"The reusable template simplifies replication and increases production throughput, offering weight, cost, and scalability advantages over glass components."
A New Method for Making Full-Color Metalenses
A study published in Nature Communications on April 9, 2025, describes a breakthrough method for fabricating achromatic metalenses designed for use in full-color OLED near-eye displays. The technique combines grayscale electron-beam lithography, dry etching, and nanoimprint lithography to create polymer-based metalenses with independently controlled meta-atom dimensions.
Method and Design
The fabrication process utilizes a height-encoded nano-template to produce metalenses on flexible PET substrates. The approach introduces height as an additional design parameter to expand phase control, enabling multiwavelength correction on a low-index resin platform. The authors state that the reusable template simplifies replication and increases production throughput, and claim that the printable polymer-based metalenses offer weight, cost, and scalability advantages over glass components.
Optical Performance
Optical characterization demonstrated diffraction-limited focusing at red (635 nm), green (532 nm), and blue (450 nm) wavelengths. The focal plane deviations were measured below 7 µm from the designed 1.8 mm focal length. Measured focal spot sizes deviated less than 10% from simulations.
Strehl ratios—a key metric for image quality—were recorded as:
- 0.83 (blue)
- 0.86 (green)
- 0.85 (red)
All values are above the 0.8 diffraction-limited threshold. The metalens maintained an average effective numerical aperture of approximately 0.29, with focusing efficiencies of:
- 14.8% (blue)
- 11.3% (green)
- 12.3% (red)
Application Demonstration
The metalens was integrated into a prototype virtual reality imaging system with an OLED display and CMOS sensor, demonstrating full-color image formation with reduced chromatic blur.
Background Context
Metasurfaces enable precise light control but have exhibited chromatic aberration in full-color applications. Existing achromatic designs have required complex nanostructures or high-precision alignment, posing challenges to scalability.