Lasers and the Cold do not mix (Why you should not run or store your Jtech Laser in less than freezing temps)

Lasers and the Cold do not mix (Why you should not run or store your Jtech Laser in less than freezing temps)

There is now a winter artic blast moving across the country and we get asked all the time,

“Can I run my laser if it is below freezing in my shop?”

The answer is pretty simple and has its origin from physics. If your laser is in your shop and below freezing, DO NOT run your laser. You have the high chance of it being damaged by what is called “thermal shock”.

We recommend never allowing your laser to get below freezing as well. If your shop is in the cold, bring in just your laser head to the nice warmth of the house. This way, you don’t risk any damage from temperature issues.

From the specifications of the laser head you can see the recommended operating and storage temperatures are both above zero degrees Celsius (freezing).

Example specifications for the 24W laser head. All of the lasers have the same temperature specifications.

So, what is thermal shock and what can happen to my laser?

Thermal shock refers to the stress and potential damage that can occur in materials when they are subjected to a sudden change in temperature. When a laser is in operation, it generates heat, and if this heat is not evenly distributed or if the laser medium is subject to rapid temperature changes, thermal shock can occur.

There are semiconductor mirrors inside the diode cavity that are sensitive to thermal shock. If it goes below freezing and then when you turn it on the temperature will rise to about 50 degrees C, the change in temperature will cause the mirrors to expand so quickly that they will crack. This is also true of the glass lens and lens cover.

Cracked lens cover resulting from thermal shock.

You can see a quick video showing the effects of thermal shock on a glass container here:

It is a pretty catastrophic event that can happen.

Now, if you keep the laser in a warm area and then just hook it up right before you start the burn, then the laser might not get down to freezing temperatures while it is running. However, this assumes that you are paying close attention to it so that it doesn’t sit idle in the sub freezing temperatures for long enough for it to get cold enough for thermal shock. This would be a tricky exercise as you don’t know how long this time is to be able to tell where you would be safe and not damage the laser.

Let’s just hope spring is on the way and we don’t need to worry about sub zero temperatures any more!

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