Electromagnetically induced transparency with a standing-wave drive in thefrequency up-conversion regime - art. no. 033802

We study electromagnetically induced transparency for a probe traveling-wav e (TW) laser field in closed Doppler-broadened three-level systems driven b y a standing-wave (SW) laser field of moderate intensity (its Rabi frequenc ies are smaller than the Doppler width of the driven transition). We show t hat probe windows of transparency occur for values of the probe to drive fi eld frequency ratio R close to half-integer values. For optical transitions and typical values of Doppler broadening for atoms in a vapor cell, we sho w that for R > 1 a SW drive field is appreciably more efficient than a TW d rive in inducing probe transparency. As examples, we consider parameters fo r real cascade schemes in barium atoms with R approximate to 1.5 and in ber yllium atoms with R approximate to 3.5 showing that probe transmission valu es well above 50% are possible for conditions in which it is almost negligi ble either without driving field or with only one of the TW components of t he drive. We show that a strongly asymmetric drive having two TW components with unequal intensities is even more efficient than a symmetric SW drive in inducing probe transparency. The case of arbitrary probe intensity is al so considered.