Fourier transform approach for thickness estimation of reflecting interference filters

Area of Science:

• Optics and Photonics
• Materials Science
• Thin Film Technology

Background:

• Dielectric thin film reflectors are crucial optical components.
• Accurate thickness estimation is vital for their performance.
• Existing methods may have limitations in precision or applicability.

Purpose of the Study:

• To propose and validate an empirical procedure for dielectric thin film reflector thickness estimation.
• To establish a parallel between optical-density-bandwidth methods and Fourier transform synthesis.
• To introduce novel Fourier-transform approaches for thin film analysis.

Main Methods:

• Utilizing optical-density-bandwidth products for thickness estimation.
• Applying Fourier transform thin film synthesis techniques.
• Developing and numerically demonstrating two Fourier-transform approaches.

Main Results:

• The proposed empirical procedure provides a viable method for thickness estimation.
• A clear parallel was established between the optical-density-bandwidth product and Fourier transform synthesis results.
• Numerical examples validated the effectiveness of the two new Fourier-transform approaches.

Conclusions:

• The optical-density-bandwidth product method offers a practical approach for dielectric thin film thickness determination.
• Fourier transform techniques provide powerful tools for thin film synthesis and analysis.
• The study introduces innovative Fourier-transform methodologies for enhanced thin film characterization.