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

[GoolGaul]

Steve, I have the utmost respect for you and the knowledge you bring to this forum. Like with chess players, you are a Grandmaster in this field, one of many and you seem very eager to help us learn. However, sometimes you seem to forget that experience is teaching too. $70 is not that much for most of us here. If it were, we are in the wrong hobby. 80% of us probably have spare optics lying around, along with diode mounts, flexmods, TECs, wire, solder, frozen box of Thin Mints that we are hording until the Girl Scouts come around again next year etc etc etc. All I am saying is, this is a pretty cheap experiment. If it can't be done, it can't be done. We will learn why it can't be done. Yes, some of us have to stick our hand in the fire to realize that we will get burned. I really appreciate your concern for our pocketbooks but this is not a $500 635nm C-mount... $70, I will play with this for $70. I may come out with a 500mW red for my lumia. I know you said others have tried this before. Sometimes it takes someone else working it in a way that escaped other people. Let us hold back a night out with the guys, knocking back some brews at the bar and instead spend it on some cheap red. When stuff like this comes up, that is when I have fun. I like trying to figure something out. Steve, again, you rock... but ease up a bit!

wow, that is a much more politically correct way to express the same point my son expressed to me the other day: "Dad, you're the smartest guy I know. you've been thru almost everything, and learned all the lessons...
That means your smart enough to understand that I won't actually care what you think, until I prove some shit to myself."

I am happy to say, a rush to the hospital didn't closely follow that statement. Those could have been some good 'famous last words'

[absolom7691]

Well, I figure with innovation, no matter how futile, can be fun and educational. Not all of us have the optical knowledge that Steve and the others have, but we want to SEE why something won't work. There is that nagging thing in our heads that is telling us "I know this will work... I just know it". Curiosity killed the cat.......... and satisfaction brought him back!

[CDBEAM]

MMM ??? The title sez it all....Lite Fuse and Run !!!...OK...The optics correction was ALL Terrawatts idea...
As Curly would say..." Ima victum a Sorecomestance "

Thanx for the posts....the quest goes on !!! If anyone does have a solution...PLEASE post...I will experiment myself....some.....just for educational reasons....and likely move on to the Opnext 637's

cdbeam and TERRAWATT !!!

[mixedgas]

Dont care about PC. A year ago we were paying 1$ a mW for those diodes in onsies.

At 70$, eh,,,, Go for it.

I personally would save up for the opnext parts.

Steve

[absolom7691]

Not gonna move on to the Opnext diodes, myself... price/mW is not worth it for me. I am going to play with this and see what I can do. I will most likely end up PBSing 2 of these and using a pinhole. I have a 350mW 640nm from Laserwave. If I can get 500mW out of this, then I would be happy. Pinholes after a prism pair actually do wonders. My 445 has a better beam than my Viasho green by using this exact method. dnar was the first to interest me into pinholing http://www.photonlexicon.com/forums/...c-prisms/page2

I'll try this with these Mitsus and see how it looks.

[steve-o]

On the subject of fiber, Karl (Laser Wizardry) wrote:
(from another thread)

if you are old school, try playing with fiber. 400 um fiber works great, fat beam, high losses, but close to TEM 00 out the end.

He may have been referring to a single mode LD for a source, though.

[kiyoukan]

I do agree that on scan mirrors smaller than 5mm these will not be so good on but.
People who have mirrors around 6mm would be able to use these diodes with decent results.
When stacking the beams i think the image in the OP means to stack them one on top of each other not next to.
See image below
beampattern.jpg
I do agree there may be other ways but i think this thread is going to touch on alot unless one way works so well that we stop caring.
Who knows we may be able to get the most power out of these by only using 1 prism on each diode and then combining 2 setups threw a pbs and just cut off the rest of the beam and not even bother trying to fold it.
But for the sake of trial and error i would love to see every way someone can think of tested.

[CDBEAM]

I still have a small amount of hope for these diodes. Experiments will be done, dead ends will be located,
learning will happen....fun with optics....and frustration !! But Absol's point is that the Opnext 637 cost about $ 0.87/mW....and the ML520G71 cost about $ 0.14/mW....( assuming driving the Opnext to 200mW @ $ 175.00 @ and driving the ML520G71 to 500mW @ $ 70.00 @)
My goal is to acheive 2W of 635/637nm after optics for Projector #2. Huge $$$ difference depending on optics loss between the two LD's......ARGHHHHHH !! The injustice !! I will experiment with a 405-G-1 and DrLava Cylinderical lenses....and see what pops outa the other end !! Just a note....the last idea is ALSO from Terrawatt !!! haha

CDBEAM

[LaNeK779]

will experiment with a 405-G-1 and DrLava Cylinderical lenses....and see what pops outa the other end !!

toss the blue lens, use an optima red lens, slightly shorter FL, should work even better with cylinders

[CDBEAM]

OK....But I gotta get the Optima Red....Lets see what the 405-G-1 does....anyone else have the ML520G71 + OptimaRed + Lavas lenses ??? mmmm ??? Gopher it !!!!

CDBEAM