minimum temperature for safe operation of green DPSS lasers?

[ixfd64]

I know that a laser should not be stored in a very cold place, since thermal shock can damage the components when the laser is turned on; hence, most laser hobbyists consider it a bad idea to put lasers in freezers. However, I have the following questions:

1. Does anyone know what is the minimum temperature at which a green DPSS laser can be used without risk of thermal shock?

2. Would it be a bad idea to put a laser in a refrigerator instead?

3. Earlier today, the temperature at Chicago was just below 0° C. I briefly used my Spyder after leaving it in a car for two hours. In hindsight, I don't know if that was the brightest (pun intended) idea. I know the temperature inside the car was somewhat higher, but was it still a bad idea to turn on my laser right after taking it out of the car?

4. If thermal shock does damage a laser, will its output drop slightly, or will it suddenly stop lasing completely?

Thanks.

 

[Slipstream]

To answer #4

From my experience my red LOC died instantly when I took it out of the freezer and turned it on.

 

[vitalyx]

I used mine when it was -20°C for several minutes continuously and it's fine. But it was room temperature initially.
http://laserpointerforums.com/f48/fun-lasers-20-c-4-f-46283.html
Given the fact how quickly you can warm up the laser with your hands, why risk?

 

[3zuli]

my DX50 worked fine (I think even better than in room temperature) while I was playing with it @ -7°C. it was attached to a tripod - no warming by hands
at room temperature, it usually makes mode-hopping and at -7°C it didn't

 

[Jaseth]

One thing to take into consideration is that, unless your laser is 100% waterproof, cooling it down and then taking it into warmer surroundings will cause condensation to form inside, potentially leading to shorting it so it fries.

Seb

 

[Things]

Also, the KTP crystal actually prefers to be warm, so cooling it greatly will reduce the performance.

 

[laze_doctor]

I was recently looking into this myself. Turns out DPSS greens are fine to use in the cold. You'll get little (or no) output as the temperature gets colder, but you won't cause damage to the laser until around -40C. At that point the extreme cold causes the metal to shrink slightly -- which can damage the alignment of the optics, etc.

 

[Flaminpyro]

@ Things This is good to know that it likes to be warm, Thanks !

Thank you Seb for the nice picture, very beautiful !

One thing to take into consideration is that, unless your laser is 100% waterproof, cooling it down and then taking it into warmer surroundings will cause condensation to form inside, potentially leading to shorting it so it fries.

Seb