How does heat shorten laser life?

[EpicHam]

We often hear about how overdriving a diode will shorten its life , fry the dye and what have you.
That I get.. (actually I don't get it technically)

What I don't get is how does heat shorten the life of a laser.

I mean.. there's no moving parts.

Diode, driver , electricity source. Bam , laser.

I did a quick google and find a site pelting my face with Twice Law and Arrhenius Law about how endothermic chemical reaction rate goes into hyperdrive when the temperature goes UP but what I don't get is... whhhy and how does it relate to components used in lasers?
Effect of heat on electronic devices?Technical Information?Apiste Corporation

How does heat degrade it?
How MUCH does it degrade it?
And how can we protect our lasers so it can live a long and happy life?

 

[Cyparagon]

The same way heat damages anything else. It causes changes in the molecular structure.

If you're worried about diode life, you can start by not running the damn thing at 3 times its rated current.

 

[ARG]

How MUCH does it degrade it?
And how can we protect our lasers so it can live a long and happy life?

-Depends on how much heat for how long. From personal experience, where I put the TEC in backwards on a laser, it can degrade the diode a lot.
-Keep the diode cooler.

 

[Things]

If you're worried about diode life, you can start by not running the damn thing at 3 times its rated current.

^ this. You can't really expect to overdrive something as much as we do and get the full lifetime out of it .. rated current exists for a reason.

 

[VisibleGreen]

Think of the filament of old lightbulbs. With enough current the metal will glow red hot and with even more current it will burn out completely.

 

[123splat]

Actually, in an incandescent lamp, and in addition to crystalization caused by the thermal changes,,, it is the physical shock from voltage changes when turning on/off repeatedly.

 

[Cyparagon]

^The biggest factor is vaporization of the tungsten. They still burn out if you never turn them off.

 

[ba12348]

Now I'm curious, if heating a diode will cook it and shorten its life, will cooling it extend its life? i.e. would a laser diode with some sort of liquid helium super cooling system last far longer than expected? I know computers better than I know lasers, and processors run better the colder they are.

 

[Cyparagon]

Now I'm curious, if heating a diode will cook it and shorten its life, will cooling it extend its life?

Marginally. Doesn't matter how cold your processor is running - you can't clock it to 27GHz. Besides, around here, most people don't want it unless it fits in your hand and can roll off a table :shhh: