Superelastic scattering with imperfect laser polarization

The formalism applied to superelastic electron scattering from laser-excite d atoms has to date assumed perfect polarization of the laser light. We con sider the effects of imperfect polarization, deriving an expression for the superelastic scattering rate from target atoms optically pumped with ellip tically polarized light, and show how imperfect polarization effects can be measured and minimized under experimental conditions. In particular, we fi nd that in measuring the scattering for linearly polarized light with a sma ll circular component. the errors are proportional to the undesired circula r polarization component and to (P) over bar(3), the scattering sensitivity to circular light. We also present in detail a polarizer design which gene rates both linear and circular polarizations, allowing measurement of all s cattering polarization sensitivities without requiring interchange of optic al elements.