Photograph of argon gas laser
A scanned copy of a black and white photograph of the argon gas laser used by David Lockwood in his PhD research at the University of Canterbury. David says, "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 that required frequent painstaking maintenance. This was because the He-Ne gas laser did not produce enough power for my experiments".