Maybe it's a combination of moisture as well as power and exposure to oxygen are all possible factors, but sealing it after being opened allows oxygen in, however maybe less moisture, depending upon the relative humidity when you did it, hmmmm....
"there is an increasing number of reported experiments showing that the most important factor contributing to fast (hours), and medium time (hundreds of hours) degradation is the process of carbon deposition. This process involves photochemical reactions leading to the decomposition of hydrocarbons existing in the laser diode environment. "
Yea that is pretty much nothing but an art collage cut and pasted together. Font for the NUBM07E is not the font they use as a standard in every datasheet and it says Engineering Sample which is from when they were still in development before any mass production has been done. Usually they accompany prototype samples to companies for them to start a commitment to make a production.
Keep in mind NUBM07 or whatever is just the part number for the block. The diode part number is not known and it might not mean that every block that says NUBM07 will have the same diodes in them. Might be a diode family or describe the way the diodes are configured like with ball lens or without. Lot of bad info out there. Many times if not most these guys get a source for new diodes but all they have is a part number on the box like NDG4757 or on a block like NUBM05 and that is all they get so they just find a leaked sheet(one reason you see a lot of "Engineering Sample" or "Test Sample" as those are the most likely not to have a binding NDA on) with specs that look to be about right and they mock it up.
Are you testing with only one current. Not sure you have seen but as you turn the multimode dioes up from zero to the max current some lines do go on and off and the picture looks like it might be parked on a perfect current where those lines fade at.
Yes the bars grow as current is increased, I even made a video about it a while back, but this 07 has some strange thin lines that are dim but not dark even at 4.0a, the image with the 2 dark lines was at 2.5a or 3.5a, I can't remember, but they did change with additional current.
I spoke too soon about my de-canned 06 holding up, it pretty much has started to weaken where it's quite noticeable, so I replaced the 06 with a 7A75 I won from Newgazer, I am running it at 4.0a as verified live and running with an inductive ammeter.
This supposed new 7A75 diode is strong and has what I call stage 2 divergence, much like an 05 diode but it also is putting out the 450-455nm brighter blue, I had never read that the 7A75 would do that, I thought they were all 445nm but I don't know because I never bought them when they were plentiful.
Maybe these 7A75 diodes are 05's with GBall removed and a normal window can in place?
I'm reading 450nm typical from the spec sheets, 455nm max, and with an irregular efficiency your diode could well be in the 455 range!
Edit: I'd say when Nich#a design a new diode, do the binning and for example create a bin of 450nm @ 3.5W, then find their client base need different diode forms, eg ball lens or without, then the only thing they change in the lab is just that, it may be the same base/die/bond wires etc, just the lens form changes. :thinking:
Yes, I just saw that on the list of diodes, that's great, this diode is a good burner and the divergence is even better than I thought, I will have to take a measurement.
Yes, it's basically an 05, but with the much needed window can and longevity sparing backfill, I see why people liked these diodes, the NUBM44 is still king, the 44 is what this 7A75 diode is plus some bar length and power, but the energy density per mm of bar/spot is about the same, the 44 just has more bar.
Example the 7A75 at 5 meters makes a 1.25 inch bar through a G2 that's 1 watt per .25 inches of bar/spot
and the 44 makes 7-8 watts over 1.75 - 2.0 inches, so they both do about the same energy density, the 44 just makes more power and divergence.
Interesting theory on carbon deposition on AlInN and GaInN laser diodes. Since these are made by a metal organic vapor depostion, I wonder if the H-C bonds they are blaming might not be introduced during manufacture. It also occurred to me that CO2 might play a role in carbon deposition on the facets.
Yep they really got their nipple in a twist over those or they finally had an actual example of a diode they say is counterfeit they can point to since they deny everything. I get people occasionally that say they called trying to buy direct and N!ch!a said the diodes don't exist like the NUBM44 block. Does not exist. Anyway that diode sucked. I was sent a small sample batch and I called BS on them in 30 seconds and pretty much threw them in the junk bin. I think they were some defective batch someone tossed or maybe they were an early attempt from some china factory to produce a laser diode based on some IP they took. I have never seen a 3 pin 9mm diode from them, had none of the usual markings or characteristics and the output patterns were not right some flickering in two of the ones I tested. I think the dye was mis mounted or something. Still have a few here somewhere. See if I can dig them up.
Here is something to chew on. I have posted about this a few times as I recently got a bit of an educations about the subject and it really opened my eyes to something I should have seen before. Generally the only accurate info from N!ch!a is the part number itself as they are written on the trays. Anyway they say 100% there is no diode witih ta NDB7B77 part number in their catalog. So take that at face value and we would be able to say that part number was typed in by a third party they so take a look at this. The bottom is the special font they use for the part number on every datasheet and both the other seems to have the same font. I always look for those fat bottom 7's. Maybe those were both dome by the same guy.
Put Mitsubishi Laser Diodes instead of just Laser Diodes like the rest of the sheets form their site. The fonts are more tightly spaced. Part number in description actually overruns the next word and then the spacing gets wide. Under Features Pulse is all overlapping itself and there should be tab spacing not single spacing.
They actually edited an older revision datasheet.
I mean come on this is just not paying attention at all.
I find the press release by Nichi@ to be hilarious. They state that they won't be held responsible for damage caused by countertfeit laser diodes. What was the point of saying that? If they want to be so secretive, it is their comeupance that these fake diodes are so easily passed off as the real thing.