Fig. 1. Schematic diagram of common-path interference phase microscopy. (a) On-axis interference;(b) micro off-axis interference; (c) off-axis interference

Fig. 2. Diagram of experimental setup

Fig. 3. Off-axis interference image of plane wave and phase recovery results of Fourier transform. (a) Interferogram; (b) wrapped phase; (c) 3D phase distribution

Fig. 4. Phase recovery results of the three step phase shift norm method for plane wave under off-axis interference. (a)-(c) 1st, 2nd and 3rd interferograms; (d) wrapped phase; (e) 2D display of the unwrapped phase; (f) 3D phase distribution

Fig. 5. Light path diagrams of the object light and the reference light in BS2. (a) Path of on-axis; (b) path of off-axis

Fig. 6. Diagrams of the off-axis interference experiment and simulation of polystyrene sphere and phase recovery results based on Fourier transform. (a)-(c) Experimental interferogram, wrapped phase and 3D phase distribution of polystyrene sphere; (d)-(f) simulation interferogram, wrapped phase and 3D phase distribution of polystyrene sphere

Fig. 7. Phase gradient diagrams of polystyrene sphere. (a) Experimental phase gradient map; (b) experimental phase gradient distribution curve; (c) simulated phase gradient map; (d) simulated phase gradient distribution curve