Investigation of piezoelectric ringing effects in Pockels cells based on beta barium borate crystals

Abstract

A detailed investigation of piezoelectric ringing and resonance effects in beta barium borate (BBO) crystal based Pockels cells in a pulse picker device is presented. Measurements mapping piezoelectric oscillation amplitude distribution in the aperture of BBO crystal were also performed. It was determined that in BBO Pockels cells due to piezoelectric ringing and related effects the optical contrast ratio is reduced by 6 – 70 times at certain (resonance) frequencies. Moreover, we demonstrate that in our pulse picker device which uses a special sequence of control pulses (regeneration method) for the Pockels cell, at certain high voltage control signal durations piezoelectric oscillations can be suppressed which significantly improves performance of Pockels cell based laser pulse picker device at resonance frequencies: in such cases the optical contrast ratio is stable and higher than 1000:1. Numerical simulation results support the experimental data.