Compact version of atomic clock based on radio optical end state resonance

The characteristics of the compact atomic clock are investigated, based on two laser pumping quantum magnetometers scheme, one of which is a low-frequency spin generator, another is a radiospectrometer based unit locked to the magnetically-independent microwave transition resonance line. Pumping laser is tuned to the head doublet D2 line of rubidium 87 atoms, placed into the anti-relaxation coated cell. The use of the one optical channel for two quantum magnetometers allowed to realize the high signals correlation and the minimum data processing errors level. The difference of synchronously recorded magnetometer signals is processed to determine the Allan variance as a averaging time function. This parameter essentially depends on the pumping radiation circular polarization sign. The dependence is not observed in atomic clock based on buffer gas cell. In this case, the unit operates on the long-wavelength component of the electric dipole transition only, when the largest number of atoms interacts with the pump light. The laser tuning to the D2 line short-wavelength component does not leads to the positive effect. This result exists due to the decreasing of the working substance atoms, because the atoms pumping in the laser light non-interacted state takes place.