Improving diameter measurement from Fraunhofer diffraction with fringe segment splicing.

Area of Science:

• Optics and Photonics
• Metrology and Measurement Science

Background:

• Fraunhofer diffraction is a widely used technique for measuring thin filament diameters.
• Practical applications are limited by system imperfections, leading to reduced measurement resolution.
• Existing methods struggle with accuracy due to factors like small angle approximation and sensor thresholds.

Purpose of the Study:

• To propose and validate a novel method for improving diameter measurements using Fraunhofer diffraction.
• To address the resolution degradation caused by real-world system imperfections.
• To enhance the accuracy of thin filament diameter determination.

Main Methods:

• Development of a fringe segment splicing technique for Fraunhofer diffraction patterns.
• Selection of fringe segments from real diffraction patterns to reconstruct ideal fringes.
• Solving the diameter measurement problem in the spatial frequency domain using reconstructed ideal fringes.

Main Results:

• The proposed fringe segment splicing method significantly improves measurement resolution.
• Diameter measurements achieved a relative error of less than 0.1%.
• The method demonstrates superior performance compared to previous Fraunhofer diffraction measurement techniques.

Conclusions:

• Fringe segment splicing offers a robust solution for accurate thin filament diameter measurement via Fraunhofer diffraction.
• The method effectively mitigates the impact of system imperfections on measurement accuracy.
• This technique represents a substantial advancement in optical metrology for filament characterization.