HIGH-ACCURACY KERR EFFECT MEASUREMENT TECHNIQUE

Apparatus and techniques are demonstrated which allow gas phase dc electro-optic Kerr effect measurements to be made with 0.1 % absolute accuracy and nanoradian sensitivity. Measurements of the electric-field-induced birefringence of a gas are calibrated against a liquid Kerr cell, which is in turn calibrated absolutely in situ. Some of the problems addressed in this work are control of stray birefringence in order to obtain an extinction ratio below 10(-10), a simple method for calibration of space charge effects in the CS2 reference Kerr cell, construction of electrodes with accurately calculable fields, and an investigation of the sources of systematic errors and drifts and means to eliminate them.