new laser?

The nitrogen in the air is what lases.

No beam stop.

Well,,,,,,back in the 1800's or so there were a lot of electrical experiments concerning enclosed tubes of gas: dark spaces, cathode rays, etc (do not know all of the things discovered). Varied pressure,varied voltages,etc. Apparently what was NOT done was vary the distance to an anode that had a hole in it and have another electrode afterwards.

I understand that some ceramic "alloys" are getting close.

The Cymer DUV eximer light sources (used to make the light to expose ICs) are similar pulsed transverse-discharge geometries. They use various exotic gasses to get down to as short as 192 nm. They may have mirrors... not sure about that.

They use saturating magnetics to generate the electrical drive. Some are single-chamber, some are MOPAs.

r.

Sounds a bit like this

which seem to depend on spiral liquid crystals as the lasing element and th e optical cavity. You align them with an electric field and because the str ength of the electric field influences the pitch of the spiral structure, y ou also get to tune the lasing frequency. Cool.