Key Points
- Researchers achieved a complete photonic bandgap in 3D photonic crystals printed using customized titanium resin and TPL.
- The process involves transforming titanium into high-refractive-index titania. This breakthrough allows precise 3D control of light in the visible spectrum.
- Potential applications include telecommunications, sensing, and quantum technologies.
- The method may be adapted for fabricating nanoscale materials like glass and metals.
In a significant advancement for photonics, researchers from the Singapore University of Technology and Design (SUTD) and Chinese institutions have developed a method to print 3D photonic crystals with a complete photonic bandgap across the visible light spectrum. The research was published in Nature Nanotechnology.
Photonic crystals are materials with repeating internal structures that uniquely interact with light. Despite being made of transparent materials, these crystals can block certain wavelengths of light due to a property known as the photonic bandgap. A complete photonic bandgap blocks light from all directions, enabling precise light control. Until now, producing 3D photonic crystals with a complete bandgap in the visible range has been a significant challenge due to the complexity of fabricating these structures at the nanoscale.
The SUTD team overcame these challenges by using a customized titanium resin to print the crystals via two-photon polymerization lithography (TPL), a commonly used additive manufacturing technique. Titanium dioxide, or titania, was chosen for its high refractive index, a critical factor for achieving the complete bandgap. The organic components were removed by heating the printed crystals, and the titanium ions were oxidized to form titania, resulting in a structure with nanoscale precision.
The breakthrough opens new possibilities in telecommunications, quantum information processing, and sensor technologies. “These crystals allow for elaborate 3D control of light flow, which could revolutionise the behaviour of single-photon emitters and quantum technologies,” explained Dr. Zhang Wang, the study’s first author.
The ability to customize these structures using TPL also means the crystals can be tailored for various applications, including waveguides and color generation. Additionally, the technique holds promise for fabricating other nanoscale materials like glass and metals, broadening its potential impact on material science and nanotechnology. Prof Yang noted that this research reflects SUTD’s mission to combine multiple disciplines to create innovations that positively impact society.
