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FrozenGate by Avery

SF-AW210 PIV plots/lifetime thread

drlava

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Hi guys, it's been a while since I posted P-I-V plots in volume, since the large roundups a long time ago. Well, I got a new data acquisition card for the rig and built a new control board, so more data will be coming in the future.

Methods:
A few details about the testing rig: It's built on a 16 bit data acquisition card coupled to a MATLAB testing script that I wrote for diodes. It can run ramp tests at almost any current increment resolution, run lifetime tests, automatic cycling, and other tests. The ramp tests that you see me produce are all automatic tests with precise steps, typically in 2.5 or 5 mA increments. The voltage measurements are made differentially right at the diode pins, so the most accurate representation of the diode voltage is recorded. Laser power is recorded via RS232 data feed from a calibrated Scientech 365 power meter, with its head in a stabilizing isoperibol chamber. The diode temperature is kept low via an oversized CPU cooler attached to the mounting rig. Thanks goes to Steve over at ***************** for contributing the diodes tested here. He is in the process of having all of the diode and sled lines that he sells P-I-V tested for quality assurance, and will be posting plots on the data pages.

Results:
These tests were done on two different SF-AW210 diodes, using aixiz type 'blu' ar-coated glass lens assemblies. With these assemblies, the output power was 5% higher than standard open-aperture aixiz plastic.

Diode 1:
LEC_OL-SF-AW210.PNG


Diode 2:
LEC_SF-AW210.PNG


As you can see, the two diodes track each other almost exactly, however diode 2 failed at 275mA with a power output of 325mW. Diode 1 has a noticeably higher Vf than diode 2, however it remains to be seen if this is indicative of higher capability. In the coming weeks I expect to be able to do lifetime burn-in tests to see at which point power output 'sagging' occurs, along with GGW comparisons and hopefully a 12x test or two. Hey, who wants to contribute to another 12x testing fund? You'll get the detailed results right here on the forum :)
 





great work i was just about to search for a SF-AW210 graph then i saw this post this sure helps me allot :D thnx drlava :D
 
Hey drlava...

I just saw all the graphs that you produced for Steve over at L*E*C..
I believe that his request for you to produce some graphs of actual Laser
Diodes he sells over there came from the fiasco about his 120mW "Fake"
LD he was selling...

I think doing a Graph of new batches of LDs received is a great Idea...
Kudos to you and Steve.. :gj:
BTW... I really like your computer controlled test setup...


Jerry
 
Keep in mind that these newer generations of diodes act differently than the old ones.

They graph straight up without showing any kinks or knees.

They can sometimes be run at very high currents for a very short time.

The SF-AW210 diode can be pushed up to these high currents, but they do not last.

Unscrupulous sellers use these "amazing" numbers to sell diodes which will fail in normal use. (i.e. "been tested to 350mW safely")

Peace,
dave
 
I agree with you Dave... but if he (Steve) has a few LDs tested/Graphed from every batch
that he receives.. then the latest graph for the LD being offered would be available.
And the testing is being done by a 3rd party... drlava..
I have no reason to doubt drlava's graphs... and I know they are just a sampling....

The way I see it.. the Graph only shows me that the higher I push the Diode the closer
I come to destruction... Dealing with Electronic design I always double the specs to
what is actually required.... By that I would use the above Graphs to run an SF-AW210
at no more than 250mW to get any life out of it...
I know you would torture it to the sweating point...:D

I prefer to err on the safe side... I'm not an envelope pushing Pioneer like you..;)


Jerry
 
Last edited:
I agree with you Dave... but if he (Steve) has a few LDs tested/Graphed from every batch
that he receives.. then the latest graph for the LD being offered would be available.
And the testing is being done by a 3rd party... drlava..
I have no reason to doubt drlava's graphs... and I know they are just a sampling....
The way I see it.. the Graph only shows me that the higher I push the Diode the closer
I come to destruction... Dealing with Electronic design I always double the specs to
what is actually required.... By that I would use the above Graphs to run an SF-AW210
at no more than 250mW to get any life out of it...
I know you would torture it to the sweating point...:D
I prefer to err on the safe side... I'm not an envelope pushing Pioneer like you..;)
Jerry
I absolutely agree with having some of any batch tested. I was just reminding the community and drlava that once these graphs are in the wild, they will be used AND that they are NOT an accurate picture of the safe use of the diode.

