What was your first encounter with lasers?
As an undergrad in 1964, I had an interview at a little company in Mountain View, California, called Spectra-Physics. Nobody was in the entry room, so I sat and waited for half an hour until I heard people yelling and then I walked through to the back. Earl Bell greeted me and said “Let me show you a laser.” He had just built the first ionised-gas laser. I was fascinated. I became employee 13 and worked there for a year.
How did your laser work lead you to the hunt for gravitational waves?
In 1988, I was visiting the Joint Institute for Laboratory Astrophysics in Boulder, Colorado, when Pete Bender showed me his plans to detect gravitational waves in space using extremely stable and precise lasers. The plan required three satellites orbiting the sun in a triangular formation. The idea was that light from a laser in one satellite would be split into two beams, then each of these beams would travel a million kilometres to one of the other satellites and bounce back. If gravitational waves – tiny ripples in space-time – passed through the region, we would see signs of them when the returning light beams recombined. I had co-invented a laser of the kind that Pete needed, so I said we could probably make one for him. But that satellite system, now called the Laser Interferometer Space Antenna (LISA), still hasn’t been built.
So how did you get involved with the Laser …
More on these topics: