Phase-sensitive electric modulation of photoluminescence upon bichromatic excitation of atoms

A new type of modulation of the photoluminescence intensity of atoms excited by a bichromatic laser radiation with the frequency ratio 1:2 is proposed and analysed. The modulation is produced by alternating electric field acting on atoms and occurs due to the quantum interference of the amplitudes of two excitation channels of an atom, which proves to be possible because the applied electric field removes the parity selection rule for one of the excitation channels. An important feature of this process is the dependence of photoluminescence on the phase difference of monochromatic components of exciting radiation. The calculation was performed for an alkali metal atom excited at the s–s transition taking the saturation effect into account.