Time efficient method for defocus error compensation in tomographic phase microscopy

Abstract

We present a holographic method for defocus error compensation in tomographic phase microscopy, which enables high quality reconstruction in the presence of a meaningful run-out error of the measurement system. The proposed method involves indirect determination of the sample displacement from the in-focus plane. The sought quantity is deduced from the transverse movement of the rotating sample, which can be determined with high precision using correlation-based techniques. The proposed solution features improved accuracy and reduced computation time compared to the conventional autofocusing-based approach. The validity of the concept is experimentally demonstrated by tomographic reconstruction of an optical microtip.