Polar-coordinate-based Data Analysis Scheme for High-Voltage Measurement System Using the Pockels Electro-Optic Effect

A voltage measurement system based on the Pockels electro-optic effect typically has, due to a half-wave voltage V-pi of a Pockels cell, a limitation on the unambiguous measurable range. To overcome such a limitation, we develop a polar-coordinate-based data analysis scheme with a simultaneous measurement of cos (pi V/V-pi) and sin (pi V/V-pi), where V is the voltage the Pockels cell experiences, i.e., the voltage we wish to measure. The developed data analysis scheme also corrects, without knowledge of V-pi, a misalignment of the Pockels cell and an imbalanced transmittance of a beam splitter between the horizontal and vertical components of the polarized laser beam. Thus, increased accuracy of not only the V-pi measurement during calibration procedure but also the voltage measurement itself is also achieved.