A research team led by Professor Liu Xiaogang from the Department of Chemistry at the National University of Singapore, in collaboration with Professor Liang Liangliang from Xiamen University, has published a groundbreaking study in Nature, successfully developing a class of lanthanide-doped nanomaterials exhibiting optical nonlinearity exceeding a factor of 500. This achievement sets a new benchmark for photon avalanche research.

Photon avalanche is a rare photophysical phenomenon characterized by an exponential surge in emission intensity when the excitation power surpasses a critical threshold. By introducing local crystal field distortion into lanthanide-doped nanocrystals, the research team significantly enhanced the energy transfer efficiency between thulium ions, thereby greatly increasing the optical nonlinear response of the material. Experimental data show that 27-nanometer nanocrystals exhibit a nonlinearity above 150, while 170-nanometer nanoplatelets reach values exceeding 500.

Professor Liu Xiaogang stated: "By combining the photon avalanche effect with precise nanomaterial design, we are redefining the boundaries of nonlinear optics." The material demonstrates exceptional optical amplification behavior, transforming minute variations in optical input into dramatic changes in emission intensity, opening new possibilities for ultra-sensitive detection.

Using this material, the research team achieved single-beam super-resolution imaging with a spatial resolution of 33 nanometers laterally and 80 nanometers axially, comparable to traditional complex microscopy systems. In addition, the material exhibits spatially differentiated nonlinear emission patterns within a single nanocrystal, overcoming the limitations imposed by physical size on imaging resolution.

This breakthrough brings new technological advances to fields such as biomedical imaging, quantum photonics, and data storage. The researchers noted that this cost-effective super-resolution imaging approach is expected to promote broader adoption of related detection technologies. The study also lays a material foundation for developing more sensitive and compact optical devices.