A new high-precision device for one-dimensional grating period measurement

This paper introduces a new device for one-dimensional grating period measurement with high accuracy. The scheme includes two subsystems: a grating interferometer and a laser interferometer. As the grating moves, the grating interferometer obtains periodic signal related to the grating period, while the laser interferometer measures the displacement simultaneously. The grating period is then obtained through data processing and least-square-fitting. Most of the grating period measurement devices have scattered structures, poor stability, which could be affected by the environment easily. In order to overcome this shortcoming, we adopt the structure of glued prisms, which is compact, and will significantly improve the stability of the system. Thus, the scheme has advantages in measurement accuracy as well as resolution. The system benefits from simple structure and cheap components, which can be widely used in grating period measurement technology.