On the 16th May 1960, Theodore Maiman at the Hughes Research Lab in California fired up the first confirmed demonstration of a laser using a synthetic ruby. A few months later on 12th December and persuing a different line of research, Ali Javan at Bell Labs, showed the first helium-neon gas-discharge laser.
One of the key differences between the two versions, was that the latter could operate continuously and within 3 months Bell demonstrated a phone call between two handsets using a laser to transmit the modulated voice signal. One of the underlying building blocks for the telecommunications era had arrived (the other being the semi-conductor).
Einstein had originally theorised back in 1917 that it would be possible to excite atoms such that when electrons change state, light (photons) would be emitted with a predictable wavelength. However, it wasn’t until 1954 when Charles Townes and two colleagues James Gordon and Herbert Zeiger at Columbia University produced a similar effect for the first time using ammonia molecules and microwaves. Townes later shared the Nobel Prize for Physics with two Russian scientists, Aleksandr Prokhorov and Nicolay Basov who produced similar results in the same year.
However, this was a MASER which used microwaves rather than light and there were significant difficulties in getting the technique to work for the shorter wavelengths involved. Townes developed ideas for an “optical maser” but it was Gordon Gould, a student at Columbia who came up with name LASER – light amplification by stimulated emission of radiation.
2010 marks the 50th anniversary of the creation of the first lasers and there’s a little bit of celebration going on. The UK’s Institute of Engineering and Technology (IET) has a selection of articles in its monthly magazine. The first two, “The Laser Reaches 50” and “Ten Unexpected Uses for Lasers” are the most accessible (and formed the basis for this post). Over in North America, LaserFest celebrates all things laser.
Now, where’s my lightsaber…