Optical beamforming for ultrasonic phased arrays

This paper describes potentially low cost, lightweight, and compact optical beamforming techniques for ultrasonic phased arrays. The use of a pair of tiny stamp-size low cost nematic liquid crystal (NLC) 2-D optical array devices for the transducer control sites allows compact, low control power beamforming for large (i.e., >128 element) 2-D transducer arrays. 8eing able to control many elements (e.g. 512) in a 2-D format leads to higher resolution ultrasonic detection that can be very useful in certain imaging applications such as tumor detection in the medical profession and tiny crack detection in machine parts inspection. The optical method also provides a high degree of carrier tunability. Thus, compared to an all-electronic controller, the proposed optical method for ultrasonic arrays can be beneficial in certain scenarios where cost, power, tunability, remote control, and resolution are key issues