Reason of decreasing laser intensity

[Gmkhanani]

Hi everyone,
I really need help regarding my laser. I have bought 2w laser 445nm diode from ebay. At the start it was working fine. There was no issue. I was using current voltage variable power supply for testing. But suddenly its intensity reduced. before it gave first mark on 550 ma where as now it's doing nothing event at 1.2amps. what is the reason behind that and if there is a sol for it please help because importing laser through ebay in my country require lot of time which i dont have.

 

[Teej]

Hi everyone,
I really need help regarding my laser. I have bought 2w laser 445nm diode from ebay. At the start it was working fine. There was no issue. I was using current voltage variable power supply for testing. But suddenly its intensity reduced. before it gave first mark on 550 ma where as now it's doing nothing event at 1.2amps. what is the reason behind that and if there is a sol for it please help because importing laser through ebay in my country require lot of time which i dont have.

What duty cycle were you using, and, is it possible the diode got too hot?

 

[Gabe]

What duty cycle were you using, and, is it possible the diode got too hot?

Sounds about right, I also feel like I remember diodes that get too much current fed to them sometimes go Frankenstein on us, and don't run at full power after it pops.

 

[Teej]

What heat sink was it mounted on too, etc?

 

[Gmkhanani]

not for long period... i was working on for short time interval .... one problem i want to share that after final assembly when i run it .. power supply voltage dropped and c.c light switched means that it require more current .... i could not find sol for it ... can you help ?

moreover is there any sol for this intensity prob ... ? is to possible to fix this prob?

and yes heat sink with a fan was mounted

 

[Gmkhanani]

not for long period... i was working on for short time interval .... one problem i want to share that after final assembly when i run it .. power supply voltage dropped and c.c light switched means that it require more current .... i could not find sol for it ... can you help ?

moreover is there any sol for this intensity prob ... ? is to possible to fix this prob?

and yes heat sink with a fan was mounted

 

[Gabe]

In my unprofessional opinion, I would guess you popped the diode and it's gone Frankenstein on you. No solution other than buy a new diode, if this is the case. Might need another opinion on this.

 

[doubleone44]

It sounds like you where running it on constant voltage mode, not constant current mode. If so, thermal runaway has occured and the diode just got destroyed.. Be sure to set the voltage high next time and to control the current