Our work on miniaturised meta-optical light emitters continues to push boundaries—with collaboration at its core. Teams across nodes, groups, partner and associate investigators, and international collaborators are joining forces to accelerate progress.
At ANU, the pioneering work on shape-engineered nanostructures is being developed further into arrays of nanosheet pairs. By carefully introducing asymmetry into these nanosheets, researchers can break the natural symmetry and enable room-temperature laser operation. This operates in quasi-bound states in the continuum, achieving a high-quality factor. Optimising this asymmetry brings us closer to thresholdless lasing—a breakthrough in efficiency.
Another focus is on semiconductor nanowire lasers. By coupling the emission from multiple nanowires, researchers can control directionality and beam profiles. Scaling this to large arrays creates photonic crystal surface-emitting lasers, including innovative hetero-lattice designs where an outer array enhances light confinement.
Progress also continues on electrically injected nanoscale lasers, such as microring lasers and top-down bound states in continuum lasers. One challenge lies in minimising optical losses caused by doped regions and contact layers. While LEDs have already been demonstrated, the next milestone is achieving full lasing—something the team is confident about with further optimisation.
Collaboration is also driving innovation in photonic integration. One project involves embedding semiconductor nanowire lasers into silicon nitride waveguides and beam splitters, a step toward practical photonic integrated circuits.
The collaboration between ANU and UTS has successfully demonstrated single quantum dots integrated into nanowire arrays, showing excellent single-photon emission. Meanwhile, UTS leads in hexagonal boron nitride (hBN) technology, working with RMIT and Cambridge collaborators. Their research has identified spin defects in hBN that could enable room-temperature spin qubits, paving the way for scalable quantum registers and nanoscale quantum sensors.
In the field of nonlinear metasurfaces, the ANU team—partnering with Melbourne and Jena—has made significant breakthroughs. They have demonstrated infrared quantum imaging and the up-conversion of infrared to visible light using an ultra-compact metasurface chip. These advances open doors to practical applications, including:
Low-light imaging
LIDAR technology
Miniaturised night-vision goggles
In summary: this phase is about more than just developing devices—it’s about weaving together expertise across disciplines and institutions. From lasers that operate at room temperature to quantum sensors and compact imaging systems, collaboration is proving to be the catalyst for innovation in meta-optics.
KEY ACHIEVEMENTS 2024:
- Experimental characterization of VB- spin defects in boron nitride nanotubes.
- Experimental demonstration of single-photon emission from quantum dots coupled with nanowires with high brightness and purity.
- First demonstration of quantum imaging using photon pairs generated from nonlinear metasurfaces.
- Experimental demonstration of infrared imaging with high quality factor resonant metasurfaces.
GENERATE Subprograms
This theme supports two sub-programs aimed and developing new meta-optical light emitters
Subprogram 1A – Nanoscale Lasers and Laser Arrays
Theme 1A is all about creating nanolasers and miniaturised light emitters that can be finely tuned for emission and wavefront control. These aren’t just impressive in theory—they’re essential tools for next-gen light manipulation and detection technologies. A big part of this vision also includes making nanolasers work with electrical pumping, which would make them easier to integrate into real-world devices.
This year, TMOS researchers achieved a world-first: a bottom-up fabricated metasurface laser based on bound states in the continuum (BICs). Why is this important? The bottom-up approach delivered exceptional surface quality in the nanoresonators, leading to low-threshold lasing. These metasurface lasers are excellent building blocks for tailored emission and wavefront engineering, paving the way for versatile light-based applications.
Another highlight came from work with semiconductor nanowires. Researchers designed photonic crystal lasers with hetero-lattices, where a tiny surface-emitting region is surrounded by a mirror-like photonic crystal. This clever design not only trapped light more effectively but also dramatically reduced lasing threshold power. Even better, it enabled the use of ultra-small surface-emitting regions, shrinking devices further without sacrificing performance.
On the electrical side, progress was made with microring lasers containing multiple quantum wells. Electroluminescence was successfully demonstrated—a key milestone. With a few more tweaks currently under investigation, these microring structures are expected to operate as fully functional miniaturised electrical lasers.
The year 2024 was a productive one for Theme 1A. From record-breaking metasurface lasers to advances in nanowire designs and electrical pumping, each achievement moves us closer to the vision of compact, efficient, and easily integrated nanolasers. These devices are not just lab curiosities—they are laying the groundwork for future technologies in optical communications, sensing, imaging, and beyond.
Action Items for 2025:
- Bottom-up fabricated nanolaser arrays for tailorable emission
- Development of electrical UV nano-emitters
- Electrically injected light-emitting metasurface
- Perovskite-based metasurface light-emitters
Subprogram 1B – Advanced and Quantum Light Sources
2024 has been a landmark year for collaboration across research nodes in Theme 1B. By pooling expertise from multiple institutions, teams achieved breakthroughs that bring us closer to real-world applications in quantum technologies and advanced imaging.
A joint project between UTS and ANU successfully grew single InP quantum dots within selectively grown nanowire arrays using the droplet epitaxy technique. These quantum dots showed outstanding single-photon emission—high brightness and purity, even at low excitation powers. This makes them highly promising for quantum communication and secure information transfer.
In another collaboration, UTS and RMIT investigated VB– spin defects in boron nitride nanotubes (BNNTs). Unlike their counterparts in hexagonal boron nitride (hBN) flakes, these spin defects naturally align with external magnetic fields, thanks to the tubular geometry of BNNTs. This property opens up exciting possibilities for room-temperature applications in night vision, sensing, and multi-colour imaging. The work also involved international collaboration with Friedrich Schiller University Jena.
Meanwhile, ANU and the University of Melbourne demonstrated how nonlinear metasurfaces can transform infrared quantum imaging. By integrating ghost imaging techniques with all-optical scanning, they created an efficient new protocol that could one day enhance low-light and biomedical imaging systems.
The UTS and ANU teams also co-authored a comprehensive review on flat optics for quantum light generation. This work explored the latest advances in entangled photon pair production in nonlinear metasurfaces, as well as single-photon emission from quantum dots and colour centres in both 2D and 3D materials.
Finally, the ANU team achieved a significant milestone by realising infrared imaging through nonlinear up-conversion. Using a compact, high-quality lithium niobate resonant metasurface, they were able to convert infrared signals into visible light, paving the way for practical, miniaturised imaging devices.
Action Items for 2025:
- Nonlinear Frequency Conversion in TopologyOptimised Dielectric Metasurfaces.
- Couple QD emission into whispering-gallery mode of InP-micro-ring resonator
- Electrically driven single photon source of quantum dots in single nanowire
- Optically tunable generation of biphoton polarization entanglement from an InGaP nonlinear metasurface
Generate - Research Program Manager
Wei Wen Wong
Research Fellow
Australian National University
Acknowledgement of Country
The ARC Centre for Transformative Meta-Optical Systems (TMOS) acknowledges the Traditional Owners and their custodianship of the lands on which our teams operate. We pay our respects to their Ancestors and their descendants, who continue cultural and spiritual connections to Country. We recognise their valuable contributions to Australian and global society.