The above graph has NO indicator that 250mA is safe. Those numbers ONLY come from destructive testing now. For example, the experience of the community is that 250mA is NOT a safe current for the SF-AW210 diodes. They fail at a significantly increasing rate above 200mA.

Peace,
dave
 
Thanks Dave, I am aware of the thermal degradation or uv ablation mode lifetime limitation, but it's good that you reminded the viewers here. You may have noticed in the last paragraph: "In the coming weeks I expect to be able to do lifetime burn-in tests to see at which point power output 'sagging' occurs". This is to find just these limitations that you speak of using a series of burn-in tests and ramp tests. When this is done, it's not necessary for members of the community to find out through error and degradation of their own diodes. Looking forward to some cool plots on this one!
 
Dr. Lava;

Thanks to both Steve & you for posting the graphs.

I have also been trying to determine safe operating points for various diodes in my thread:

http://laserpointerforums.com/f38/blu-ray-current-levels-long-life-44746.html

For this SF-210 diode, I came up with 189ma as a safe operating point.

That is ~70% of the first failure point in your testing.

With your testing and some additional testing from Igor,
we will see if that is a good estimate for ~100 hour lifetimes.

I look forward to your additional diode testing.

Thanks;

LarryDFW
 
Last edited:
My experience with the SF-AW210 would concur on that 192ma setting. I used a 230ma setting but the diode only lasted 2 months under medium usage (no more than 2 minutes on at any given time with at least 30 seconds off when left on for more than 1 minute).
 
Thanks for the awesome info !!!!!

I have a SF-AW210 coming in soon. (still waiting on shipping)

Will set it at a safe 180mA and let everyone know how it works out.
 
I absolutely agree with having some of any batch tested. I was just reminding the community and drlava that once these graphs are in the wild, they will be used AND that they are NOT an accurate picture of the safe use of the diode.

The above graph has NO indicator that 250mA is safe. Those numbers ONLY come from destructive testing now. For example, the experience of the community is that 250mA is NOT a safe current for the SF-AW210 diodes. They fail at a significantly increasing rate above 200mA.

Peace,
dave

Hey Dave...

I just re-read our 2 posts...
I was mentioning 250mW for a long life not 250mA....:eek:

[EDIT]
Ignore the Red Text... corrected in post below..:yabbem:
I would even go as high as 300mW and still only be around
100mA for a very long life.. (I know.. that's way to Under
Driven for you guys)


I have a PHR804T in an Aixiz module with an LM317 driver set
at 50mW that I built at about the time I became a member here...
and I use it for tests about 3-5 times a week... and it is still
going strong.


Jerry
 
Last edited:
I would even go as high as 300mW and still only be around
100mA for a very long life.. (I know.. that's way to Under
Driven for you guys)

Jerry

I think with an 8X diode that your right, 300mW's would probably be a really long life...

But you would still have to set current over 200mA's to reach that power with a 405-G-1 glass lens.

For these AW-210 diodes, it has been shown in the past testing of users, that at over 200mA's, they don't last long...
 
:oops:... my bad...:oops:

I agree with you Jay...


Like a moron I'm looking at the Blue graphed line instead of the
Green graphed line...

Using the "correct" green graph line... on both sample graphs I would
not go over 200-225mW of power for those diodes if I expect them
to last a while.. and that would be about 180-210mA..

Sorry for the confusion..:yabbem:
[Edited above..to eliminate that confusion]


Jerry
 
Last edited:
I like your thinking about a 'long life' 8X build though...

I have mine set at a fairly conservative 292mA's, mine is a slightly lower efficiency BDR diode and is under 400mW's at that current. But it is still a ton of power at 375mW's!

So much, that I would think even 300mW's would be plenty for a long lasting 8X build. :)
 





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