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505 nm laser diode

DTR

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Yep just keep in mind that the unique qualities of this diode are that they are low in wavelength. The ones I had were also a SB14 model and they were already on the high side averaging around 509nm. Pushing them hard you start getting closer to the 515nm / 520nm diodes. They can certainly be run harder and not sure exactly how much they shift based on current but if your goal is to have it as close to the 505nm as possible you may want to consider being more conservative with it.🍺
 



reloader45

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Hello,

at 100 mA this diode looks green. But direct compared to my 532 laser, it looked bluish green. I am not able to see absolute colors!
For example my 488 nm laser looks babyblue to my. But in an direct comparison with my 450 nm laser it turns . greenish in a split of a second.
Did you ever see the picture of the blue strawberrys that look red, because our brains learned that they are red?
That is the reason will I must smile, when some people declare, that they can see the absolute wavelength from a picture of a laser beam.

best regards

Edgar
 

paul1598419

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All of these Sharp 505nm diodes tend to do better if not driven harder than 350 mA. I usually drive them at 275 mA which will give you an output well above 100 mW. These tend to shift more with temperature than with current, though. I still have a list of all the iterations I tested for wavelength around here somewhere. If you do push yours to 500 mA I would heat sink it well as that is pushing it pretty hard.
 

reloader45

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Hello,

I will set it to 280 mA like the 488 nm diode. I thought , it could not take this current, because it is a 35 mW diode.

best regards

Edgar
 

paul1598419

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You will get a rectangular artifact using most glass lenses with this diode. The 2 element 520 AR coated lens from DTR eliminates it as does an acrylic lens that comes with most modules. There are some others too, but they need to be tried on an individual basis.
 

reloader45

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Hello,

today I set the driver to 280 mA. The color is nice green with a blueish tint. But the output is poor. I only get 70 mW with a glas lens. I can not find a binning on this diode, but I think it ist a poor one.

best regards

Edgar
 

paul1598419

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Is there a number around the window? SBxxxxxxxx? I have many binned by that and may be able to tell you more if it is one I've seen before. At 70 mW that is very low for 280 mA of current. You could be right. It might just be an inefficient diode.
 

reloader45

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Hello,

Didn‘t you see my photo with the number?

best regards

Edgar
 

paul1598419

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I had to go looking for it, but I did find it. Unfortunately, it is a later iteration than any I have seen before, so I don't have any specific information to give you about this diode. But, they are all similar in that they usually give more than 100 mW of optical power when driven at 275 mA. How much more depends on the lens used as well as the efficiency of the diode. Yours seems to be a particularly poor one. That, or the lens you used is horrible.
 

reloader45

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Hello,

I don`t think that I have poor lenses, all of them are AR coated and i use special lenses for green laser.
Maybe my cheap LPM don`t like green laser. I can not test the remaining diodes at this current without pressing them into heat sinks.

best regards

Edgar
 

paul1598419

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Hello,

I don`t think that I have poor lenses, all of them are AR coated and i use special lenses for green laser.
Maybe my cheap LPM don`t like green laser. I can not test the remaining diodes at this current without pressing them into heat sinks.

best regards

Edgar
Maybe. What LPM do you have? I'm sorry if you stated this somewhere, but my memory isn't what it used to be. I have seen some horrible LPMs here recently and if it is one of those, then.....case solved.
 

paul1598419

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Hello,

I have the LPM from laserpointerstore:



best regards

Edgar
OH!!!!! That explains a lot. That LPM only has a TEC, a pot for "zeroing" the display, an LED with a current limiting resistor and a digital volt meter. It is likely the least accurate meter on the market today. I would not trust it to give you anything close to an accurate measure of any laser's power.
 

reloader45

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Hello,

I bought it, before I joined this forum.


best regards

Edgar
 

paul1598419

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Yeah, live and learn. I have also purchased some questionable items when I was new to this. It is too bad there aren't the number of LPM sellers around like there used to be. I would check with Jerry, lasersbee. He sells some very good hobbiest LPMs that are very reliable. I have four LPMs, but one no longer works. That was my fault as I tried to resurface the TEC on my Laserbee. That ruined it. I could send it to you for the cost of shipping it to you. Jerry could repair it for you and recalibrate it. Just a thought.

It is the 3.2 watt Laserbee with data logging.
 




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