High-resolution spectroscopy of rubidium atoms

With a linewidth-narrowed diode laser system oscillating at 780.1 nm, the hyperfine structures of the 85RbD2 line were observed extensively under various conditions. The results obtained with shielding of the geomagnetic field agree well with existing theory. It was also found that the hyperfine spectra are very sensitive to the geomagnetic field and that the sign of the resonance changes under the influences of the geomagnetic field and the change in laser power.