DIFFERENTIAL-MODE ATOMIC POLARIMETRY WITH PULSED LASERS - HIGH-PRECISION ZERO ADJUSTMENT

We discuss the precise zero adjustment of a balanced differential-mode polarimeter containing an atomic sample for dark-field detection of a small atomic parity-violation anisotropy odd under reversal of an app lied E field. Our sample is endowed within E-even parity-conserving an isotropy, possibly large, but oriented to produce no imbalance. An imb alance arises both from defects in the preparation of the sample and f rom small probe-beam anisotropies coupling with those of the sample. A n adjustment procedure allows identification and reduction of each def ect. The residual E-even imbalance is maintained at the noise level by active compensation. (C) 1997 Optical Society of America.