New Developments in Laser Spectroscopy

During the last few years several new ideas have been born, and new spectroscopic techniques were developed which not only improve the spectral resolution and increase the sensitivity for investigating single atoms but which also allow several interesting experiments for testing fundamental concepts of physics. 

In the historical development of science, experimental progress in the accuracy of measurements have often brought about a refinement of theoretical models or even the introduction of new concepts [14.1]. Examples are A. Einstein s theory of special relativity based on the interferometric experiments of Michel son and Morley [14.2] M. Planck s introduction of quantum physics for the correct explanation of the measured spectral distribution of black-body radiation, the introduction of the concept of electron spin after the spectroscopic discovery of the fine structure in atomic spectra [14.3] or the test of quantum-electrodynamics by precision measurements of the Lamb shift [14.4]. 

In this chapter some of these new and exciting developments are presented. 

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