**4.1 Displacement measurement of cantilever by phase-shifting digital holographic interferometry**

As an experiment, the deflection of a cantilever is also measured using the optical system shown in Figure 1. As a specimen, a same size cantilever shown in Figure 2 is also analyzed. In this experiment, a fixed reference plate is set at 1.3 mm behind the cantilever to check spatial resolution, as shown in Figure 1.

The reconstructed images (the intensity distribution, i.e., the amplitude squared) and the phase distributions are obtained from the holograms with 960 x 960 pixels before and after deformation. The reconstructed image before deformation is shown in Figure 9(a). The phase-difference distribution before and after deformation, that is, the out-of-plane displacement distribution is shown in Figure 10(a).

Fig. 9. Reconstructed image obtained by Windowed PSDH

Fig. 10. Phase difference distribution obtained by Windowed PSDH
