Observation of a Laser-induced Dipole-quadrupole Collision

Experimental observation of a laser-induced dipole-quadrupole collision between Sr and Ca is reported. The laser-induced collision cross section peaks at an applied photon energy equal to the energy defect of the initial and final states of the infinitely separated atoms. A cross section of 3 x 10(-14) cm(2) was induced at a laser-power density of 7 x 10(9) W/cm(2); the linewidth was 20 cm(-1).