Structure optimization and fabricating capability analysis of an ion-beam machine for a subnanometer optical surface

Area of Science:

• Optical Engineering
• Materials Science
• Precision Engineering

Background:

• High-performance optical systems demand ultra-precise and ultrasmooth surfaces.
• Ion-Beam Figuring (IBF) is a deterministic method for precision optical finishing.
• IBF performance hinges on machine dynamic performance and ion-beam stability.

Purpose of the Study:

• To investigate the influence of IBF machine dynamic performance on optical surface figuring.
• To optimize the structure of a quick-response platform for improved dynamic performance.
• To achieve uniform convergence of surface errors across all spatial frequencies.

Main Methods:

• Structural optimization of a quick-response platform based on ultra-precise surface error fabrication capabilities.
• Analysis of dynamic performance limitations imposed by the motion system's acceleration and velocity.
• Manufacturing experiments on a fused silica spherical concave surface using the optimized IBF machine.

Main Results:

• The optimized IBF machine effectively corrected figure errors and enhanced surface quality.
• Uniform convergence of surface errors across all spatial frequencies was achieved.
• Final surface error reduction reached 0.368 nm RMS, 0.204 nm RMS, and 0.087 nm RMS.

Conclusions:

• The newly designed IBF machine's dynamic performance meets stringent requirements for sub-nanometer optical surface fabrication.
• Optimized dynamic performance is crucial for deterministic error correction in IBF.
• The study demonstrates effective sub-nanometer optical surface finishing using advanced IBF technology.