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Thread: What diodes are these?

  1. #1
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    Default What diodes are these?

    http://cgi.ebay.com/658nm-RED-DELUXE...QQcmdZViewItem

    If anyone could tell me from the specs what type of diode this is it would be really appreciated!

    Or if someone could point me towards a source of similar diodes it would be really appreciated! I'm going to need about 30 (~100-180mw) diodes for the project I am working on!

    Anyone know of any Chinese manufacturers or someone that sells in bulk? Anyone looking for a group buy of 658nm diodes?

    Ok, too many questions Thanks everyone!

    -Max

  2. #2
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    I bought a couple of those. I am not sure if they are really as powerful as they say. I am running one at 150mw right now and it seems OK.

    Aixiz sells 200mw CW (350mw peak) diodes for $40 on their website. They supplied me with the data sheet so I know that these are really 200mw diodes. I ordered one.

  3. #3
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    Looks iffy, no make or part number stated in the listing. Gary, what markings, stamped or printed, are there, if any? Also, if you find out what lifetime you get at 150 mW CW, can you post again to say what you found?

    The Aixis diodes sound interesting. Price per milliwatt is still no better than a Rohm diode at £12 each. Still nice though, if they'll do 200 mW for a long time. Bet they won't though:

    "Note1: The maximum rating means the limitation over which the laser should not be operated even instant time. This does not mean the guarantee of its lifetime. As for the reliability, please refer to the reliability report issued by Quality Assurance Section, HF & Optical Semiconductor Division, Mitsubishi Electric Corporation."

    You might do ok at 160 mW though. Would be useful to see Mitsubishi's MTTF data for those. As that 200 mW CW is an absolute max rating, it's likely that the headroom is SMALL beyond that, if any. Even a Rohm diode will do well over 225 for a few days. That's obviously true because that's what you get AFTER an uncoated simple acrylic aspheric lens, so the diode must be doing even more.

    So these diodes are not that much further ahead. And look at the disclaimer's odd word order and syntax. Same as in that eBay listing. Looks like that seller just went to Aixiz (or other route out of Mitsubishi) and figured that adding a few cheap antistatic and lab disposables was a neat way to sell diodes. He's still selling cheaper than Aixiz though, two at a time, but I guess he bought bulk.


    Edit: Uploaded copy of PDF I quoted from...

  4. #4
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    Here is the thread where I talked about the diodes from ebay:
    http://www.photonlexicon.com/forums/...ead.php?t=3212

    In regards to the Aixiz diode, it will be interesting to see how long it lasts. Andy says the 130mw CW mitsu laser diodes he has have been OK at 200mw and these seem like the next gen of those. Specs look all the same except higher power. So, I have no reason to doubt them. But I agree with what you said and may limit it to 180mw or so. That should be enough for me.

  5. #5
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    Cool, I forgot that thread. Saw it, but there's so many on diodes. I have a personal interest so I try to keep up with them but there are LOADS. My guess is those diodes might be the same, coded differently by the maker after establishing reasons to justify uprating the claim for them. They'll all come from a continuous process of attempted improvment anyway. Similar thing was done by Opnext. Some of the 50 mW's were just like the 80's, just not all as capable of decent life at 80, so I think they started calling them 80's when they refined their production to the point where failure rates fell to the point where they could validly claim that.

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    I also bought one of the kits from the guy. This way I have a little bit of experience with diodes and have some of the proper equipment before I step up to some more expensive diodes. I thought they seemed under 150mw as well but I haven't purchased a meter to be sure yet.

    Where do you guys usually buy your diodes from? Do you have any around the specs I am looking for? I have rigged up my drill press so I can press diodes into the Aixiz housings (12x30mm). As I am planning on doing it with a few of the 405nm diodes coming my way, and hopefully a few higher power 658nm diodes!

    Right now I am just forcing myself to learn! It's the fastest way that I can learn - Just Do It. Nike style.

  7. #7
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    Got mine on eBay.
    Big post about that here:
    http://www.photonlexicon.com/forums/...3771#post33771

    Goes into depth about pros and cons of DVD diodes too.

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    Thanks Doc! I've been looking at the ones on ebay, just wasn't sure what to get, and I always think there has got to be a cheaper way to get them. Hence the question about the group buy in the first post ... anyone?

    EDIT: Doc do you have a link to an auction you have up?

  9. #9
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    Thought you'd never ask!
    Seriously though, I haven't been pushing, I just told it like it is and let a few buyers decide. The current state of things is described in the listing I'm running at the moment, here:
    http://cgi.ebay.co.uk/ws/eBayISAPI.d...MESE:IT&ih=005
    Price to start is low, half what several people have already paid. Since I wrote that bit about full price bids, another one went with Buy It Now at £60, last week.
    This is the first time I've mentioned them here, I set a deliberate policy of waiting till someone asked.

  10. #10
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    I am glad to be the first person to ask. I kept looking through all the posts that were talked about them and couldn't find a link anywhere!

    But I forgot you were on the other side of the pond... sometime in the next few weeks or so would you be willing to do a sale through PL? I could just send the payment via paypal or google checkout, that way you wouldn't have to deal with eBay fees. PM me if you are interested and let me know how much you would want for 1 diode and we'll go from there.

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