Optical frequency combs from mode-locked femtosecond lasers have revolutionized the art of measuring the frequency of light. The coherent nature of short pulses has led to a remarkable union of the two previously quite distinct fields of ultrafast science and precision spectroscopy. On one hand side frequency combs can conveniently link optical and microwave frequencies, and they provide the long missing clockwork for optical atomic clocks. So far no fundamental limit of the accuracy of frequency combs has been discovered.
© 2006 Optical Society of AmericaPDF Article