Investigation of atomic transitions of cesium in strong magnetic fields by an optical half-wavelength cell

It has been demonstrated that the use of the $\lambda/2$ method allows one to effectively investigate individual atomic levels of the $D_2$ line of Cs (with the most complicated spectrum among all alkali metals) in strong magnetic fields up to $7$ kG. The method is based on strong narrowing of the absorption spectrum (which provides sub-Doppler resolution) of a cesium-filled thin cell with the thickness $L$ equal to a half-wavelength ($L=\lambda/2$) of the laser radiation ($\lambda$ nm) resonant with the $D_2$ line. In particular, the $\lambda/2$ method has allowed us to resolve 16 atomic transitions (in two groups of eight atomic transitions each) and to determine their frequency positions, fixed (within each group) frequency slopes, the probability characteristics of the transitions, and other important characteristics of the hyperfine structure of Cs in the Paschen–Back regime. Possible applications are mentioned. Two theoretical models have been implemented. The values of the magnetic field have been indicated at which the models describe the experiment well.