Single-exposure polarization phase-shifting interferometer using an azo-polymer orientation array

•A single-exposure polarization phase-shifting interferometer is presented.•The azo-polymer orientation array is fabricated for the interferometer.•Experimental verification shows the effectiveness of the interferometer.•A new application of azo-polymer in phase-shifting interferometer is demonstrated.

We propose a single-exposure polarization phase-shifting interferometer based on a beam-splitting method using an azo-polymer orientation array, which is prepared from an ordinary azo-polymer film with photo-induced optical anisotropy. The azo-polymer orientation array gives a four-step phase shift on the interferogram, from which phase differences between the orthogonal polarized reference and object beam can be calculated. Experimental results are provided to verify the feasibility of the proposed interferometer. The azo-polymer orientation array is easy to fabricate, making this method convenient and low-cost.