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FAKE 150mW Nichia diodes being sold

IgorT

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So, i don't have much time to make a pretty thread and all, but i think this is an urgent matter, as i've just heard these diodes are still being sold, even after i told the seller they are fake weeks ago.



Many months ago i tested a 100mW Nichia diode from Susie (Sandstone). I challenged her to proove IF her diode is real, she cooperated, followed my instructions to the letter and provided me with a sample diode sealed in a tray for my testing.

I posted a thread called "New high power 405nm diode".

I made a comparison PIV plot comparing it to my first GGW 6x diode, and the 100mW Nichia turned out to be the real deal, judging from the PIV data..... It was a great diode with a rounder than usual beam, high efficiency, and apparently very tough. However i got the feeling it is slightly less tough than the GGWs. At that time i believed the GGWs to be a 105mW Sharp diode, but in the meanwhile i found some data indicating that GGWs are more likelly 125mW CW rated diodes, which would explain why i got the feeling they are tougher.

Unfortunatelly i have not been able to do a lifetime test on the 100mW Nichia (= killing it on my cycler circuit) in the past, i only started this now, but that doesn't really matter here.




A few weeks ago, someone notified me of new, even higher power Nichia's being sold at the LSP store (L-E forum's store).


Due to my previous VERY positive experience, i felt as if this was a sure thing. I knew they would come from a tray and have full length pins, so they obviously couldn't be harvested PHRs sold as 150mW+ Blu-Ray diodes, as is often the case on e-bay (PHRs are 40-60mW CW diodes at most!)..


Well, in order to make a more complete test, i decided to buy two of them, since one could be a random freak or a random weakling. I know from experience how much 405nm diodes vary from one to another. I have collected partial efficiency data on ~100 PHR diodes and full PIV data on over 56 GGW diodes so far (the fun part will be typing the GGW data in, but it will make a great statistical sample, when i'm done).



Anyway, the two diodes were shipped to me in the incorrect way, and since i feared it would take them a month to arrive i ordered a third with USPS Express.

The total cost of this experiment came to around $200... I would have been fine with that. If only the diodes were at least as good as the 100mW Nichia's... :cryyy:



After receiving them, i only tested two.... I left the third untouched, because by then it was clear to me that they are anything but 150mW. They are not even close to 100mW. :undecided:


Here are the two PIV plots i made. The so called "150mW Nichia" diodes are clearly no better than PHRs, or maybe 4x's at best, as is evident from the kinks, and from one of them dying during quick plotting at 250mA! Within the kinks their spots would also deform as they do with PHRs or 4x's..



The real 100mW Nichia showed no kinks at any power it could possibly be expected to survive for any length of time, a characteristic shared by GGWs. In 56 GGWs i tested so far i only found ONE showing anything resembling a kink.



So what have i learned from this? Well, other than the diodes clearly being complete FAKEs (they MAY be Nichia's, but they can not possibly be rated for more than 60mW), that in the future i should approach such tests with a little less optimism. :undecided:



Again, sorry for the rushed thread, but after someone mentioned them to me today, believing they are real, i realized i should have posted this much sooner. So far i only mentioned the resulst in another thread of mine, but i think everyone should know this, so they don't throw away money like i did.



P.S. I am also attaching the old GGW vs. 100mW Nichia comparison PIV plot i made, so you don't have to look for an old thread just to see the difference. The main difference is, that the power goes straight up, increasing linearly with current on both the real 100mW Nichia and the GGW.


The plots were all made on my "Diode Analyzer TM" (last attachment), a device i made specifically for this purpose. I use it to test every diode before putting it into a laser, and i hope soon to be able to post the collected GGW data as well....


EDIT: Oh, and all powers here were after AixiZ acrylics. I replotted one of them with a short FL glass lens, but by then i was too depressed to bother typing the data in.



EDIT 2: Forgot to include the SpecSheet of the 150mW Nichia...
 

Attachments

  • 150MW NICHIA 1 - LR.JPG
    150MW NICHIA 1 - LR.JPG
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  • 150MW NICHIA 2 - LR.JPG
    150MW NICHIA 2 - LR.JPG
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  • 6x vs Nichia PIV Plot - LR.JPG
    6x vs Nichia PIV Plot - LR.JPG
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  • OmniDrive-Diode Analyzer - LR.JPG
    OmniDrive-Diode Analyzer - LR.JPG
    527.3 KB · Views: 389
  • 150mW Nichia SpecSheet.jpg
    150mW Nichia SpecSheet.jpg
    77.8 KB · Views: 872
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IgorT

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Oh, i gave the seller the horrible test results a couple of weeks ago. From what i can tell, he was clearly screwed by some unscrupulous Chinese suppliers, and didn't expect the diodes to be bad.

