2008 R&D 100 Winner
Phase-measuring interferometry has been the industry standard for measuring precision optics for the last 25 years, but modern computer numerically controlled (CNC) machinery has greatly expanded the variety of parts that can be produced, and a sizable percentage of the optics made today cannot undergo metrology testing for lack of tools.
To keep pace with ever more stringent accuracy requirements of modern optics manufacturing, QED Technologies, Rochester, N.Y., has developed the Subaperture Stitching Interferometer for Aspheres (SSI-A), a six-axis, computer-controlled interferometric workstation that marks a first in the optics industry. It is the first automated metrology device to profile both spherical (including large clear aperture and high numerical aperture) and aspherical optics. The SSI-A can profile up to 280-mm diameter optics and aspheric surfaces up to 100 waves of departure.
The system begins by locating a central null, or reference location. Then SSI-A builds a lattice of subaperture measurements which it connects, or stitches, to build a full aperture through the use of algorithms. The final result offers marked improvement over the use of null lenses.
Technology
Six-axis, computer-controlled interferometric workstation
Developer
QED Technologies
