Suppression of piezoelectric vibration on Pockels crystal

In measurements of impulse voltages by a Pockels sensor, oscillatory components have been observed in the tail part of optical signals of Pockels sensor. In this paper, oscillatory components of Bi ₄ Ge ₃ O ₁₂ (BGO) Pockels crystals in various shapes are investigated. The tested BGO crystals are rectangular solids, a cylinder solid and tapered quadratic solid. The oscillatory components are derived from light output and frequency analysis is done. The frequency of oscillation on the rectangular crystals is lower than theoretical value and that of cylinder solid is the same with that of circumscribed rectangular solid. In the case of the tapered BGO crystal, it is possible to reduce oscillatory component by distributing piezoelectric vibration in broad frequency bandwidth.