Use Dry nitrogen with silica gel dessicant packs. Have Heated AR coated windows. You'll need to potentially heat any DPSS.
~
I've done outdoor laser shows with Ion systems below freezing. We at least had a elevator room to put the heads in when off. With SP 165s,that required immediately injecting antifreeze into the system when off and dashing into the building quickly. You may need pure alcohol to get condensed water off things like beam table mirrors.
~
Antifreeze finds its way to the optics and is sticky.
~
ON very cold days there is no humidity or dust in the air, so you'll need fog machines. Our show was very disappointing when had no fogger and cold air.
~
Most large blue and green diode can windows, as well as some single mode reds, are not hermetically sealed, so water condenses on the back side of the can window... Ask me how I know.. :-( I've tried to clean a few, and they often leak!
Ste
Last edited by mixedgas; 08-14-2018 at 16:27.
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...