David Lockwood's memories from the 1960s
David says, "The first three photos are from my MSc Thesis completed in 1964. The experiments in the Thesis were aimed at examining the effects of sound waves on colloids, which are very small particles that are found in clays for example (for more details see page 181 of http://www.cap.ca/PiC-PaC/static/downloads/1efdc1f3784b85c1a1b33e396b91ee8aef207...). In fact, I was looking at nanoparticles of matter, which preceded the emergence of nanotechnology as a field of research by more than two decades. I needed a suitable light source to probe the alignment of the nanoparticles in the ultrasonic sound field. At that time the laser had just been invented and I realized that this was the ideal light source for my experiment. I then proceeded to construct the first home-built laser in New Zealand. This laser - a He-Ne continuous-wave gas laser - operated at 632.8 nm (in the red). This laser, over a metre long, is shown in the black-and-white photo. There were lot of problems to be overcome, but eventually, with invaluable help from Dr. Tom Seed (my MSc supervisor) and Dr. Rod Syme, I had it working. The colour photos show the complete experimental system, including the horn-shaped acoustic chamber in front and the operating laser in the rear, and a typical optical diffraction pattern obtained from the original red laser beam arising from a grating structure formed by the alignment of a colloid under the influence of a travelling sound wave.
"The other two photos are from my PhD Thesis completed in 1969 under the supervision of Professor Alister McLellan. This thesis is concerned with setting up the first computer-controlled laser Raman spectroscopy equipment (shown in one photo - that's me wearing the laser safety goggles) in New Zealand and using it to measure the vibrational spectrum of novel materials grown in the Physics Department. It is very likely that my setup was also the first in the Southern Hemisphere. In contrast to the He-Ne laser I developed for my MSc thesis, the laser I used was one of the first commercial lasers - an argon gas laser (shown in the other photo) that required frequent painstaking maintenance. This was because the He-Ne gas laser did not produce enough power for my experiments.
"Incidentally, the specially chosen date when I completed my PhD Thesis was 21 July 1969, which marked the day (20 July 1969 in the USA) that Neil Armstrong was the first human being to walk on the moon. It was my great fortune and a pleasure for me to later meet Armstrong following a lecture he gave at the University of Edinburgh on 10 March 1972."