"Femtosecond laser frequency combs and their use in precision spectroscopy,
low noise frequency synthesis, and optical clocks"
Scott A. Diddams
NIST - Boulder
Wednesday, March 15, 2006 -11 AM - 12:00 Noon in 375 Le Conte Hall
Abstract
A femtosecond laser frequency comb (FLFC) is the boardband, evenly-spaced array of
optical frequencies present in the output of a femtosecond mode-locked laser. Such frequency combs have been found in
widespread use in optical frequency metrology and optical atomic clocks,.
and now their role in other precision measurements is expanding. Beyond a general overview of FLFC's
in this talk I will cover the following topics: (1) Recent advances in the generation of octave -spanning combs
directly from Ti: sapphire lasers as well as our efforts to produce more energy efficient and robust frequency combs
that should be useful for transportable instruments.
(2) Highly dispersive elements, like the soc alled VIPA (Virtually Imaged Phased Array), that
now permit the spatial separation of the frequency comb elements with a resolution approaching 1 GHz.
This provides access to the individual comb elements and opens new possibilities in arbitrary waveform generation,
spectroscopic sensing, and secure optical communications. (3) The use of optical frequency combs for direct atomic spectroscopy,
as well as the comparison of microwave and optical frequency standards with uncertainty below 1e-15.
