Improved technique for measuring full-field absolute phases in a common-path heterodyne interferometer

Abstract

When an asymmetric triangle voltage signal is applied to drive an electro-optic modulator, interference signals with two groups of periodic sinusoidal segments with different frequencies are obtained. An improved method is proposed to fit these two groups of segments, and their associated phases can be determined. The absolute phase can be obtained by subtracting the initial phase from the phases of these two groups. This technique is applied to all pixels, and the full-field absolute phase measurements can be achieved. The validity of this method is demonstrated. (c) 2010 Optical Society of America