Method of Producing Transducers with Phase, Area & Depth Controlled Polarization: 3,950,659

A method for obtaining controlled depth, controlled area, and controlled phase polarization of a piezoelectric transducer element. A controlled phase bias voltage is applied to two generally opposing surfaces of the transducer element, and heat is then applied in a pulsed fashion to one of the two surfaces. By properly coordinating the phase of the bias voltage and the pulsed heating of the one surface, discrete layers of polarization may be created between the two surfaces, the phase, area and depth of the discrete layers being accurately controllable.