I just noticed a new reply from him, we'll see how the story unfolds.

I definitelly feel very bad for spending $200 on three "PHRs" with full length pins. :(
 
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Ouch, maybe they'll work something out with you?

I prefer not doing business with laser surplus when possible, but they seem like an honest business.
 

IgorT

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Well, if those diodes were real, they would be a great next higher power step from GGWs. That's why i jumped on them. That and the fact that the Chinese are scaring me about the GGWs not being available any longer.. I also expected a better beam aspect ratio (= rounder), from my previous experience with Nichia's.

But now i really don't know what to think. Clearly someone in China has access to fresh diodes from trays. If only they were not scammers they might be able to get us the real deal.

But it's possible they tried these diodes, pushed them to 150mW (just like we did with PHRs) and falselly believed they can take it (just like we did with PHRs), and sold them as 150mW. In fact, these diodes could be the exact same model as PHRs. A very depressing thought after spending $200 on three.


Another thing that made me think it's a sure thing was the datasheet. It was nearly identical to the one from Susie (Sandstone) of the 100mW Nichia, only showing specs matching a higher power diode...


I don't know what to think right now. I would love to be able to buy REAL 150mW Nichia's, they would make GGWs "obsolete", especially at the same price... I wouldn't mind buying from LSP, especially since they could apparently provide them one by one without any supply limits, while the Chinese keep crying the GGWs are dissapearing, which is making me worried.


I don't believe it was Steve's fault, but i do think he should do something about it. And obviously stop selling the diodes....

We'll see..
 
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Thanks Igor, its nice to know that you, at least, have stuck around to help us consoment noObs not to piss money away in a fashion that resemble idiocy.
 

jayrob

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Thanks for all you do Igor...

... and for sharing the results of your testing. I hope he compensates you in some way. Let us know how it turns out.
Jay
 
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Thank you for your data and work. I will be saving it to compare to future diodes.

-Kendall
 
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Igor;

Like you, I studied the data sheet, and thought they would be very good diodes.

I even figured the max peak power: 280 mw @ 258ma.

Now, to find out they are not really the Nichia item.

Very discouraging. What do these vendors think ???

LarryDFW
 
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Thanks so much Igor! I was hoping the Nichia 150mw would be our next great deal in 405nm, but as you say, at least in the near term there could be a shortage of good high power blu-ray sleds/diodes. At least for the ones that don't cost an arm and a leg. Thanks again
 

IgorT

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Yea, i said so in my Blu-Ray sales thread, it is my belief, that the REAL 150mW Nichia's that actually belong to that datasheet, would be exactly as powerful and tough as the 8x's are, or at least VERY close....

That's the reason i was so excited! I mean, i wouldn't push them to more than 300mW after plastic lens, but nor would i do that to an 8x.... We know that 405nm's can survive being pushed above and beyond even their pulsed ratings but their life gets dramatically shortened.

But i'd love to have a reliable 300mW+ diode at affordable prices! Especially since the power with glass would go near 400mW....



But this is just sad... Save your money and buy PHRs instead. At least you won't cry when they die.. PHRs are not too tough, but at least they are cheap and easily replaced. This... I don't even have words for... :cryyy:


I made a comparison plot (attached) of the two "150"mW Nichia's and the real 100mW and a GGW (i called the GGW a "125mW Sharp", altho the make is a guess and the power an estimate). I made this combined plot with explanations, to help Steve explain to the Chinese why we know the diodes are "fake" without a doubt. They might be from Nichia, altho i've seen diodes of a power lower than PHRs but with a rounder beam, similar to the real 100mW Nichia, so maybe the aspect ratio is also an indicator of not even the manufacturer being real... But it's hard to say anything like that for sure from simple observations.. The "fake" Nichia's had a flat beam resembling the PHRs very closelly.


Anyway, the kink position is a very good indicator of diode power. If you test a large batch of diodes and they have kinks as low as 100mW, they are not likelly to be rated higher than 50mW, possibly even less. A diode has to be kink free to it's rated pulsed power, in order to be useful for writing in a drive. Otherwise the drive could not possibly reliably pulse it to a certain power, not to mention the spot would get distorted (TEM issues - the spot starts splitting into two) inside a kink... Of course, when i talk about power, i mean raw power of a diode not power after any lens, but i considered the losses in my estimates.

