GGW-H20L 6x Sled GB!!! THE EPIC GB THREAD LAWL!!!

[jayrob]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Igor, I get 'corrupt file' on that link for the data sheet...


sk8, how did your overnight test go?
Jay

Edit: Oh... I see. We must have been typing at the same time.

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

please attach data sheet

I had problems with the format.. It's attached now. I had to rename the extension to .ZIP for the forum to accept it, altho it is really .RAR, but i think most extraction programs won't get confused...


Did you do the test, btw?


EDIT: If your extraction proggy gets confused, rename the extension from .ZIP to .RAR, or use WinRAR to open it.

 

[daguin]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

It this turns out to be the Sharp diode you mentioned, then we don't have to harvest the sleds anymore! We can just buy the diode from DigiKey!
http://www.digikey.com/scripts/US/DKSUS.dll?Detail?name=425-2697-ND
Hmmm..... I guess it's a little pricey from them though! ;D
[highlight]$1125 bucks! I wonder how many of them they sell[/highlight]...
Jay

Apparently they sell enough to justify keeping the page active and updated. Researchers need a "clean" diode. They have to spend their grant money somewhere or risk loosing it and having subsequent requests reduced.

Peace,
dave

 

[jayrob]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Igor, can you save the Data sheet as a .jpg? Or, do you know if WinRAR is a free program? Because the only link I found for it wants $.
Jay

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

It this turns out to be the Sharp diode you mentioned, then we don't have to harvest the sleds anymore! We can just buy the diode from DigiKey!

Hehe, yeah, i know about that. I think that's where the datasheet is from. But we will never know for sure, as no one will buy it from DigiKey.. At least none of us..

But i do think it's the closest matching candidate so far! The GGW has too low a Vf, the PHR is a little closer in Vf, but can not possibly be rated for 105mW.

I think the GGW is rated at least a bit higher, than 105mW. I know of a 120mW Sony 405nm diode, but it has no datasheet, so...


If it's the same diode, it is definitelly much better, than the PHR. But as a 4x writer, it better be!

 

[jayrob]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Here we go...

I found a direct .pdf link that works:

http://document.sharpsma.com/Handle...ments&fileid=5908EFD87FDB4F6782EE3B2F00523CE4

That would be cool if you could identify this diode Igor...

Jay

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Igor, can you save the Data sheet as a .jpg? Or, do you know if WinRAR is a free program? Because the only link I found for it wants $.
Jay

WinRAR can be used unregistered. But if you can see the file extensions in your OS, you can just rename the extension from .ZIP to .RAR and then WinZIP should be able to open it too, since it has the RAR algorythm, if i'm not mistaken.


But i'll try to fix it. - EDIT: Replaced the file with a proper .ZIP file. I should work without renaming in both WinZIP and WinRAR now.

 

[jayrob]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

I tried renaming it and it didn't work. But I posted a .pdf link that I found right above your last post!

I hope this is that diode! According to rkcstr's graph on page 24 of this thread, it never even got to the max operating voltage of 6.5. Even at 250mA's! (But it does say max operating current 150mA??)
Jay

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

I found a direct .pdf link that works: http://document.sharpsma.com/Handle...ments&fileid=5908EFD87FDB4F6782EE3B2F00523CE4

That would be cool if you could identify this diode Igor...

Great! Thank you for that!


Yeah, i'll be testing 11 of them on my new diode tester driver (circuit courtesy of Phenol). It's a box with two displays, one for current, the other for voltage, and two pots. One pot limits the max current, and the other adjusts the current from "zero" up to the current set by the limiting pot, and the best thing is, the current changes linearly as i turn the pot. Not exponentially, like with regular drivers. It makes testing diodes easy and safe, and eliminates the need for two DMMs and a mess of wires. ;D I hate wires!

