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Laser Diode getting weaker and hotter after ~5 secs from being started

الليزر

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Hello again, as the title of topic states... I was trying out a new diode that I just got ( NUBM49 ) and after starting it... It starts strong but then the power fades away ~5 secs later gradually to a low power "mode"

Also the diode gets extremely hot.

What could be the reasons and how to fix the problem ?
 





WizardG

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I was just testing the diode raw with no heatsink applied until now
Well there's your issue. If you want the diode to live longer than 5 seconds it MUST be heat sinked or it will die in very short order. If it still lases at all it will likely have reduced power and a short lifetime when placed into a proper host. You may want to save some time and order a new diode before you go any farther with your build.
 

الليزر

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Well there's your issue. If you want the diode to live longer than 5 seconds it MUST be heat sinked or it will die in very short order. If it still lases at all it will likely have reduced power and a short lifetime when placed into a proper host. You may want to save some time and order a new diode before you go any farther with your build.
Alright then. I appreciate your help and forwardness with no silly meaningless replies.

Thank you !
 

Unown (WILD)

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Alright then. I appreciate your help and forwardness with no silly meaningless replies.

Thank you !
Well it is kinda silly that you didn't know that the diode needs heatsinking.
 

الليزر

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Well it is kinda silly that you didn't know that the diode needs heatsinking.
No pity in not understanding a thing, I am a new guy keening to learn more about this field & I am pretty sure once you were in the same boat of mine.

So no need to act annoyed infront of others to show how cool you are, you are a staff member who is supposedly to make this place better... but the role seems like its making you stuck your nose up in the air mocking others around.

Also, if you just want to argue you can go ahead & fight with others on "Politics and General Debates Thread", you got plenty of activity in there.

One thing to add; if you won't respect me, at least respect the other members & the role you got.
 

Unown (WILD)

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No pity in not understanding a thing, I am a new guy keening to learn more about this field & I am pretty sure once you were in the same boat of mine.

So no need to act annoyed infront of others to show how cool you are, you are a staff member who is supposedly to make this place better... but the role seems like its making you stuck your nose up in the air mocking others around.

Also, if you just want to argue you can go ahead & fight with others on "Politics and General Debates Thread", you got plenty of activity in there.

One thing to add; if you won't respect me, at least respect the other members & the role you got.
You need to calm yourself down... It was a light hearted statement. Yes I knew that when I first built my laser. I don't appreciate your insults. It seems you have a huge chip on your shoulders and I suggest you get rid of it real quick.
 
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What's the chance this new member knows about the political thread here, but not about putting a laser diode in a heat sink ?

Also Unknown (WILD) did not act " annoyed " as accused, he simply said it seemed kinda silly which it does, but then again trolling is a silly waste of time.
 

WizardG

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No pity in not understanding a thing, I am a new guy keening to learn more about this field & I am pretty sure once you were in the same boat of mine.

So no need to act annoyed infront of others to show how cool you are, you are a staff member who is supposedly to make this place better... but the role seems like its making you stuck your nose up in the air mocking others around.

Also, if you just want to argue you can go ahead & fight with others on "Politics and General Debates Thread", you got plenty of activity in there.

One thing to add; if you won't respect me, at least respect the other members & the role you got.

On the one hand..it IS kind of a basic thing to never operate our diodes without heatsinks. Expect a bit of ribbing الليزر

On the other hand..I'm sure many here can relate to the youthful experience of dinking around with electronic components and winding up with a 2n2222 shaped burn on index finger, thumb, or both.

There IS a learning curve for electronics. But starting up the steep part of the slope with 5-watt diodes can get expensive....fast!
 

Giannis_TDM

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Also in my opinion starting with such a high power diode is highly idiotic and an outright middle finger to yours and others' vision.
 
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People should use caution and that means educating themselves 1st, a new laser enthusiast should know something so basic as needing to heat sink the laser diode, so it's fair to wonder if they understand any laser safety at all.

