Presentation description

A Multilevel Diffractive Lens (MDL) is a flat lens that uses multiple discrete phase levels or rings to efficiently focus light through diffraction, offering high performance and compactness. MDLs are significantly thinner and lighter compared to traditional diffractive lenses including the Fresnel Zone plate (FZP). This makes them ideal for applications where space and weight are critical constraints. However, the fabrication of the MDL is challenging, and there remains ongoing debate within the photonic community regarding whether their performance justifies replacing the much simpler FZP. FZPs are another type of diffractive lens that focus light using a binary structure of concentric rings with alternating transparent and opaque zones. FZPs are known for their simplicity in design and manufacturing and have been used in a wide variety of applications for many decades unlike the MDL. If proven that the MDL performs better at a high numerical aperture then it will demonstrate that their manufacturing challenges are justified for achieving higher-resolution focusing, minimal signal loss, and versatility. This would allow further innovation and improvements in imaging systems, miniaturized optical devices, laser beam shaping, and fiber optics. This project compared MDLs and FZPs at a high NA focusing on diffractive efficiency, resolution, and overall performance. Their performances were compared in simulation. This analysis provides insights into the advantages and limitations of both MDLs and FZPs in various optical applications. By comparing the MDL with the FZP, the project aimed to identify scenarios where one lens type outperforms the other, thereby guiding the selection of the most suitable lens for specific applications. This project was done under the mentorship of Dr. Rajesh Menon, funded by the SPUR program . I strongly believe that this project contributes significantly to the photonic community's understanding of the performance characteristics of advanced diffractive lenses and will drive further photonic innovation.