high power and great divergence from a single diode. Although, with beam expansion the divergence problem is solved, I'd love to PBS cube combine two over driven 700 mw 638 nm diodes though, that would get me most of the way there. Knife edging could be interesting too, maybe the solution I need.

Edit: I'd happily take a red wavelength version of the NUBM44 and expand that, or green, but wouldn't we all

 

[paul1598419]

I've seen the cylindrical lenses made to correct the divergence of the Oclaro or the Mitsubishi 635nm multimode doides. You can find them all over the web, especially on eBay. I have still not seen a build that incorporated them all and seen the resultant beam. The idea from PL on DTR's post to me is the most complex I've seen so far. I would love to see this done and see what the results would look like and the beam specs with the new output power. So far, I haven't actually seen it done yet. The diodes are very cheap these days and I have a couple in my stock just for $hits and grins. I do have cylindrical lens pairs, like the 6X from the last group buy, but I was saving them for a 44 build. Have never pulled the trigger on a pair made to correct the 635nm though.