Atomic beam measurements of the $^{133}$Cs $7\mbox{d} ^2\mbox{D}_j$ hyperfine structure

The hyperfine structures of the $7\mbox{d} ^2\mbox{D}_{3/2}$ and $7\mbox{d} ^2\mbox{D}_{5/2}$ states of cesium are studied using two-color, fluorescence spectroscopy in an atomic beam. Two single-mode external-cavity diode lasers probe the $7\mbox{d} ^2\mbox{D}_j$ states through two-color resonant excitation. One laser is locked to the $6\mbox{s} ^2\mbox{S}_{1/2} (\mbox{F}) \rightarrow 6\mbox{p} ^2\mbox{P}_{3/2} (\mbox{F}')$ transition using a servo-feedback circuit; optical pumping of the ground state is minimized through electro-optic modulation of this laser. The second laser is scanned over the $6\mbox{p} ^2\mbox{P}_{3/2} (\mbox{F}') \rightarrow 7\mbox{d} ^2\mbox{D}_j (\mbox{F}'')$ hyperfine manifolds. High resolution is achieved by referencing the frequency scale of the second laser directly to the $^{87}$Rb ground state hyperfine transition using a radio-frequency modulation technique.