The Optical Society Oral History Project Interview with ... - OSA

Interview with Dr. Anthony Siegman, May 5, 2008 20
figure, invented the microwave cavity and patented it with a patent in which the figures
look like what everybody knows in microwave textbooks, in standard electromagnetic
theory textbooks. And, of course, the Varian brothers and the Klystron, and Hewlett and
Packard. And Frederick Emmons Terman, who was a major seminal figure in all this.
And so I was in that milieu, or I was a descendant, if you like, of that Stanford ancestry,
or maybe an adopted child of it. At that point, Bell Labs had invented something called
mode locking, which is a way of generating ultra short pulses by having the signal that
runs around inside the laser cavity, instead of being a continuous signal going back and
forth, it becomes a very short pulse. This pulse goes around and around and this
generates a train of very short pulses, and those are very useful for communications and
measurement purposes, and have led to the whole field of ultra fast physics today. My
contribution to that topic came from my having taught a Fourier transform course, so that
I understood the time-frequency-bandwidth relationships of all this very clearly from
electrical engineering concepts. Those were fundamental EE concepts. And I was able,
together with a grad student named Dirk Kuizenga, to come up with a very simple
analysis and model that really, in a very simple way, predicted the properties of active
mode locking , the pulse widths that could be obtained, and how to design for them and
how they depended on this and that. This analysis, and experiments we did to confirm it,
achieved some notoriety. Its the Kuizenga-Siegman model of active mode locking.
And I became involved, along with a lot of other people, with a lot of chemists and
others who wanted to use those pulses to measure fast chemical reactions and physical