Controlling mid-spatial frequency errors in magnetorheological jet polishing with a simple vertical model.

Area of Science:

• Optics and Photonics
• Materials Science and Engineering
• Manufacturing and Industrial Engineering

Background:

• Mid-spatial frequency (MSF) errors are an inherent challenge in magnetorheological jet polishing (MJP).
• Controlling these errors is crucial for achieving high-precision optical surfaces.

Purpose of the Study:

• To develop and validate methods for suppressing MSF errors during MJP.
• To analyze the relationship between surface errors and power spectral density (PSD).

Main Methods:

• Analysis of MSF errors and their relation to surface power spectral density.
• Implementation of a cut-off frequency and a tailored removal function.
• Design of a uniform polishing path and a weighted iterative algorithm for dwell time mapping.
• Utilization of the duplication ratio to manage surface nonuniformity.

Main Results:

• Significant reduction in surface roughness: peak-to-valley (P-V) from 0.384λ to 0.054λ and root mean square (RMS) from 0.077λ to 0.007λ (λ=632.8 nm).
• Achieved smooth power spectral density (PSD) curves with low and uniform distribution.
• Experimental validation of the developed control strategies in an MJP process.

Conclusions:

• The proposed methods effectively restrain MSF errors in magnetorheological jet polishing.
• The study demonstrates a viable approach for achieving ultra-smooth surfaces with controlled MSF characteristics.
• Optimized MJP processes can yield significant improvements in surface quality for demanding applications.