Building lasers...

When I joined the now defunct Department of Physics at Essex University in 1971, my first task was to build a CO2 ‘TEA’ laser. My knowledge of mechanical and electrical engineering was practically zero, and it is a constant source of wonder to me that I never managed to kill myself with the 30 kV power supply.
 
In 1974, my SRC studentship at an end but my PhD work quite unfinished, I was taken on to the staff as a ‘Post’ Doc, and given a project to build a high stability TEA laser for use in Edinburgh at Heriot Watt University. The application was to optically pump a spin-flip (tuneable) Raman laser. A source of tuneable laser radiation was the Holy Grail of the laser community at the time.
 
The objective was to build a laser capable of sustained operation at 100 pulses per second – the standard at the time was about one pulse per second – with unprecedented spatial and temporal uniformity. I am pleased to say that all of the initial design criteria were achieved, although the resulting system was a quite impractical monster, due mainly to a lack of engineering supervision and peer review.
 
However, it did all work, and my very first solo effort in writing a scientific paper described the results. I have just put a copy of the original on the publication page for download.
 
Reading it through, I am taken right back to the period more than forty years ago when the work was done. It was, in a sense, like Brunel’s Great Eastern steamship. A great behemoth, built for a particular purpose – one for which it was never used – totally impractical and very expensive to build. But it did work! I’m guessing that few if any CO2 TEA systems as good have ever been subsequently constructed, mainly because there just is no need for them.
 
It was a great learning experience though, and the paper describing it stands as a record of what was achieved. If there is anyone out there planning to build a high-stability CO2 TEA laser, I am available for consultancy…