On the light shift in optical pumping of rubidium 87: the techniques of "separated" and "integrated" hyperfine filtering

Results of measurements of light shifts observed in the optical pumping of rubidium 87 by means of electrodeless rubidium lamps are reported. The techniques of separated and integrated hyperfine filtering by means of the rubidium 85 isotope are compared. A phenomenological theory which explains qualitatively the results obtained is presented. Conclusions are drawn in relation to the use of either technique in passive rubidium frequency standards.