Resolution of two problems in the Fourier analysis of thin films

Area of Science:

• Materials Science
• Optics
• Computational Physics

Background:

• Traditional Fourier transform methods for thin film synthesis face challenges with approximations in reflectance or transmittance data.
• Existing methods often yield distorted frequency and amplitude scales, particularly in high-reflectance scenarios.
• These distortions hinder accurate thin film characterization and deposition.

Purpose of the Study:

• To identify and resolve the difficulties encountered in applying the Fourier transform method to thin film synthesis.
• To establish a more accurate function for transformation in thin film analysis.
• To eliminate frequency and amplitude distortions in Fourier-transformed results.

Main Methods:

• Investigated the suitability of reflectance and transmittance functions for Fourier transformation.
• Analyzed the impact of multiple reflections on the accuracy of transformed data.
• Proposed and validated the use of reflectance amplitude as the primary function for transformation.

Main Results:

• Demonstrated that the reflectance amplitude is the appropriate function for Fourier transformation in thin film synthesis.
• Showed that incorporating multiple reflections effectively eliminates distortions in both frequency and amplitude scales.
• Achieved accurate results for thin film analysis, overcoming limitations of previous approximations.

Conclusions:

• The accurate synthesis of thin films using the Fourier transform method requires transforming the reflectance amplitude.
• Accounting for multiple reflections is crucial for mitigating distortions and ensuring precise frequency and amplitude scaling.
• This refined approach enhances the reliability of Fourier transform techniques in thin film deposition and characterization.