Achromatic varifocal metalens enabled by polarization-dependent superposition.

Area of Science:

• Optics and Photonics
• Metamaterials
• Nanotechnology

Background:

• Traditional varifocal metalenses face limitations in size, tuning complexity, and chromatic aberration, hindering broadband use.
• Chromatic aberration is a significant challenge in optical systems, leading to reduced image quality and performance across different wavelengths.

Purpose of the Study:

• To propose and demonstrate a single-layer achromatic metalens with polarization-dependent focal length.
• To overcome the limitations of traditional metalenses, particularly chromatic aberration and bulky dimensions.

Main Methods:

• Utilizing interference of multi-atomic units with stable intensity superimposition to achieve achromatic focusing.
• Designing a single-layer metalens structure for polarization-dependent focal length control.

Main Results:

• Achieved achromatic focusing over a broad wavelength range (10-11.5 μm).
• Demonstrated tunable focal length from 0.93 to 1.05 mm with low coefficient variation (<1.75%) by adjusting incident light polarization.

Conclusions:

• The proposed single-layer achromatic metalens effectively addresses chromatic aberration.
• The polarization-tunable focal length offers a new avenue for developing compact and versatile optical imaging systems.