Interference microscopy using spatial Fourier filtering with a vortex phase element leads to interference fringes that are spirals rather than closed rings. Depressions and elevations in the optical thickness of the sample can be distinguished immediately by the sense of rotation of the spirals. This property allows an unambiguous reconstruction of the object's phase profile from one single interferogram. We investigate the theoretical background of "spiral interferometry" and suggest various demodulation techniques based on the processing of one single interferogram or multiple interferograms.
© 2006 Optical Society of America
Original Manuscript: July 27, 2005
Revised Manuscript: November 25, 2005
Manuscript Accepted: December 3, 2005
Vol. 1, Iss. 7 Virtual Journal for Biomedical Optics
Alexander Jesacher, Severin Fürhapter, Stefan Bernet, and Monika Ritsch-Marte, "Spiral interferogram analysis," J. Opt. Soc. Am. A 23, 1400-1409 (2006)