A silicon carbide metalens with a focal length of 495μm operates simultaneously at both 860nm and 1240nm wavelengths. Until now, monolithic SiC metalenses were optimised for single wavelength colour centres, but Xiaoying Huang and colleagues from University of Technology Sydney have achieved dual-wavelength functionality within one device. This enables efficient light collection and manipulation from nitrogen vacancy and silicon vacancy defects concurrently.

The team has engineered a compact silicon carbide lens capable of simultaneously capturing light from two distinct atomic imperfections within the same material. This addresses a key challenge in building more sophisticated quantum systems by enabling concurrent operation without requiring separate components for each type of defect. Such multifunctional lenses offer a streamlined optical interface vital for developing smaller, scalable devices intended for applications like secure communication and advanced computation.

Xiaoying Huang and colleagues have created a silicon carbide metalens that can simultaneously capture light from two different types of atomic imperfections within the same material. These imperfections, known as nitrogen vacancy and silicon vacancy colour centres, act like artificial atoms emitting individual particles of light; they are tiny beacons embedded in the crystal structure of SiC.

This dual functionality overcomes limitations inherent in previous designs which typically focused on only one colour centre at a time, streamlining optical systems for quantum technologies. The team’s innovation offers a more compact design vital for building scalable devices intended for applications such as secure communication and advanced computation.

Dual wavelength metalens enables concurrent detection of colour centre emissions

A focal length of 495μm now defines a silicon carbide metalens capable of simultaneous operation at both 860nm and 1240nm wavelengths. Achieving independent phase control across distinct spectra within one structure unlocks efficient collection and polarization manipulation from nitrogen vacancy and silicon vacancy defects concurrently; this addresses spectral challenges inherent in SiC based quantum photonic devices.

The design integrates two adjacent 200×200μm sections tailored to each emission wavelength, enabling streamlined optical interfaces important for scalable integrated systems intended for applications like secure communication and advanced computation. Independently controlling light emitted at wavelengths of 860nm and 1240nm through tailored polarisation manipulation enabled simultaneous optically detected magnetic resonance from both silicon vacancy and nitrogen vacancy defects within the same SiC sample. Each section of the fabricated metalens, measuring 200×200μm, was specifically engineered to optimise performance for its designated wavelength.

This resulted in a collection half-angle of 21.8° and a numerical aperture of 0.97. The monolithic structure, created on a bulk SiC substrate with a height of just 1.6μm, represents strong miniaturisation compared to previous optical interfaces used with these colour centres. Current fabrication techniques do not yet address variations in defect placement or density across larger substrates; achieving uniform emission throughout an entire wafer remains the key hurdle before widespread practical application becomes viable.

Simultaneous capture of nitrogen and silicon vacancy centre emissions enables advanced photonic

Scientists at University of Technology Sydney have developed a metalens representing a major advance for silicon carbide based quantum technologies by simultaneously capturing light from both nitrogen vacancy and silicon vacancy defects. These imperfections within the material act as artificial atoms emitting individual photons important for applications like secure communication. This development simplifies device architecture, eliminating the need for separate optics previously required for each colour centre, moving beyond limitations that demanded discrete optical components optimised individually. The compact design and efficient collection capabilities allow streamlined integration into scalable systems; further work will focus on improving fabrication processes to ensure consistent defect placement across larger substrates, vital for realising fully functional wafers suitable for mass production of quantum photonic devices.

Scientists fabricated a monolithic metalens from silicon carbide capable of simultaneously collecting light emitted at wavelengths of 860nm and 1240nm from nitrogen vacancy and silicon vacancy defects. This enables optically detected magnetic resonance of both defects within the same sample, simplifying device architecture by removing the need for separate optics. Researchers intend to refine fabrication techniques to achieve uniform defect placement across larger substrates, which is necessary for scalable quantum photonic devices.

👉 More information
🗞 Engineering of Dual Wavelength, Polarization Selective Metalenses in Silicon Carbide
✍️ Xiaoying Huang, Ziwei Yang, Konosuke Shimazaki, Kritsana Saego, Otto Cranwell Schaeper, Evan Williams, Dragomir Neshev, Hark Hoe Tan, Igor Aharonovicha and Mehran Kianinia
🧠 ArXiv: https://arxiv.org/abs/2608.17506

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