Hi Everybody.
I like to share some experiance we have made over the last 18 years, and not much have change on the heat and cool qustions. We have in the winter normally -10 to +5 degrees here, like in other contryes like Edison also sayed.
And if you want a stable laser in a large temptatur range, the heat and cool is a much on all DPSS laser.
We never seen a (china) system running at spec / rated output power if all temp isn't in place before you add 5 volt to you blanking pins. I also talked Bridge many times about the heat and cool driver is a must. Cooling ain't enougth.
It is not the right way to do things, that the laser beam must be "warm" things up to working temperature before it is properly set point is reached.
I my world it normal logic that you need H & C in you driver. One think is power stability CW or modualtion. But another thing is if the temperature is aroun 7-8 degrees, where the humidity is lets say it is not good for laser optics, it will also be condensate or moisture on the optical parts. and if you expect to have a laser which will have a long life with many hours of operation. It doesn't help you if your laser head is without any control of the operating temperature on all parts LD + 1 or two crystals depending the laser head you have. And it's normal here with this low temps in winter time. Let say i would take one of our Jenlas laser 5 or 8 watt green laser without heat and cool (of cause i would never do that). But it would not be a great to turn it on at 5 degrees with 20+ watts IR on the optical parts when everything ain't at work temp. It is like peeing in your pants, it lasts only a short time. :-)
One thing we also notes is if you modulate a laser (china without heat and cool) at low temperatur outside in cold conditions, it will never come up to the rated output power. So if you have a 1 watt green DPSS, you are lucky if you have half the output from it. Because you are way below the "correct" set points and the laser do a lots of mode jumps while you move uncontrolled around in temp's.
But i like to see a test from any china manufactor the can show a test spec with a sweep -5 to 30 degrees, and offcause at power up at -5 degrees with and without modulation. That they have a stable system and you have the output power you have payed for. :-) I will start sell there laser also.
We also added Pico drivers from Laserparts.ch on some 1 watt CNI laser and they just run perfect. Better stability, better blanking better output (at all time) can only say it a win win with heat and cool.
It surprise me really much, when there is so much to gain. Why not have the option for the customer. Only CNI have the option up to 2 watts with a H-bridge (heat and cool) solution. Strangely it is not certainly better the higher you are coming up in powerlevel. Hihi...
It is certainly not my intention to sound arrogant or so, but we've just seen so many not well constructed DPSS driver over the the years from the china.
Greetings
Poul
Denmark