An interference system has been studied and its ability in measuring surface profiles is shown. The precision of the interference system is easily up to 0.05 μm, and its measure-ment range is independent of coherence length of source. In this system, a crating is used, and its spatial period and ruled length respectively influence the precision and measurement range of the system. If a long and fine grating is used, both high precision and large measurement range can be obtained at the same time.
C. W. Wu,
S. T. Lu,
"Surface Profile Measurement Using Optical Grating", Proc. SPIE 0802, In-Process Optical Metrology for Precision Machining, (1 January 1987); doi: 10.1117/12.967112; https://doi.org/10.1117/12.967112