Laser life time and modes of failure

[sopark4000]

As most of you know lasers have a listed life expectancy. For example my 1.8W 532nm DHOM has a listed life expectancy of 10,000 hours (this is an actively cooled labby and CNI lists 10,000 hours for similar laser systems).
My 40W Co2 has a listed life expectancy of 5,000 hours.

Now I know that there are many factors that contribute to the life time of lasers, such as how hard you "push" them in the case of our M-140's, the temperature at which the laser is operated, and obviously what type of laser/diode it is (DPSS, gas, direct diode, etc).

I did some searching around the forum and online and one very useful resource I found was this http://www.bob-weber.com/downloads/pdfs/white_paper/WP_laserlife.pdf It only deals with specific plate setting applications but it is interesting.

My biggest curiosity is what happens when different diodes and lasers fail. For example when an M-140 LED's you just get drastically lower powers without focus etc. But I have no idea what happens when a Co2 fails. Also there are different modes of failure and results. Sometimes an M-140 LED's and others it just completely stops output.

Basically I want to know if anybody has any experience or knows what it looks like when different lasers fail (as a result of "old age" and other causes).

 

[DrSid]

I'm not expert in any kind, but I heard often the reflective surfaces of the cavity degrades .. which has major effect on the beam power and quality. And of course, pumping light source can degrade even faster. But I would say that for gass and solid state, everything is fixable, unless it literally breaks.

 

[Zeebit]

How long does it take for a DPSS laser to show significant power loss due to degradation?

 

[bdgreenb]

depends on the crystals used and conditions

 

[Things]

Because of the construction of CO2 lasers, overdriving them enough to fail usually results in the glass cracking at some stage.

For sealed tubes, they also rely on a catalyst to recombine the gasses into CO2, which probably loses effectiveness over time. My guess is a CO2 laser at the end of it's life would just slowly drop in power until it stops lasing at all.

I have a 40W tube that I've accidentally overdriven, but usually all that happens is it saturates, you get a drop in power and a lot more heat output.

 

[Cyparagon]

everything is fixable, unless it literally breaks.

So... if it's not broken, you can fix it?