We show that, in an optically pumped resonant $J=1\ensuremath{\rightarrow}{J}^{\ensuremath{'}}=0$ laser, a gain anisotropy is induced by a linearly polarized coherent pump beam that can be balanced or countered by
x-
y cavity-loss anisotropies, leading to switching between the
x and
y linearly polarized states of the generated laser field as the laser intensity is increased. This switching is not brought about by selection of the mode with the maximum emission intensity. A domain of bistability between the two linearly polarized states is found, whose width depends on the value of the decay rate of the two photon coherence induced among the sublevels of the
J=1 level manifold. Differently from the incoherently pumped $J=1\ensuremath{\rightarrow}{J}^{\ensuremath{'}}=0$ laser, the decay rate for the magnetic dipole in that manifold has no influence on the polarization of the emission.
A theoretical investigation of the change in polarization of ultrashort pulses of light near the two-photon resonance is carried out. A strong wave of circular polarization in the medium induces optical anisotropy which affects the change in weak probe-wave polarization. It is shown, that owing to an interaction transient, the probe-wave polarization becomes elliptical whose parameters change depending on time and position. This leads, in turn, to oscillation dependence of the rotated component of the probe field amplitude on the pumping energy, and the length and density of the resonant medium.
Abstract A collision-induced photon echo (PE) was formed at the 174 Yb (6s 2 ) 1 S 0 —(6s6p) 3 P 1 transition by two resonant radiation pulses polarized linearly and mutually orthogonally. The noble gases He, Ne, Ar, Kr and Xe were used as collision partners for excited 174 Yb atoms. The nonmonotonous decay kinetics of collision-induced PE was detected. The ordinary PE formed by identical linear polarization pulses at the same experimental conditions showed a monotonous decay for the time delays between 80 and 300 ns. The anisotropy parameters for the collisions of 174 Yb atoms with Ne, Ar, Kr and Xe atoms increase with the buffer atom mass and are between 15% and 20% of the corresponding homogeneous line broadening values.