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

I hope this is that diode! According to rkcstr's graph on page 24 of this thread, it never even got to the max operating voltage of 6.5. Even at 250mA's! (But it does say max operating current 150mA??)
Jay

Yeah, like i explained in the original post, this is the max CW current officially allowed, for reaching the max CW power officially allowed - 105mW.

Since with diodes, it is their own output power, that kills them (not the current), when a diode is hot, and it's efficiency lower, it can survive a higher current! If you force cool a diode, it can die at a lower current, than when it is hot! Scientific literature is full of examples, when a certain current can be safe when the diode is hot, but as it cools off, the same current can kill it on the spot.

The diode is rated to work at up to 75°C. So at 75°C, the max current allowed to reach 105mW is 150mA. When the diode is cooler, the max current is lower, as it will reach the max power at a lower current.

Basically, what the datasheet is saying is, that when the diode is hot, you can power it with up to 150mA IF required to reach 105mW CW. Diodes have a max safe power, not a max safe current. Because of that, the max safe current changes with the temperature. And quite in the opposite direction, than most people would expect. I did not understand this myself, untill a laser scientist explained it to me.


But as usual, we don't really care about the official max CW ratings are. We always push diodes up to and above their pulsed ratings. The good news is, that if this is the Sharp diode, it could be able to take 190-210mA, translating to about 160-170mW after AixiZ...



The Avg. and Max. Vfs are just a range in which the diodes will operate. The Vf will depend on both current and temperature. The datasheet shows many graphs at 0°C, and that's where the max Vf will be seen. When i was comparing Rkcstr's Vf plot to the datasheet, i was looking at the 25°C curve in the datasheet (the black line)....

 

[jayrob]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

It is interesting that rkcstr's graph for the operating voltage is comparable. 25C is 77F, so we can look at the black line in Sharps graph...

Just speculation at this point, but very interesting!
Jay

 

[thesk8nmidget]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

just waiting for some epoxy to dry and then i should be putting the module in the heat sink and powering her up

WOOT!

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Yeah.. I asked Rkcstr to multiply the powers by the guesstimated amount, and make another plot. When i was doing the comparison, i only used a "corrected" linear line. But the datasheet shows a linear plot too, so that's just as good.

I compared several powers between the datasheet and the "corrected" plot (AixiZ x 1.28) and at 100mA it matches perfectly (103mW in both), at higher powers some discrepancies show up (10mW difference at 150mA). But that doesn't mean anything, because at higher powers, the error from the guesstimated correction factor will become larger, and the diodes vary among themselves anyway, not to mention, that the temperature of the diode in the test was not controlled, so it would only make sense it would show less, even if everything else is correct.


Here is rkcstr's power plot, corrected for the guesstimated losses in AixiZ.

 

[styropyro]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

I got my sleds yesterday, couldn't use them yet because it was Halloween. : Well in reality I couldn't use them anyway because my flexdrive hasn't come in yet, if I'm tempted enough I'll probably just resort to building a DDL to see some 4x/6x light. So if I can resist the temptation I will have my self a 4x/6x pen, if I can't then I'll build a labby...choices, choices. ;D

 

[danq]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

I've only tested the red diode from one of the sleds - decided to stress-test it because I mangled it in the extraction (shaky hands - not from excitement )

But I can say one thing for sure: that red LD is a tough little bugger!!

My testing was done without a proper heatsink - just the bit of metal it pops out of the sled with. Run times were on the order of seconds, because it heated up quickly. But dig this: after I got the preliminary data, I took the current up to... are you ready?
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really ready?
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1.2 AMPS !!!

the output power at that level was about 300mW but falling fast, so I brought it back to zero within a second or two. But the thing is still lasing.

Now, here's my data:

 

[thesk8nmidget]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

the test is all setup and running i will snap some pictures after i go eat some lunch...

weird thing i noticed is after about 5 minutes(set at 200ma) it jumped up from 160mw to 175mw now its at 180mw lets see if it keeps climbing while im gone

all of this is being recorded on my graph as well