Design of instruments for the measurement of large-size anamorphic optical components

摘要

As optical components become larger and more complex, it becomes more difficult to use traditional techniques for the measurement of figure accuracy. The Large Optics Diamond Turning Machine (LODTM) located at Lawrence Livermore National Laboratory and the Off Axis Generating Machine (OAGM 2500) located at Eastman Kodak Company are examples of surface generating machines capable of manufacturing optics for which there are no independent means of figure measurement. Consequently, the LODTM and the OAGM are provided with metrology capabilities to perform their own quality control. This situation violates the conventional quality control practice of independent part inspection. Independent part inspection can be achieved on the M60 Universal Coordinate Measuring Machine located at Martin Marietta Energy Systems Corporation. The M60 is capable of inspecting an anamorphic optic measuring two meters on the diagonal to an accuracy approaching one half of a wavelength RMS in the visible spectrum. The M60 represents the first in a class of large coordinate measuring machines providing greater accuracy and precision. This paper provides an overview of the design and accuracy achieved in the LODTM, OAGM, and M60. Applications and future potential are discussed.