Electronics360: "The Birth of Laser Weapons"

While still a student at the University of Michigan I took a job as a production technician at Trion Instruments. Trion as I understand it was the first commercial laser company in the world.

I eventually ended up as an engineer doing research and development. We had developed the technique of Q-switching and one of the problems we ran into generating high peak power laser pulses (multi-megawatt) was based on what is called the Lamb effect. The leading edge of a high intensity pulse heats the air changing the index of refraction of the air. This in turn causes the velocity of the remainder of the pulse to increase and the trailing portion of the pulse starts to catch up with the leading edge. As the pulse shortens the intensity increases and ends up breaking down the air.

We therefore had to increase the diameter of the beam to keep the power density below the point where it would break down the air. I have never seen this mentioned in any articles about high energy laser pulses and wonder if this has been a problem.

At that time (mid-sixties) we were working mostly with ruby and neodymium doped glass and sometimes YAG.

I have been out of the laser business for many years but still try to follow what is going on. It's always fun to find mention of some of the work we did way back then.