Nanometer resolution with dammann grating of 50Ip/mm

摘要

A grating interferometer (GI) system based on transverse Zeeman laser is proposed in this paper. Dammann grating is introduced as a measurement element as well as beam splitter in this system. Nanometer calibration between GI and a differential dual-frequency interferometer (DDFI) is also described in detail. The result of the experiment confirms its good capability of resisting environment disturbance with a resolution in the order of nanometer by means of heterodyne signal processing method. Its measurement accuracy reaches +-25nm under laboratory condition.