A metalens is an ultrathin, flat optical element engineered from arrays of nanostructured pillars—often referred to as “meta-atoms.” Each meta-atom is precisely designed to induce a phase shift on incoming light by sub-wavelength interactions. By tailoring the geometry, orientation, and arrangement of these nanoscale features across the lens surface, metalenses can focus the light, and manipulate the light in new ways, not possible with conventional optics.

Metalens, diffraction grating
Fused silica substrate used for fabrication of metalenses.

Metalenses differ from conventional lenses—which rely on curved glass or plastic to refract light—by using diffraction and interference. Because meta-atoms can be fabricated with nanofabrication processes, metalenses offer dramatic size and weight reductions, high-volume manufacturability, and integration with on-chip photonics. They are often just tens to hundreds of nanometers thick, compared to millimeters or centimeters for traditional optics, however, generally require a thicker optical-grade substrate. They can be designed for visible, and other wavelengths.

Key Advantages

  • Aberration Correction: Metalenses can compensate for chromatic and spherical aberrations by spatially varying the nano-feature design, enabling achromatic focusing over broad bandwidths.
  • Compactness: Their planar form factor is ideal for ultrathin cameras, wearable displays, or compact endoscopes.
  • Integration: Compatibility with semiconductor fabrication allows direct integration into image sensors, lab-on-a-chip systems, and photonic circuits.
  • Custom Wavefront Control: By encoding arbitrary phase profiles, metalenses can generate vortex beams, perform holography, and implement optical trapping.

Applications

Metalens with Cladding
Metalens 3d model (typically there are thousands of pillars used)
  1. Computational Imaging and Photography Metalenses enable flat, ultracompact camera modules for smartphones and surveillance devices. Their aberration-corrected, broadband performance simplifies optical stacks and reduces the number of elements needed.
  2. AR/VR and Wearable Displays Their low profile makes metalenses ideal for head-mounted displays and smart glasses, where volume and weight are at a premium. They can focus and collimate light from micro-LED arrays with minimal distortion.
  3. Biomedical Endoscopy Tiny metalens-enabled probes fit within catheters or needles to deliver high-resolution imaging directly inside the body. Achromatic metalenses ensure clear, color-accurate images without bulky lens assemblies.
  4. Photonic Circuits and On-Chip Optics Metalenses can focus, split, or shape light on-chip, paving the way for compact spectrometers, LiDAR systems, and optical neural networks integrated onto silicon wafers.
  5. Optical Trapping and Micromanipulation By generating complex beam profiles such as optical vortices, metalenses facilitate contactless manipulation of microscopic particles in lab-on-a-chip platforms.

Future Impact

As fabrication techniques advance, metalenses are poised to transition from lab demonstrations to mass-market products. Ongoing research targets large-area manufacturing, active tunability (via liquid crystals or MEMS), and multi-functional metasurfaces that combine lensing, filtering, and sensing in a single platform. Within the next decade, metalenses could redefine optical design, unifying disparate elements into monolithic, wafer-scale chips.

If you’d like to explore how metalenses might revolutionize a specific application—whether in consumer electronics, biomedical imaging, or quantum photonics—reach out to us, and we can help with the design and fabrication for prototyping and higher volume manufacturing.

Helpful References

  1. Khorasaninejad, M. & Capasso, F. “Metalenses: Versatile Multifunctional Photonic Platforms.” Science (2017).
  2. Chen, W.T. et al. “Achromatic metasurface lens at visible wavelengths.” Nature Communications (2018).
  3. Prakash, A. et al. “Flat optics for endoscopic imaging.” Nature Biomedical Engineering (2020).