The use of highly monochromatic light permits the selective excitation of atoms in vapors if excitation and detection of the fluorescence is carried out collinearly. The atoms capable of absorbing light then form an atomic beam of well-defined velocity along the direction of the laser beam, but no velocity selection occurs perpendicular to it. The potential of the technique for Doppler-free atomic spectroscopy and for the study of excited atom collisions is demonstrated by using the Na D1 line as an example.
© 1984 Optical Society of America
T. Meier and H. A. Schuessler, "Laser-induced fluorescence line narrowing in atomic vapors," J. Opt. Soc. Am. B 1, 161-163 (1984)