Technical feasibility of figuring optical surfaces by ion polishing

Area of Science:

• Materials Science
• Optical Engineering
• Surface Science

Background:

• Traditional methods for figuring optical surfaces can be labor-intensive.
• Achieving ultra-smooth optical surfaces is critical for high-performance optics.

Purpose of the Study:

• To describe and evaluate ion polishing for fabricating optical surfaces.
• To assess the effectiveness of ion polishing on various substrate materials.

Main Methods:

• Ion polishing using argon (Ar+) and xenon (Xe+) ions at specific energies.
• Characterization of optical surfaces using optical scatter measurements.
• Measurement of root-mean-square (rms) surface error.

Main Results:

• Sputtering yields determined for fused silica, ULE, and Cer-Vit.
• Optical scatter measured at 0.06% (lambda = 632.8 nm), comparable to conventional techniques.
• Reduction of rms surface error from 0.05lambda to 0.01lambda on a fused silica flat.

Conclusions:

• Ion polishing is a viable technique for high-precision optical surface figuring.
• The method offers comparable or superior surface quality to traditional lap techniques.
• The study provides a basis for designing ion polishing manufacturing facilities.