By applying Doppler-free saturated absorption spectroscopy in the regime of high integrated sample absorption, high-contrast Doppler-free laser transmission signals can be obtained as demonstrated in experiments on the sodium D lines. Natural linewidth background-free signals are observed.
© 1986 Optical Society of America
S. Svanberg, G.-Y. Yan, T. P. Duffey, and A. L. Schawlow, "High-contrast Doppler-free transmission spectroscopy," Opt. Lett. 11, 138-140 (1986)