Collision-induced gain

We present a novel scheme for achieving gain based on the notion of inducing a transient electric dipole moment in long-lived atomic or molecular metastable states via collision processes. As specific applications of this concept, we determine the induced gain for the I2P1/2(5p5) → 2P3/2(5p5) and the He1S0(1s2s) → 1S0(1s2) transitions for the case in which radiation emission is initiated by collisions with a molecular dipole.