Nobel Lecture: Passion for precision^*

Figure 1

(Color) The relative accuracy in optical spectroscopy of atomic hydrogen is charted over eight decades. Major barriers have been overcome in the early 1970s with the advent of Doppler-free laser spectroscopy and in the early 1990s with the introduction of optical frequency measurements. The accuracy of such measurement will soon be limited by the performance of cesium atomic clocks. Dramatic future advances are expected from the development of optical atomic clocks.

Figure 2

(Color) Scheme of femtosecond laser frequency comb synthesizer.

Figure 3

(Color) Interference fringes between two white light pulses (6).