Transport of intensity equation (TIE) has been a popular and convenient phase imaging method that retrieves phase profile from the measurement of intensity differentials. In this paper we demonstrate superresolution TIE phase imaging by using structured illumination. The intensity illumination pattern interplays with the phase gradient and generates a modulation signal that shifts the phase spectrum down from higher spatial frequency regions. In this way, previously missing high frequency components of the phase are detected with a low resolution camera.
© 2015 Optical Society of AmericaPDF Article