Measurement method and device for large-curvature-radius non-zero-digit interference based on virtual Newton's ring

The invention provides a measurement method and device for large-curvature-radius non-zero-digit interference based on a virtual Newton's ring. Circular carrier-frequency Newton's ring interferograms are converted into linear carrier-frequency interferograms via second-order polar coordinates, a low-frequency moire fringe graph after low-pass filtering is demodulated, wavefront differential data between a to-be-measured spherical surface and a standard spherical surface is extracted, and a calculation formula of the curvature radius is derived. On the basis of a model of a ZEMAX software based Fizeau spherical large-curvature-radium non-zero-digit detection system, a finite iteration method is used correct backhaul errors during Newton's ring interferogram collection in non-zero-digit detection. The Fizeau spherical large-curvature-radium non-zero-digit detection system is constructed, and verification for the spherical large-curvature-radium non-zero-digit measurement technology based on the virtual Newton's ring is completed.