Stark-induced three-wave mixing in molecular gases - Part I: Theory

Application of dc electric field to a gaseous system destroys the basic inversion symmetry and allows three-wave mixing processes to occur. A theoretical derivation of this effect under conditions of resonantly enhanced nonlinearities is given for a three-level system. Calculations are presented for mixing of a CO
2
laser with 4-GHz microwaves in the molecule NH
2
D, producing single lower sideband radiation.