Laser in the axial electric field as a tool to search for P-, T-   invariance violation
  We consider rotation of polarization plane of the laser light when a gas laser is placed in a longitudinal electric field (10~kV/cm). It is shown that residual anisotropy of the laser cavity 10^{-6} and the sensitivity to the angle of polarization plane rotation about 10^{-11} -10^{-12} rad allows one to measure an electron EDM with the sensitivity about 10^{-30} e cm. 
V. G. Baryshevsky, S. L. Cherkas and D. N. Matsukevich