MODIFICATION OF A STRONG RESONANCE RADIATION POLARIZATION IN MEDIA WITH DOPPLER-BROADENED TRANSITIONS OF 0-]1-TYPES AND 1-]0-TYPES AND IN THE PRESENCE OF A DC ELECTRIC-FIELD

For atomic media with resonant Doppler-broadened transitions of J = 0 --> J' = 1 or J = 1 --> J' = 0 type and taking into account the relaxa tion due to depolarizing collisions, a theory of non-linear optical po larization phenomena in the presence of a Dc electric field is develop ed. The theory is valid in the case of both arbitrary resonance radiat ion intensity and arbitrary external Dc electric field spatial orienta tion. The intensity-dependent contributions to variation of radiation polarization are analysed in detail in the Doppler limit. Special atte ntion is paid to the case of linear polarization of incident radiation ; in this case as well as in the presence of a oc electric field, the Doppler-enhanced non-linear optical contributions determining the emer ging ellipticity and the rotation angle of polarization, respectively, are of the same order of magnitude (unlike the case of external magne tic field, in which the key effect is the rotation of polarization). I t is shown, however, that in the case of the strictly transverse geome try and if the angle between the electric field direction and the init ial polarization vector is equal to 45 degrees, the Doppler-enhanced n on-linear optical contribution to the rotation angle becomes anomalous ly small. The effect of the presence of a longitudinal component of el ectric field on the non-linear optical polarization phenomena is inves tigated. In addition, although in the case of a purely longitudinal ge ometry for the considered transitions the electric field effect on rad iation polarization modification is absent, some analytic results conc erning self-rotation and deformation of a polarization ellipse in the Doppler limit for an intense initially elliptically polarized radiatio n are also presented.