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Thread: NUBM07E 465nm 2.9W Diode Test

  1. #41
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    What is the Aperture beam sizes LS of your setup.? Also the 4x5mm size.... what is the distance thats at.?
    The measurement comes just after the +cylinder. The 5mm is the slow axis. Note: this is just a rough measurement with a scale. It may be a bit smaller when properly measured.

    Extrapolating from your measurement with 3 and 4mm lenses I would say the stock lens is about 6mm FL

    How far away did you have the C-lenses from the diode.?
    Aprox 20mm from the stock lens.

    Interesting results with the Stock lens LS. What are the 2 positive lenses you used if you dont mind me asking. I think i have a few different + lenses here to play with too.. What is the FL of the + lenses you are using.?
    Does the Beam/Dot slightly get deformed with the + lenses.?
    Aprox 100mm Fl. Any like lenses should work. I had these already mounted up for use as spatial filter. The spot can be focused to a perfect line with hardly any artifacts around it.

    The dots can be very easy spatial filtered too and it appears you wont be loosing any/much power at all to clean it up.
    In my set-up the spot is really clean. No need for filtering.

  2. #42
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    The PCX lens that lazerer is using in the picture is +42 and the PCV lens is -7. I did a run of these a while ago and used these for correction on P73 diodes. I sold a few to losquared after i stopped building and selling the RRB modules. I also sold some to Bob. (cdbeam) Funny how things quickly turns into "his" lens..... Its great to see the promising results. But what most people forget is that the blue emitters don,t like air and quickly degrade especially when overdriving

  3. #43
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    But what most people forget is that the blue emitters don,t like air
    This is the reason I opted to leave the factory lens on.

    and quickly degrade especially when overdriving
    Datasheet max is 3.5A. Technically not overdriving at 3.5A.

  4. #44
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    Quote Originally Posted by logsquared View Post
    The measurement comes just after the +cylinder. The 5mm is the slow axis. Note: this is just a rough measurement with a scale. It may be a bit smaller when properly measured.

    Extrapolating from your measurement with 3 and 4mm lenses I would say the stock lens is about 6mm FL



    Aprox 20mm from the stock lens.



    Aprox 100mm Fl. Any like lenses should work. I had these already mounted up for use as spatial filter. The spot can be focused to a perfect line with hardly any artifacts around it.



    In my set-up the spot is really clean. No need for filtering.
    Oh i thought that was Fair Feild. I forgot to write down the Aperture results for my numbers but ill do them again later tonight.

    Ill Messure the FL of the Lens but should be around 6mm as you said.

    Play around with where you place the C-lenses. You might find better results.

    OK Thanks I will look into getting 100mm FL + lenses. I have 50MM Ones to try now.

    Thats because you are using a Longer FL lens. It compresses and or Clips most of the unwanted artifacts in the beam and either puts it in the beam or clips it.

    Using a G lens or a SFL lens you get a + Wing like around the Dot. No power in it though. Very easy to clean up. What iam also talking about is Spatial filtering the 2 extra small lines on the top and bottom of the main beam. I dont think there is Much power in them if any. So you can really clean this up nicely.

    Quote Originally Posted by edison View Post
    The PCX lens that lazeerer is using in the picture is +42 and the PCV lens is -7. I did a run of these a while ago and used these for correction on P73 diodes. I sold a few to losquared after i stopped building and selling the RRB modules. I also sold some to Bob. (cdbeam) Funny how things quickly turns into "his" lens..... Its great to see the promising results. But what most people forget is that the blue emitters don,t like air and quickly degrade especially when overdriving

    Thanks For the Info on the FL.

    Yes I know you are the founder of these Lenses. Bob told me this. Iam Sorry that i worded it in a way that it came off as i was saying it was "His" lenses as in he found them original. What i was trying to say is "His" as in the ones he had and had been using lately. I corrected it to be clear.

    These are Great C-lenses for sure. I have some other C-lenses comming in to try out too but i really like the results on these.

