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Sharp 490nm GH04850B2G 55mW Laser Diode

paul1598419

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Yeah. Next time use heat sink compound. It doesn't setup and cause the module to be not ever removable. It fills in the microscopic cracks and holes so you get better heat transfer, but if you ever need to remove the module, you will be able to do so.
 
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DTR

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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.
Yes no continuous ground on the nano. The flexdrive does have this feature. So for the Nano to use the caes pin for your path to ground you would run a wire from the case pin to the driver negative input. For the flexdrive you can just short the case pin and negative pin running only a single positive wire on the input side of the driver.

I am guessing it is less complicated on switching drivers(buck, boost, buck/boost) to have the current sense on the ground as all Lazeerer's drivers are set up this way. He did make me several batches of continuous ground X-Drives and x-boosts a long time ago by request. Never had any nano modified for continuous ground.

It is a nice feature added on the lava drivers and I believe this is what makes it possible to run the flexdrives in parallel. Anyway it is pretty easy to just run the write to the driver input from the case pin. I actually always do that just out of habit even with the flex. Keeps me from making a mistake going back and forth from different drivers. There are also some images of ways to wire the flex in the manual on the listing page.



 

paul1598419

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Huh. I have some continuous ground X-Drives from a few years ago in my stock. I didn't know Angelos didn't make most of his drivers that way. I rarely ground my driver through the case pin, so this took me by surprise when it happened to me. Thanks for the confirmation, Jordan. :yh:
 

paul1598419

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Yeah, at this part of the visible spectrum only a few nm make all the difference in the world.
 

LtKernelPanic

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Holy crap I go away from the forums for a couple months and come back to this?! :drool: I need to go away more often it seems! :D

Wow. I'll be picking one of these up soon from DTR's shop. I swear I saw him mention it somewhere in the thread but I assume the flexdrives are preset at a reasonable current for long diode life?

Now to find a host... :thinking:

I have one I never used for a 520 build due to a semi-faulty tail switch that needs replacing if I can ever get the tail cap apart. I may poke Lifetime17 about getting one of those amazing teal powder coasted hosts or maybe even a complete build from him.


Is it bad I almost feel like I'm cheating on my Argon with by making this post? :eek:
 

Mosc007

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I should follow these threads a bit closer.

I found it on DTR's site a few weeks ago and ordered one. Arrived and assembled the other night. I do check DTR's site often looking for new Diodes.

I am absolutely wrapped in this diode. I can tell from the 66mw output that DTR is not overdriving these. Absolutely the best way to run them to achieve the best color.

From what I can tell this diode is around the 490nm as advertised. Looks like a pure Cyan color to me. Almost the same as my 488nm Argon.

I did start my own thread but havnt posted many beam shots yet.

Anyway, Here is one showing the color of this diode. This is by far the most exciting color. I cant stop looking at it.


Out of focus shot thru white Copy paper.
 

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Xplorer877

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Holy crap I go away from the forums for a couple months and come back to this?! :drool: I need to go away more often it seems! :D

Wow. I'll be picking one of these up soon from DTR's shop. I swear I saw him mention it somewhere in the thread but I assume the flexdrives are preset at a reasonable current for long diode life?

Now to find a host... :thinking:

I have one I never used for a 520 build due to a semi-faulty tail switch that needs replacing if I can ever get the tail cap apart. I may poke Lifetime17 about getting one of those amazing teal powder coasted hosts or maybe even a complete build from him.


Is it bad I almost feel like I'm cheating on my Argon with by making this post? :eek:
Dude I've been away from the hobby for years and now I come back and see continuous rainbows everywhere!

I might have to pick one of these up. It'll be my first new laser in who knows how long!
 

ZRaffleticket

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Hey there's someone I haven't seen posting in a while. Welcome back!

You missed out on direct green getting cheap, sharp flooding the market with cheap cyan diodes, and just now there's cheap 565 and 575nm dpss hitting the market
 

Atomicrox

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I'm sort of late to the party, just finished my build with a diode binned at 487nm@130mA.

It has two lines at a specific current, and they are separated enough to be clearly different colors. The weird thing is that the main line splits to a lower wavelength when current increases, not the other way around. Increasing the current more will make the lower line vanish, but the higher line doesn't seem to get much higher.

The main line is slightly greenish ███, not what I'd call cyan. Teal, maybe?
The lower line looks more like what I supposed cyan would look, but it might be too blue.
Perhaps the cyan color as shown in monitors ███ can't be reached with monochromatic light.
 

paul1598419

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That is odd, but not unheard of. How did you find these two lines? Did you have a diffraction grating to show them? I personally haven't seen this on my spectrometer, but I have heard from others who have seen it with a grating.
 

Atomicrox

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This diode came from the batch you binned for ZRaffleticket. I guess you didn't see the extra line because it shows up at a very specific current range.

I used a driver with analog modulation set to max at 300mA. That way I can sweep the entire range with a grating in front of it. It's separated enough that I can see both on a handheld "gem identification" spectroscope.

Second time I find a multiline Sharp diode, but this one is a lot more interesting than the other. There is a current setting that makes it output a broad emission that starts on the greener side and ends on the bluer side, with two "peaks". The whole line is coherent and speckled. Kind of like a diode ZRaffleticket posted about, but the line isn't as broad.
 

paul1598419

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Yeah, something like that could easily slip by without me noticing it. I often have many diodes to bin and so I just run the current up well above threshold so I can get a clear peak to measure. I would not run the current up and down while measuring them. This sort of thing happens from time to time and it isn't only Sharp diodes that have dome this. If you hadn't picked a driver where you could change the current from threshold to 300 mA, you likely would have never found this out.
 




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