The divergence of these multi watt multi mode laser diodes is really poor, so I'm not worried about eye hazards to persons in the far field especially with the inability of the human hand to hold perfectly still, but when we finally get some awesome quantum dot laser diodes mass produced for the holo projectors that will be built into our phones and household display devices, I really hope our hobby hasn't been ruined by people who didn't take the time to learn.

I expect OP may be trolling, but who knows, maybe not, still we need to impress upon new people the need for laser safety somehow in a nice/appealing way rather than expressing disdain for what we know is a threat to our hobby and possibly someones innocent housemate who could get flashed at short range by a novice.

So to الليزر I say PLEASE use caution and wear laser safety glasses designed to attenuate the wavelength you are working with and be certain you don't shine your laser at anyone or any vehicles and don't allow your lasing to distract/annoy anyone, enjoy but always lase safely.
 

Giannis_TDM

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People should use caution and that means educating themselves 1st, a new laser enthusiast should know something so basic as needing to heat sink the laser diode, so it's fair to wonder if they understand any laser safety at all.

The divergence of these multi watt multi mode laser diodes is really poor, so I'm not worried about eye hazards to persons in the far field especially with the inability of the human hand to hold perfectly still, but when we finally get some awesome quantum dot laser diodes mass produced for the holo projectors that will be built into our phones and household display devices, I really hope our hobby hasn't been ruined by people who didn't take the time to learn.

I expect OP may be trolling, but who knows, maybe not, still we need to impress upon new people the need for laser safety somehow in a nice/appealing way rather than expressing disdain for what we know is a threat to our hobby and possibly someones innocent housemate who could get flashed at short range by a novice.

So to الليزر I say PLEASE use caution and wear laser safety glasses designed to attenuate the wavelength you are working with and be certain you don't shine your laser at anyone or any vehicles and don't allow your lasing to distract/annoy anyone, enjoy but always lase safely.
Are you really kidding me now? Do you think that 7w won't do much due to... divergence? the NOHD will still be in the hundreds of feet, a stray beam will easily be able to do damage, not to mention that him having gotten that 7w diode instead of a lower power one implies that he is also chasing power for burning and burning happens at close range, who knows if he wants to show it to his friends and some reflected beam hits them at close range, gone the eyes are... It is absolutely a danger to others too.
 
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I would be interested to know what the real exposure to a human eye at hundreds of feet would be with a nubm44 doing 7w which if it's a sanwu means a G2 lens which is as you know a short FL lens, I don't think sanwu offers the G8 lens.

Lets say 300 feet, how much surface area will the giant bar cover and how big is a human pupil, is there even 5mw at 300 feet......I'm not talking about exposure duration of the human blink reflex ( 1/4 second ) but just mw per the area of a human pupil.

8 feet wide by 3 inches thick is my estimate for a nubm44 with a G2 @ 300 feet ( it's actually even wider IINM ) and a human pupil at night is what 1/4 inch round but lets call it square even giving it more area.

That's 4608 1/4 inch squares in an 8 foot by 3 inch bar of light @ 7000 mw, that means less than 2mw into a human pupil at night from a nubm44 with a G2 lens @ 300 feet.

I'm not saying people shouldn't be careful, quite the opposite, but my statement about far field eye damage was correct, now as a distraction hazard yes, also at middle distance you can hurt someone and must be careful not to and I do not advocate flashing anyone at any distance.
 

الليزر

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On the one hand..it IS kind of a basic thing to never operate our diodes without heatsinks. Expect a bit of ribbing الليزر

On the other hand..I'm sure many here can relate to the youthful experience of dinking around with electronic components and winding up with a 2n2222 shaped burn on index finger, thumb, or both.

There IS a learning curve for electronics. But starting up the steep part of the slope with 5-watt diodes can get expensive....fast!
I was simply testing it out for like 10 secs max then turning it off.. and the input power was approx 60%

but I didn't know at time to must use the heatsink for a testing of the mentioned duration above, although now the diode is inside of the module for longer "tests".

I have more work to do on focusing the beam right now.
 




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