Stitching interferometry of aspherical surfaces

Thomas Haensel; Andreas Nickel; Axel Schindler

doi:10.1117/12.450103

10 December 2001 Stitching interferometry of aspherical surfaces

Thomas Haensel, Andreas Nickel, Axel Schindler

Proceedings Volume 4449, Optical Metrology Roadmap for the Semiconductor, Optical, and Data Storage Industries II; (2001) https://doi.org/10.1117/12.450103
Event: International Symposium on Optical Science and Technology, 2001, San Diego, CA, United States

Abstract

Sub-aperture stitching interferometry (SASI) is an appropriate method to measure either large optical plane surface topologies or aspheres with strong deviation from the flatness with standard interferometers. Using SASI the surface shape is measured with a higher lateral resolution by multiple adjacent sub-aperture measurements with a sufficient overlap of the neighboring areas. In a second step, the total surface shape is composed with the help of a computer code by stitching the sub-aperture areas together. The overlap areas allow fitting. By means of a regression analysis, tilt and vertical displacement of adjacent areas are calculated and minimized. A confidence band calculated using a MATLAB based code describes the accuracy of the composition. The variance of this estimation is inverse proportional to the peak to valley value (PV) of the measured area and decreases with a 10-3 scaling of the width of the overlapping area. A statistical experimental design method is used to minimize the number of sub-apertures to be measured. The accuracy of the stitched total surface measurement can be increased with the help of model calculations by optimizing (i) the position of the sub-aperture, which was regarded as a standard, and (ii) the sequence of the stitched adjacent areas.

Citation Download Citation

Thomas Haensel, Andreas Nickel, and Axel Schindler "Stitching interferometry of aspherical surfaces", Proc. SPIE 4449, Optical Metrology Roadmap for the Semiconductor, Optical, and Data Storage Industries II, (10 December 2001); https://doi.org/10.1117/12.450103

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available