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

[andyf97]

Taggalucci, i have a simple question for your points.

If you take 8 opnext diodes and knife edge them together into a 4x4 grid & I take 2 Mitsu diodes and combine them together into a single 4mmx4mm beam using a pbs and correction with the same divergence as the opnext combined beams, which has the most power density within 5mm x 5mm space at 10 meters.

I know the answer because I used opnext for years and ML this week. This new ML eats the Opnext just like the harvested 445s did to DPSS. Oh then lets take the power up a bit using the P73 which has almost same specs as the G71.

You have to get use to the idea this new diode is going to have similar implications as the blue did. [Edited in] Don't take my word for it, do your own tests like I did.

Andy

[steve-o]

..my problem is i have a hard enough time aligning more than 2 diodes I have seen others do 4,6,8,12 and I have seen the famous arctos photo of 42,000 red diodes in 1 projector , arrrgh . Beam quality is important . Power density is too. Simplicity and cost (esp in these times) is equally important. imho . I would love to see 2 500 mW diodes in shape. But, it seems everybody yanked the mitsu 500 mw off the market at the same time. Seems that there may be a quality issue ? ..

[CDBEAM]

Andy, I gotta jump in here…I started this thread …252 posts ago…There is great interest in this diode…as you would expect. IF this LD can truly be tamed….and made more or less equal to the 445 LD….I am a great supporter….I WANT THIS DIODE TO BE WHAT WE ALL WANT…..BUT…while that is what I want….That’s great…..but until others can duplicate your results….I remain …restrained in being convinced that we have a solution at hand.

While the vast majority of us are NOT scientists….we must still subscribe to Scientific Methodology. Science speaks in numbers, measurements and full descriptions. Science demands verifiable repeatability. Typically… observation follows theory.

Please take this post in the spirit in which it is offered…I completely support your efforts and am hopeful that you have indeed found an Aspherical Collimination lens which …in combination with cylindrical lenses… that corrects the ML520G71 output….BUT…

You challenge us to “ See for ourselves “….so we can verify your results. Well…how can we do that…until we know exactly which lens you used. Yes…I understand that this information is not yet available. I would hope that a way can soon be found to identify the “little lens “. But until I see posts which repeat your experimental set up…I remain VERY guarded…Hopeful….but not convinced.

Again…I ask….what is your beam geometry just after aperture….AND what is your beam geometry at 38M….or whatever distance you choose for a farfield beam termination. This is data which quantifies your results and is necessary for me to evaluate your results.

I have spent a fair amount of time in my experimental set up…..and this investment demonstrates my hope and commitment that the ML520G71 or the ML501P73 can be made usable. I guess I will add is that …just because this is what I want to happen….does NOT make it so !!

Attached are a few more pics showing my set up….modified to show the internals of the Lava Cylindrical Lens holder.

In closing…I am also hopeful that this thread can return to a cooperative civil tone. A framework of shared problem solving and support should rule…. and not regress into an adversarial exchange of Bull Shit.

CDBEAM

Added: Yes...mW/cm2 power density is yet another parameter to consider !!! Never an easy answer !!!

[steve-o]

..and .. not to throw this thread off- topic but i just had some fun with my "better-than-nothing" approach (far-field measurements not done yet 'cause ive worked all week and its 11:30 and i'm tired but here tiz:

[dave]

It goes against the laws of physics.

hehe

[CDBEAM]

Yikes !!!!!!!!!!

[andyf97]

..and .. not to throw this thread off- topic but i just had some fun with my "better-than-nothing" approach (far-field measurements not done yet 'cause ive worked all week and its 11:30 and i'm tired but here tiz:

Steve, if you want to use prisms you will have a fat beam, if your happy with a fat beam use two not just one and then you will have a rounder fat beam. There are posts some place in the forum for placing prisms and am sure somebody could drop into this thread one sketch of how to place them.

[andyf97]

Andy, I gotta jump in here…I started this thread …252 posts ago…There is great interest in this diode…as you would expect. IF this LD can truly be tamed….and made more or less equal to the 445 LD….I am a great supporter….I WANT THIS DIODE TO BE WHAT WE ALL WANT…..BUT…while that is what I want….That’s great…..but until others can duplicate your results….I remain …restrained in being convinced that we have a solution at hand.

While the vast majority of us are NOT scientists….we must still subscribe to Scientific Methodology. Science speaks in numbers, measurements and full descriptions. Science demands verifiable repeatability. Typically… observation follows theory.

Please take this post in the spirit in which it is offered…I completely support your efforts and am hopeful that you have indeed found an Aspherical Collimination lens which …in combination with cylindrical lenses… that corrects the ML520G71 output….BUT…

You challenge us to “ See for ourselves “….so we can verify your results. Well…how can we do that…until we know exactly which lens you used. Yes…I understand that this information is not yet available. I would hope that a way can soon be found to identify the “little lens “. But until I see posts which repeat your experimental set up…I remain VERY guarded…Hopeful….but not convinced.

Again…I ask….what is your beam geometry just after aperture….AND what is your beam geometry at 38M….or whatever distance you choose for a farfield beam termination. This is data which quantifies your results and is necessary for me to evaluate your results.

I have spent a fair amount of time in my experimental set up…..and this investment demonstrates my hope and commitment that the ML520G71 or the ML501P73 can be made usable. I guess I will add is that …just because this is what I want to happen….does NOT make it so !!

Attached are a few more pics showing my set up….modified to show the internals of the Lava Cylindrical Lens holder.

In closing…I am also hopeful that this thread can return to a cooperative civil tone. A framework of shared problem solving and support should rule…. and not regress into an adversarial exchange of Bull Shit.

CDBEAM

Added: Yes...mW/cm2 power density is yet another parameter to consider !!! Never an easy answer !!!

Your setup there is cool but place the mirrors the right way round. The concave needs to be reversed. Look in my post #207 picture 1. the photo is not so clear but you should just make out the orientations. or at least it does with the little mystery lens.

Best Regards

[andyf97]

for CDBEAM

Attachment 28080

And which collimator are you using there?

By the way, with my lens I don't try to get the beam good from the start, just small. its just used to narrow it. the DRlava correction will do quite a good job after depending on what lens you are using. But still this little dam lens is making the most significant difference. No clipping and I am sure if its coated good will be little losses.

Spoke to a lens supplier on Friday about ordering some little lenses to establish which one it is and also some variants similar to see if I can get the beam even smaller to aid knife edging.




I am already planning a 2 diode build.

[andyf97]

A little plan for you guys to ponder over.

Attachment 28081