Evolutionary optimization of compact dielectric lens for farfield sub-wavelength imaging

Area of Science:

• Optics and Photonics
• Nanotechnology
• Materials Science

Background:

• Conventional optical lenses are limited by diffraction, hindering subwavelength imaging.
• Beating the diffraction limit is a long-standing challenge in optical microscopy and imaging.

Purpose of the Study:

• To design modified solid immersion lenses capable of subwavelength imaging.
• To achieve magnified imaging of objects with resolution beyond the diffraction limit.

Main Methods:

• Utilized a combination of transformation optics forward design and inverse design schemes.
• Employed an evolutionary optimization procedure to determine material parameters for matching layers.
• Designed a compact lens with a radius of 2.5 wavelengths.

Main Results:

• Achieved subwavelength imaging with a resolution as fine as lambda/6.
• Demonstrated precise recovery of object information, particularly for asymmetric shapes.
• Successfully delivered subwavelength information into the far field for magnified imaging.

Conclusions:

• The developed modified solid immersion lenses enable far-field subwavelength imaging at optical frequencies.
• The compact dielectric devices offer a significant improvement over previous methods, especially for complex object shapes.