    Where did you get this info about blue diodes.? I disagree on this with today's blue diodes and i think IMO its a Myth. I contacted Nichia about a similar thing "About why they are sealed and are they back filled" and Posted the info on LPF what they said a few weeks ago. While they dint come straight out and tell me what i wanted to hear exactly as a straight forward YES or No the last response i was able to get out of them they said:

    LD is sealed to keep out dust as well as maintain particular atmosphere. The specifics of this are proprietary

    I repeatedly asked them if they are back filled but they would never answer it directly and the best answer i got was that before them stopped answering me and i dint want to keep pushing the same question over and over on them as they where never going to answer it directly.^

    So IMO there is No problem with them being open can and until i can find a practical way to test this or someone can test if they are back filled or they do degrade because of them being exposed Iam going to stick with they are fine.

    I personally think its a Myth and whatever degradation anyone seen was just natural of a diode having a short life then say one that had a full life. No one that i know at least on these forums have tested hundred of open can blue diodes to say that the reason they degraded was because they where open can Vs just naturally some diodes have shorter life then others. Especially since we overdrive the diodes as most people do. Not all people do but most do.

    I don't think we will ever find the answer to this because no one is going to test hundred of diodes decanned at all the same currant under the same condition in a clean room and see what happens.

    Then repeat the same test with canned versions. Maybe a hundred diodes is overboard but id say atleast 20 diodes should be tested to get a Good idea Canned then decanned and see the failure rate. But even 20 sounds low for this.

    None the less if someone is worried about this One can easily seal the diode in a Lab projector module.


    Side Note: Ignore this part but i like to add it when there is an error in my name spelling just incase someone is searching they dont get confused. Lazerer is a Cheap China laser company that made a similar name to mine "Hate that" which is spelled "Lazeerer" I have nothing to do with that company:
    http://laserpointerforums.com/f44/la...com-66273.html

  5. #45
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    See this http://www.osram-os.com/Graphics/XPi...r%20Diodes.pdf on osram blue diodes. Check the section about mounting. It states hermetic seal. Im not sure what decaning will do long term. I just want to play it safe and leave the seal in place if possible.

  6. #46
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    That really doesn't say anything that we dont know. Hermetic seal is Just a Seal that is air tight. IE keep dust and particles out. That applys to any open can laser diode it would be a good idea to seal them. Nichia already answered that. That doesn't mean that if exposed to air it would cause damage because of it. It could be just a common feature. If it was Back Filled with Nitrogen or some other gas then Yes its to protect the diode for an Unknown reason of degradation that would cause damage to the die if exposed but we have yet to get an answer to this if they are back filled. That is the main question. Not if they are Hermetically sealed. Is there anything in the can that prevents the damage... You have to displace the original air if the air itself is what causes the damamge. I dont see them doing this and how they would do it before the weld of the can on. So its probebly cheaper for them to do so and a nice feature to have it sealed.

    These new Desinged diodes are going into a projector or TV Display. Lots of dust flowing around.

    The Can package diode is the most common standard diode to go with. Nichia said its to keep out dust as well as maintain particular atmosphere. They wont answer me if they are back filled to prevent damage in the 5 emails i sent them. Nichia only uses canned diodes from what i can tell.

    The Question still remains if they are back filled to displace the original air with something like Nitrogen to prevent damage to the chip.

    IMO they are sealed because its a Common practice to do so and it helps to keep dust out and air particles out and nothing to do with it would cause diode damage if they dint.

    Since red diodes dont need to be sealed why do they still do it then.? Its just a common practice to seal them , Most all 9mm diodes and 5.6mm out there are sealed cans. If its Red,IR Green blue whatever.. Its just a common case package to be sealed.

    Why does RPMC offer Blue diodes in C-mount or exposed dies.? I asked them Year ago about getting a C-mount blue diode for a special project at that time. Clearly they would not offer it if there was known risk especially a company like them.

    It doesn't mean that if they are opened that damage will begin to take effect and also it doesn't mean that they wont. But as far as an answer i can get from nichia and my searching around its just to keep stuff out.

    Id be the first one to say iam wrong once i get a clear cut answer. But until this is 100% confirmed IMO i believe they do it because its a common practice to and its a standard diode package or the application they are using the diodes in has alot of dust and particles in the air and they are afraid of contamination on the mirror/facets over time.

    At the end of the day its anyone choose to do as they like with the diode. This is why i offer both options.

