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Feeler: 495nm and 488nm diodes

styropyro

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yes that is what I have. is that good or bad? gonna go read your thread now
 



DTR

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styropyro

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Oh awesome. This is a different diode then! I'll throw one into an aixiz module and run it against an earlier 495nm diode.
 

DTR

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Yea if you can put them side by side you might be able to see if there is a hint of difference. Lot of interest if these move a little more to the blue than the last release.:beer:
 

Singlemode Laser

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I would not say it is good or bad just that it is the GH04850B2G diode not the one from the previous release. We won't have hard info till some of them get spectroed but I did do a power test on them in the thread so far.

https://laserpointerforums.com/f52/sharp-495nm-gh04850b2g-55mw-laser-diode-102603.html

Nice power test Jordan. It matches very well with the test I did on the previous 495nm batch:


https://laserpointerforums.com/f40/sharp-gh04955a2g-new-495nm-diodes-102136-4.html#post1512110

Singlemode
 

styropyro

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WOW....just tested one of the diodes against an older 495nm and it is very noticeably bluer! I'll break out the argon ion soon and compare it to 488nm. I've packaged up the diodes in the GB...about to start printing off labels
 

CurtisOliver

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Very interesting Drake. I'd love to see a comparison of the older 495, the new one and an argon if you can. :)
 
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paul1598419

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I have 20 diodes ready to test. They have the iteration SB308B292 stamped around the diode's window. I know everyone is excited that these might be 488nm diodes, but they are clearly marked as 495nm diodes on the outside of the package. The USB2000 will tell all shortly. :D
 

styropyro

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All diodes have been shipped! I still have to send tracking info to a few of you.
 

paul1598419

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I have results for the first five diodes I tested. They are a new wavelength, for the most part, at current ranging from 55 mA to 130 mA with temperature held constant.

in order of wavelength they are:

486.8nm at 55 mA
487.4nm at 70 mA
487.2nm at 55 mA and 488.3nm at 130 mA
490.3nm at 120 mA
491.8nm at 100 mA

What I think I am seeing is that between threshold current and 130 mA the diodes increase in wavelength by ~1nm. I am very excited about this, but I have 15 more to test.
 

Singlemode Laser

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Great job Paul!

The centre wl seems to match the advertised one and also the wl spread. We really have some 488nm here ;) Can't wait to see the measurements of your remaining one!


Singlemode
 

paul1598419

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Thanks, V. No one was more surprised than I was. I have only tested five so far and have fifteen more to go today. Maybe there will be one close to 495nm among those.
 

styropyro

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Thanks for the testing Paul! That's awesome that these are ~488nm...doesn't surprise me after seeing it in person though. When I first fired it up all I saw was blue! I'm glad nobody bought the osram 488nm diodes considering how cheap these ones turned out to be. The only thing I hope is that people who were wanting actual 495nm won't be disappointed.
 

paul1598419

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Thanks, Drake. Now that I've measure eleven, it looks like most are around the 490.5nm wavelength. Not that far off, but not 488nm either. I will be keeping a 487nm one so it will shift up to 488nm when I drive it at 250 mA. I'll also be keeping a high wavelength one too.
 




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