Signal processing method and apparatus for use in real-time subnanometer scale position measurements with the aid of probing sensors and beams scanning periodically undulating surfaces such as gratings and diffraction patterns generated thereby, and the like

摘要

An improved signal processing method and apparatus are presented for use in real-time sub-nanometer scale position measurements with the aid of probing sensors and/or beams scanning periodically undulating surfaces such as a grating and diffraction patterns generated thereby, and the like, enabling greater sub-nanometer precision, higher stage scanner movement speeds, and simultaneous high accuracy and top speed measuring capabilities.