Visual Observation of Piezoelectric Modes

Abstract

The rotation of the optical index ellipsoid of piezoelectric crystals by an electric field has been widely used for the modulation of light. In particular, KDP and ADP crystals have found extensive use because of their large electro‐optical (Pockel) effect; whereas, quartz crystals have found no application for this purpose because of their low Pockel effect. This paper reports experiments in which the rotation of the index ellipsoid of a quartz crystal by the crystal's piezoelectric resonant modes has been used: (1) to modulate in amplitude a laser beam at a fixed frequency and (2) to trace the piezoelectric modes by mean of an X‐Y plotter.