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

[andyf97]

I just love dr planters videos, they are very interesting to watch.

I too did a bit of something related that might be of interest with a G71 in 2011. I did this test to simply see at what temp the power is most steady, I did not record the current because I was only interested in finding a stable temperature vs power which turned out to be 25c 750mW. I am going to do the same for the P73 tonight which should exceed 1W at least for a moment.

[steve-o]

Great vid Planters! Thoroughly enjoyable, Thanks for that! I am confused though, at the beginning you said it was a mitsu G71 and at the end you said it's a P71.. is the laser diode the 300 or the 500 mw diode? Maybe we should just call them the mitsu 300 or 500mw instead of G71 and P73 .. it gets confusing .. :]
Nice work too Andy, all good data, thank you both .
I might try chilling if I could design a simple bulletproof circuit using only one NTC and one TEC
I'll have to get on that ..
Thanx y'all

[planters]

To be completely clear, this was the Mitsu 300 mW diode. This was the small one not the more powerful P73.

I also just posed the results of chilling the M140 445nm diode in a thread on Optima lenses for reds. I know, but this turned out to be a very good lens for 445 as well and one thing followed another and... Anyway. the power increases from RT to -16C by 11%, not nearly as good, but interesting.

[swamidog]

mr. planters,

you have a beautiful workspace and you're doing a really excellent job taking data with your research. thank you for supplementing our speculation with good science.

I finished the video and the link is below. Just a note; even though I say this once in the presentation be aware that all the power output readings are 10% lower than the actual output due to the losses through the microscope slide.

[CDBEAM]

Thank you Mr.P....You light the way !!! Mr.BEAM

[kecked]

now that was worth watching. I'd love to see a whole set of tutorials for people just starting out on how to build and wire projectors.

[steve-o]

Yeah, especially since I still don't know how to wire up my LIDA port

[planters]

I strongly agree. These videos are not difficult to do if you know the material well. I know this material well, but there are numerous areas where I struggle and if anyone (you'll know who you are) who has some insights or tips will spend the time to produce a video, I think this will jump start a lot of projects. It could save time and money, not to mention improve safety.

I wouldn't limit it to subjects just for the novice either. Make it interesting for every level.

[Stoney3K]

Maybe I'm crazy here, but what are the chances of driving these bulletproof diodes (445 Nichia and Mitsu P73) with regular off-the-shelf LED drivers that have constant current output?

Given that every protection mechanism is pretty much built into these puppies, maybe we could stop trying to reinvent the wheel.

[planters]

I don't think your crazy, but the drivers now available that come to mind ie the FM P3 and Badpip's dual and quad, all work very well, are modulate-able and are relatively inexpensive. The P3's are sometimes hard to get, but the others are easy and my list might not even be exhaustive. So...there doesn't seem to be a need to waste any time on any reinvention.

I have a new area that might be addressed, however and that is spatial filtering. The blue's suffer somewhat from far field noise, but the G71 and probably the P73 as well have a lot of down range artifact such as wings and multi-mode patterning. My initial rough attempts to filter this have been successful and I'll bet if I aggressively dial this in then this could be very impressive. 4W of single point red in a dark field....

The issues are:
1) The focusing and recombination lenses and the trade off with FL. I BELIEVE a microscope objective will be too demanding on positioning and alignment.
2) Masking a very small and probably irregularly shaped focus
3) Aligning the mask
4) Filtering each diode (Argggg) or the array
5) Survival of the mask at high power levels
6) A compact and easily fabricated mask/lens assembly.

I am no where near the video phase, but I am thinking a lot about this. Any ideas?