Hi all,
I am not in the trade, but I am wondering what the pulse duration is like for commercially available CO2 lasers. I'd imagine there are ns CO2 laser out there. Can the pulse duration be any shorter?
Cheers
Hi, Pulsed CO2 laser is basically works using a chopper, so that the CW beam is chopped into pulses with time duration related to chopping rate.
Hi Sedao
We use a direct low frequency generator on the our CO2 electric supply device. In this case the repetition rate can be varied from CW up to 1 GHz.
Pulsed CO2 laser could be in the range of ns to ms, used mainly for thermal processing and as a thermal source.
Regards,
Nadjib
Thank you very much Nadjib and Hamid!
The long wavelength of CO2 laser makes it an interesting option for processing glass probably as there is a good absorption. If possible I'd like to know a little bit more about the focus spot size of CO2 lasers? Would it be diffraction limited (so approximately 5-10µm as minimum possible) or there are other constrains leading to bigger spot in reality?
I'd appreciate it if anyone could comment on this.
Ta
p.s. How are you Nadjib? Greetings
Dear Sedao,
we developed a q-switched CO2 laser with a minimum pulse duration of about 50-100 ns, which is also commercially available.
Shorter pulse durations can only be achieved by mode-locking TEA-CO2 lasers. But this is less usual because of the required high pressure inside the active media.
Concerning the spot size we can achieve a diameter of about 80 µm (this is already very good) using a common meniscus focussing lens with a focal length of 1.5 inch. In comparison to 1 µm wavelength, the variety of focussing optics is limited because of the required optical material (mostly ZnSe, Ge).
We already did a lot of investigations concerning CO2 lasers and glasses, the generation of CO2 laser pulses etc. There are also several papers. If you like to discuss some more aspects just drop me a short mail.
Best,
Stephan