So that, and the fact that 100mW Nichia's and GGWs are kink-free as high as i dare go during testing are proof enough for me. Only someone, who doesn't have a clue about diodes would sell these (or PHRs) as anything more than 60mW CW diodes.



P.S. Oh, and i forgot to include the spec sheet of the so called 150mW Nichia's, i added it to the first post now. It's what made me buy them, since it was just as convincing as that of the 100mW model which turned out to be real...
 

Attachments

  • Fake vs. Real diode Comparison Plot with Explanations - LR.JPG
    Fake vs. Real diode Comparison Plot with Explanations - LR.JPG
    416.6 KB · Views: 475
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jayrob

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Nice comparison graph!

That's one to copy and save in my documents...

Thanks Igor!
Jay
 
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Hey Guys...

To all the members here that bought these Nichia LD from that "other" store....
I just saw this Post by the Seller...

I have pulled the sales of the 150mw BluRay diodes due to several reasons.
Today I found a post on the LPF by IgorT.

FAKE 150mW Nichia diodes being sold

I did get test results from IgorT, but wasn't totally sold on his results due to NO customer complaints on them what so ever!

The only customer to complain did so due to the post at the LPF, he didn't come right out and state that fact until I asked him what made him think the diodes where underpowered, ONLY THEN did I get a straight answer of he did no testing but read the post above!

That to isn't proof of shit, had he hooked up a diode and had it fail prematurely then I would be more likely to believe that thee diodes are not what they where sold to me as.

I have been in constant contact with the supplier:

Quote:
Tracy
IT-sources International Ltd.
www.it-sourceshk.com
www.itsources.en.alibaba.com
MSN:tracywang23@live.cn
Tel: 086-755-82392839
Rm. 1204 Great China Tower Building no. 1008 JianShe Rd. Shenzhen, Guangdong, China Tel: 86-13728791130
Chinese address: 中国广东省深圳市罗湖区建设路1008号大中华汇展阁1204王春霞(收)
Even after sending her IgorT's test results, I have not gotten any refund, any diodes of the proper power or ANY compensation of ANY sort!

So I'm am out a HUGE amount of money on this one.


If anyone has purchased these diodes and found them underpowered, Please post here, PM me and/or email me with your order number so I can take care of you.

I do want some details as to HOW you found them under powered. I'm still not 100% sold that these are not the power I was told. because of the lack of complaints.

As we all know, People will complain very quickly when they feel they didn't get what they paid for.


I do not knowingly sell anything in my Store that isn't what it states it is, and I will make it right with the customers involved.

Will someone PLEASE post this in that thread!


Thanks
Steve


Just thought I'd share... it seem he was not aware of any problems and wants to
make it right...


Jerry
 
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daguin

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Just thought I'd share... it seem he was not aware of any problems and wants to
make it right...
Jerry

That being said, if your diode is installed and it is running the way you want it to, don't demand a refund. If it is working for you in your installation, then you should hold onto it and enjoy it.

Ask yourself this question, "If I didn't ever read this or hear about this, would I still be happy with the diode?" If the answer is "Yes", then you do not need a refund.

It look like Steve is going to take it in the shorts on this one. Don't compound the problem just because you can.

Things like this are part of being a member of a community of "experimenters."

Peace,
dave
 
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I agree completely.... just because he wants to make it right... is no reason to
take advantage of this gesture...
unless you really/honestly are not satisfied with your LD...

BTW...this Thread should not be the deciding factor if you are happy with your LD..

Jerry
 
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Dear Steve

Sorry to made you so many problems for the last sample shipment. Since our supplier (they supply those diodes to many factories in China) have some personal problem that we can not contract them in the last two weeks so we can not find out the problem on time. We send you a mail this Monday and ask you to send me black two unites with your own marking that we can bring it to our supplier for a detail testing and find out the problem and solution. Their have some high power diodes coming within this week with original packing from Korea (this diodes is made in Korea but not China). We can take a photo with original packing before pick up two unites to you for re-testing if you want. We are not direct manufactory that we can not made sure 100% without any problem. We only can do is to check the label with original or not as same as the CPU and memory which the marketing doing. The problem is come from the manufactory if the goods with original label packing but still have those problems. Pls. send me black two pcs if you want find out the problem and solve it.

Thanks
Michael
 
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Wait does this mean possibly these knockoff didoes could be showing up in lasers from yagoo, viasho, and CNI? Some high grade blu ray diodes would be pretty cool.

Sorry about your problem and I hope you get it resolved, must be cool to have a LPM
 




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