Impact of fabrication errors and refractive index on multilevel diffractive lens performance

Area of Science:

• Optics and Photonics
• Metamaterials
• THz Technology

Background:

• Multilevel diffractive lenses (MDLs) offer versatile functionalities for imaging and display applications.
• Structural optimization enables advanced MDL features like achromaticity and wide-angle imaging.
• Understanding fabrication error impacts is crucial for MDL design and performance prediction.

Purpose of the Study:

• To statistically analyze the impact of fabrication imperfections on MDL performance.
• To evaluate the trade-off between efficiency and parameter selection before fabrication.
• To assess the influence of material refractive index on MDL performance.

Main Methods:

• Statistical simulation-based study of MDLs, primarily in the THz regime.
• Analysis of single and multiple fabrication imperfections as a function of ring height levels.
• Evaluation of MDL performance with varying material refractive indices.

Main Results:

• Quantified the impact of fabrication errors on MDL focusing efficiency.
• Demonstrated the relationship between fabrication imperfections and the number of height levels.
• Assessed the effect of refractive index variations on lens performance.

Conclusions:

• Fabrication errors significantly affect MDL performance, necessitating pre-design analysis.
• Focusing efficiency is a key metric for evaluating MDLs and guiding design optimization.
• This study provides insights for robust MDL design, particularly for THz applications.