Скачать или смотреть LE N2 Laser - RUNNING (longitudinal excitation nitrogen laser)

I still can't believe it. This is the very end of a project I started over a year ago and it feels like I've been working on it for ages (besides, all the tools and machines to get there including a two-stage vacuum pump cost a small fortune). I can't tell you how happy I am to have succeeded in building it. Now let's get down to the technical issues.

My concept was to build a sealed laser assembly (I used epoxy glue and solder). Except for the pump outlet, I really did that. For the mirror alignment, I used a HeNe-Laser to preadjust the mirror and microscope slide glass. I prefer the gas laser over the diode laser because it produces low modes - my tube produces a TEM10 mode. The prealignment was done in about an hour. Right after that, I glued the brass window carrier tubes to the copper channel tubes.
The alignment in the aftermath of this tight glueing is very limited but sufficiently wide-ranged to permit perfect final alignment.

The laser took some minutes of warming-up and degassing to start showing good laser action. I also needed to find the right way to attach the hose ( laser output strongly depends on the right leakage rate). So I first saw a laser spot with a blue circle around it. I already knew this behaviour from the alignment procedure and knew that a little tilting of the output coupling window would do the trick. The remarkable thing is that laser action starts even with two or three transits through the laser channel and using plain air as filling.

In the video it looks kind of strange, but the laser emits a pulse on every discharge that occurs. My camera seems to have serious problems capturing these pulses. Sorry for that, I did my very best.
Divergence is at least 3-5x better than with my transversal N2 laser at atmospheric pressure.
I will make a slide show of some good pictures I took and publish that later on.

The topology is quite simple. I use a 1nF / 40kV capacitor in parallel to the spark gap and 2nF in series to these. The end points connect to the discharge tube and to a loading choke. The power supply unit attaches to the spark gap terminals. The gap is approximately 12mm wide and I use hemispherical stainless steel M8 nuts which means the operating voltage is between 20kV and 25kV. Judging by the discharge color I assume the working pressure is somewhere between 1 and 10mbar.

My goodness... it works! Have a nice day.


Thanks go to all the people that have been interrested in my work ever since I started - you've helped me to continue whenever motivation hit a lull.