In how cold temperature does a 445nm still work?

[TuhOz]

Hello,

I've been wondering this as I got my 445nm ready.

Strangely I couldn't find answer to this question.

So can I use a diode 445nm laser in -5C....-15C?
Can low temperature damage the diode/driver?

Winters are cold in Finland... so I want to know how much I can use it outside

Btw my laser is M140 diode w/ Flexdrive @ 1.2A

Thanks!

 

[Cyparagon]

The diode and circuitry will be fine, but battery performance will suffer a lot.

 

[Sigurthr]

It was -15C here last night in northern Michigan, no problems with my 50mW 445nm pointer... other than my fingers not wanting/able to hold down the pushbutton well. I wish pointers had tail clickies.

Batteries do not like the cold though, they will die if kept under their minimum temps.

 

[Moebius]

The clicky on my Cree sometimes gets "funny" in really cold weather.

 

[TuhOz]

Thanks for the answers everyone.
Just wanted to make this sure as my DPSS laser doesnt like cold. Hehe.

Batteries do not like the cold though, they will die if kept under their minimum temps.

Larry's 18650 cell's should work from -20C to +60C
18650 Batteries & Chargers

 

[Bionic-Badger]

Yeah, those DPSS crystals don't like the cold weather at all.

 

[jimdt7]

Yeah, DPPS lasers are very sensitive to wheather conditions !

Jim

 

[Event_Horizon]

Actually, laser diodes and laser crystals LOVE the cold. Diodes run best when they're submerged in liquid nitrogen, in fact. Same with DPSS crystals.

The problem is that cold diodes shift their wavelength output. What used to be an 808nm diode at room temperature is now probably closer to an 812nm diode in the freezing cold. The diode shifts right out of the absorption band of the DPSS crystal and your DPSS output drops to nothing.

Driver circuits like being cold as well, though perhaps not liquid nitrogen cold. They should be fine even in freezing cold weather.

What won't be fine is your batteries, and some types of mechanical buttons and switches. So for the sake of those, keep your laser warm!

 

[Cyparagon]

laser crystals LOVE the cold.

All of my experience says this is wrong.

 

[geekypyro21]

No, the laser as a whole (DPSS) hates the cold. As the individual electronic components get colder they become more efficient, which may change how they work with the other parts, ex. the wavelength of the 808nm diode changing.

 

[Event_Horizon]

Precisely. I've driven a Nd:YVO4 + KTP crystal combo at -78 degrees C and it worked better than it did at room temperature.