Control of Atomic Collisions by Laser Polarization

Atomic collision pairs in a light field form a microscopic interferometer. The light acts as the beam splitter and controls at the same time the amplitudes and phases of the interfering waves. We demonstrate the complete tunability using linear and elliptic polarization.

Figure 1

(a) The potential curves of the NaNe collisional molecule in the light field. Only the ${}^2\Sigma$ states (heavy lines) participate in the present process. (b) The classical trajectories with the transition points and the Condon vectors.

Figure 2

(a) The linear polarization directions $\mathbf{E}$ used in the experiment and the Condon vectors ${\mathbf{r}}_1$ and ${\mathbf{r}}_2$. The relative velocity direction before the collision is along the horizontal axis. (b) The experimental differential cross sections as a function of the scattering angle $\theta$, multiplied by $\sin (\theta )$. Velocity range $1100–1250\mathrm{m}/\mathrm{s}$. (c) The corresponding theoretical differential cross sections.

Figure 3

(a) The elliptic polarization and the Condon vectors for the indicated value of the control parameter. The relative velocity direction before the collision is along the horizontal axis. (b) The experimental differential cross sections as a function of the scattering angle $\theta$, multiplied by $\sin (\theta )$. Velocity range $1150–1300\mathrm{m}/\mathrm{s}$. The positions of the interference maxima were obtained from a polynomial fit. (c) The corresponding theoretical differential cross sections.