Fig. 1. (a) Basic scheme for the measurement of optical components using CMI; (b) photo of the experimental setup; (c) amplitude and (d) phase of the center part of the random phase plate reconstructed by ePIE. The scale bar of (c) is 0.198 mm.

Fig. 2. Flowchart of iterative process.

Fig. 3. (a) Photo of the plate glasses used in experiments; (b) diffraction pattern recorded by CCD; (c) phase map of plate glass obtained directly by phase subtraction. The section marked by the black dashed circle with a diameter of 79.1 mm is used for the analysis of PV and RMS. The constant phase slope is not removed for these calculations.

Fig. 4. Least-squares linear regressions of PV (a) and RMS (b) comparing the measurements from the CMI and Zygo interferometer.

Fig. 5. Phase maps of ten different plate glasses measured by CMI and inteferometer.

Fig. 6. (a) Photograph of an optical flat with PV = λ/20; phase maps of the optical flat, measured by the Zygo interferometer (b) and (c) by CMI. λ = 632.8 nm.