    I agree its better safe then sorry but the diodes are so cheap now by the time any damage happens we would have went through several revision of better diodes iam guessing. I cant say that for sure but from my own open canned blue diodes which have been more then 10 from as far back as the A130s they are all still going with the A130 having over 2K hours on it... You have a better chance of causing damage to the diode by the way we overdrive them then some unknown seal/gas reason. (For those that overdrive) IMO. Its not like its going to cause damage right away as soon as you open the can.

    Iam not saying that its bad that anyone wants to be cautious to this because there is No answer out there yet but I would love to see some actual data on this subject. Iam willing to do some testing if someone can tell me a more practical way to test it out to confirm this.

    Also I just thought of something. How would they even back fill the diode. There is No fill port on the can. Think about it. How would they put the gas in before the weld machine.

    What it all comes down to is if its Just a Hermetic seal to keep dust out or some special back fill to prevent damage. Ive been trying to another route and have contacted a few other companies then Nichia to get this answer. But i dont think they are going to tell me. I wish we could get a clear cut answer on this.

    Does anyone have any info links of InGaN/GaN material that would show what damages it.?

    I deeply want to know the answer to this.
    Last edited by Lazeerer; 08-21-2015 at 20:32.

  7. #47
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    That really doesn't say anything that we dont know. Hermetic seal is Just a Seal that is air tight
    Right, except it suggests that breaking the seal is bad. I know that is simplistic thinking but that is the best I can do with the knowledge I have.

    It may not have a gas fill. But, it would be easy to control the humidity and cleanliness of the air during packaging. That little die area has such a high electric field it probably attracts water molecules like a vacuum cleaner. I think humidity is what i'm most paranoid about.

    Time will tell. And they are cheap (relative) so even a slow degradation proly isn't a big deal.

  8. #48
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    If its the shipping that is the problem then I agree with you on that until it gets to the end user which then they can seal if they like if they choose the open can module. But once its in the end user hands its pretty common now to seal diodes in an encloser right.? So it should not be a problem.

    Having said that, thats why i ship my Open can module versions sealed in a Anti-static Shielded bag "I use a Impulse sealer" and add a Desiccants and even a Oxygen absorber before the seal. Then I put it in another Anti-static zip bag or i will use a vacuum seal bag then vacuum seal it air tight before shipping. "Wish i took pictures before i shipped them" Ill take pictures of the next one i doo as it might help.

    I do not crack the can off till iam ready to seal/ship.

    I have bought enough diodes/Laser crystals from big well know suppliers to know and see how they package diodes and crystals and learned alot from it. Not to mention all the DPSS lasers i have and work on. Ive learned alot about sealing.

    As for the Chip being a magnet for water. I have LBO Crystals and BBO crystals"which are hygroscopic" from the early 2000's and even some KNBO3 crystals from the mid 90's that are in Mint condition and they where keeped exposed to air in just a membrane case before i got them.

    So time will tell as you say but i IMO we will be waiting a long time.haha.

    None the less i understand what your saying and everyone's worries about it. Hopefully one day we will get a straight answer.

    Until then lets work on beam correction. Very happy with what iam seeing so far.

  9. #49
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    Also I just thought of something. How would they even back fill the diode. There is No fill port on the can. Think about it. How would they put the gas in before the weld machine.
    You can envelop the station in whatever gas environment you want prior to sealing. A crude example is an O2 free hood in a chem lab. But, I agree that if these don't degrade in a couple of hours in open operation then the can is for contamination protection not to house an exotic atmosphere.

    Until then lets work on beam correction.
    Agreed. Time to move on.

    One idea to really nail the aberrations would be to place a plain-parallel window in first the converging and then the diverging beam of a telescope like the one that would be used for the spatial filter. The window will add or subtract spherical aberration from the system. If there is no residual spherical aberration then both positions will increase divergence, but if some positive or negative spherical aberration exists then one position will improve divergence. Adding another or thicker window if this is the case will continue to improve the divergence until the spherical aberration has been countered. Note, the focus in the far field will have to be adjusted ever so slightly with each positioning of the window.

  10. #50
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    Beam correction is fairly straight forward.

    The only questions I have left are; the wavelength of my diode (working on that) and what the throughput of the stock lens is compared to a G lens.

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