Enhanced mid-spatial frequency error suppression through multi-directional randomized path superposition processing.

Area of Science:

• Optical Engineering
• Surface Metrology
• Manufacturing Processes

Background:

• Mid-spatial frequency (MSF) errors degrade optical system performance.
• Regular processing paths are a primary source of MSF errors.
• Current pseudo-random paths reduce MSF but retain directional artifacts.

Purpose of the Study:

• Introduce a novel tree-growth randomized path generation (TRPG) algorithm.
• Develop a multi-directional randomized path (MDRP) superposition method.
• Enhance path disorder to suppress MSF errors more effectively.

Main Methods:

• Emulating natural tree branching for TRPG.
• Superposing multiple randomized paths with incorporated random directionality (MDRP).
• Comparing MDRP with single-pass random path and fixed-direction random path (FDRP) superposition.

Main Results:

• Single-pass random path and FDRP superposition processing result in significant characteristic frequencies.
• MDRP superposition processing shows no observable characteristic frequencies.
• MDRP processing demonstrates superior suppression of MSF errors.

Conclusions:

• The proposed TRPG algorithm and MDRP method significantly reduce MSF errors.
• Random directionality in path superposition is crucial for effective MSF error suppression.
• MDRP offers a substantial advantage over existing methods for improving optical surface quality.