Application of modified stimulated photon echo technique for measuring relaxation rates of orientation and alignment in an atomic gas

The phenomenon of modified stimulated photon echo is registered on two adjacent quantum transitions of 174Yb atoms. The experiments were performed in a rarefied atomic vapour of ytterbium, strongly diluted by the noble gas xenon. Light pulses of linear polarization with specially selected mutual orientations of the polarization vectors were used to excite the atoms, which made it possible to measure the relaxation rates of the orientation and alignment for a three times degenerated intermediate quantum level of 174Yb atoms. The method of modified stimulated photon echo is compared to the method of conventional stimulated photon echo.