Metasurfaces are a type of flat optics that leverage subwavelength features to control light. Metalenses, a type of metasurface, have emerged as a breakthrough technology to enable compact and efficient optical devices, whereas classical optical elements tend to be bulky. For many applications, polarization-insensitive metasurface are highly desirable. Current metalens technologies are either polarization-sensitive (i.e. only focus light with certain type of polarization), or, are polarization-insensitive but have a restricted design space. Researchers from the Capasso lab have developed a novel polarization-insensitive metalens based on anisotropic titanium dioxide nanofins. This design offers additional control over the dispersion and phase of the output light.

Advantages of this metalens over existing technologies include:

• Anisotropic design offers better dispersion control
• Diffraction limited spot for broadband operation
• Polarization insensitivity across the entire visible spectrum

This technology can be implemented in applications where polarization insensitivity is crucial, such as microscopy, imaging, virtual reality/augmented reality (AR/VR), or polarization-sensitive lithography.

This work has been published in Nature Communications.