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Sharp 490nm GH04850B2G 55mW Laser Diode

ZRaffleticket

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Those two diodes Dr. Laser and I bought were most certainly from Sharp. Same exact characteristics as the 480s and 505s, and the new 495's (didn't get the 490's yet, but I assume those will be lumped in too)

The sharp diodes notably have the best divergence of any diode (that we use in the hobby regularly), rivaling the BDR-209's, have the phantom square, have the weird raw output, and have a perfectly circular spot when focused to infinity.
The osram diodes have good divergence, but not quite as good as the sharp ones. No phantom square, normal raw output, and the spot looks more like an hourglass nebula.

And yeah, sadly my set screw wasn't tight enough which caused the module to turn when I would focus the output and it blinked off :(
 
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paul1598419

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I personally have had no problems with any of the Sharp diodes. All my builds are still working and going strong. I think most of the early deaths might be attributed to mistakes made in the build, itself. I use all of my Sharp diode builds often as they are my favorite lasers and get a lot of use.
 

deadshadow

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I personally have had no problems with any of the Sharp diodes. All my builds are still working and going strong. I think most of the early deaths might be attributed to mistakes made in the build, itself. I use all of my Sharp diode builds often as they are my favorite lasers and get a lot of use.
And considering the fact that most of the times we overdrive them and double or even triple the recommended from datasheet output. Sharp diodes are very nice on divergence and durability i just don't like the box reflection that force us to use a 3 element or acrylic lens.
 

paul1598419

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Yes, that rectangular artifact is a PITA, but they have great divergence specs and the alternatives are much more expensive.
 

ZRaffleticket

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Hey, just a heads up for everyone about these diodes: For those using the nano driver, you need to run the negative lead through the driver, and ground to the host after the driver as opposed to grounding the negative lead to the case pin. Battery -> driver -> LD -> driver -> host -> battery........rather than Battery -> driver -> LD -> host -> battery

I can only conclude there is some regulation going on from the LD- to Vout. If you ground the LD- to the case pin of the diode, you'll experience short run times that lead into strobing and turning off. Hasn't killed a diode, but it's still not something you want to subject these things to.

A huge :thanks: to Paul for troubleshooting and figuring this out. I sure wouldn't have thought to check this.
 

paul1598419

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Just a clarification on this same issue. I had been grounding all diodes from this batch through the case pin to the driver. When I used one of these to build my own EDC build, it would cause the diode to decrease in power, cut out completely, and then cut on and off. I initially thought it must be a heat issue, but after trying various ways to stop it from happening, I found it would always occur when the host was together, but never when the host was apart. I finally ground the heat sink to the host only with a clip lead and found it happening while the build was apart. This told me it had to be the grounded case pin. Once I removed it......problem solved. This was using the Nano Boost driver with the 490nm diodes.
 

Lifetime17

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Hi,
Thats great info I been using Flex Drives and X Boosts no problems with this new diodes using the case pin..

Rich:)
 

paul1598419

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I suspect the current sense is on the low side of the driver's connection to the diode. If you use the case pin to ground to the diodes cathode and also use the negative input to the drive to connect to the battery, it cuts the current sense out of the driver. If this is the case, I would never even ground the battery through the diode's cathode connection as this will eventually cause all sorts of problems.
 

ArcticDude

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Just placed my order.. :p

Looking forward to see the beam IRL :wave:
 

paul1598419

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Hope you get a low wavelength one, Tero. Mine is just under 488nm after 30 seconds of on time. It is a sky blue color without a trace of green in it anywhere. :D
 

cyberdoc

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Hi Paul:

Sanwu wrote that my 488nm-490nm Pocket laser is on its way. I requested one that was measured at 488nm, and really hope I receive it. You and others who’ve seen the 488 nm beam first hand have made the anticipation almost unbearable. ;) Thanks and Please Take Care.

-cd
 

paul1598419

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I am very curious if Sanwu is able to bin these by wavelength. If yours is a true 488nm, it won't have any trace of green in it at all. Let me know once you receive it.
 

Shotgundrums

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Round 1 for the pens. This color is gorgeous!! To me it’s on the edge of turquoise. DTR set it to 150mA. Makes for a really nice pointer. I’ve been playing with it for a little bit running on ol’ AAAs. Enjoy:beer:
SGD
 

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paul1598419

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Nice ECD build, Josh. I like it. I think if you are going to put these in pens without heat sinking, you need to keep the current lower than the 200 mA and above range. I know from experience how hot these can get. BTW, that looks like a low wavelength one from your photos. I have one that looks just like that, with no green in it at all.
 
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cyberdoc

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I am very curious if Sanwu is able to bin these by wavelength. If yours is a true 488nm, it won't have any trace of green in it at all. Let me know once you receive it.
Hi Paul:

I’ll post as soon as I receive it. I really hope that it’s a true 488nm! Thanks for your interest. Please Be Well and Take Care. :D

-cd
 

Shotgundrums

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Yeah I really like it:D. I asked Jordan to keep it running low at 150mA. I’m running it short bursts. I’m leaving for the states today and when I get back I’ll probably start building a red with an LPC-826. Oh, and I finally got my modules... lol
SGD:beer:

Nice ECD build, Josh. I like it. I think if you are going to put these in pens without heat sinking, you need to keep the current lower than the 200 mA and above range. I know from experience how hot these can get. BTW, that looks like a low wavelength one from your photos. I have one that looks just like that, with no green in it at all.
 
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