Abstract

Recently, it has been demonstrated¹ that an optical pumping process could lead to sub-Doppler features in the transmission spectrum of a thin (L = 10–100 μm) cell. Indeed, when the cell is highly anisotropic (thickness << beam diameter), the optical pumping (e.g., transfer to a transparent hyperfine sublevel) is efficient only for atoms with a sufficiently long free path, i.e., atoms with a small normal velocity, thus increasing the transmission on line center.

© 1998 Optical Society of America