A Differential Phase-Modulated Interferometer with Rotational Error Compensation for Precision Displacement Measurement

In this paper, a differential phase-modulated interferometer (DPMI) is proposed to compensate for the rotational error precision displacement measurement. DPMI, reference sharing same arm with measurement constructed. Using two interferometers differentially measure displacement, unbalanced environmental disturbance on can be minimized. An integrated 2 × array photodetector (APD) adopted in DPMI. Based APD wavefront sensing (DWS) technology, rotation angle detected and compensated. Therefore, without achieved. Three confirmatory experiments were performed, experimental results show that maximum drift reduced from 902.9 nm 16.3 100 min stability test, standard deviations between pitch yaw angles obtained by DPMI Renishaw are 1.68 10?5° 1.86 10?5°, respectively, deviation result of stage positioning before after compensation 5.207 ?m about 0.719 ?m.