Design of double-beam interferometer for detecting piezoelectric strain of thin film

Abstract

In order to measure micro-strain of piezoelectric thin film under action of electric field and avoiding the impact of substrate bending effect, a double-beam interferometer is designed. The objective of high stability and high resolution is achieved through feedback control and phase-locking detection technique. The minimum detectable strain is as small as 0.001nm. With measurement and data processing are controlled by a computer, the system has the advantages of convenience, fast measurement speed and high accuracy.