Piezoelectric ringing

A dramatic demonstration of the low piezoelectric ringing in the miniaturized LN PC is shown in figure below where the miniaturized LN PC is directly compared to the block LN PC and the RTP PC. Both PCs were switched with the homemade PC driver. The intensity transmitted through the conventional block LN PC varies greatly and it does not follow the decay of the applied high voltage pulse. Whereas the pulse switched by miniaturized LN PC cleanly follow s the applied high voltage pulse, which is similar to that of the RTP PC. The difference is thought to be due to the different intensity of piezoelectric ringing in the crystals. For a crystal with large piezoelectric effects, when it subjected to high voltage pulses, piezoelectric effects can give rise to acoustic waves in the crystal, the acoustic waves continue to modulate the crystal birefringence through the elasto-optic effect long after the high voltage pulse is applied. As a result, there was still high intensity transmitted signals long after the voltage dropped to zero. Undoubtedly, the piezoelectric ringing effects will impair the performance of the PC. From the figure below, it can be derived that the block LN PC suffers enormously from piezoelectric ringing, while the piezoelectric ringing in the miniaturized LN PC is similar to that of the RTP PC and is very weak. RTP crystals are well known to be free from acoustic ringing, thus it is deduced that the piezoelectric ringing in the miniaturized LN PC is negligible.

Qualitative comparison of piezoelectric ringing in miniature LN, block LN and RTP