新研究有望突破传统探针尺寸对分辨率的限制

Core Insights - The research teams from Xiamen University and National University of Singapore have made significant advancements in the study of lanthanide-doped photon avalanche upconversion nanocrystals, with results published in Nature on June 18 [1] Group 1: Research Findings - Photon avalanche is a unique optical nonlinear phenomenon in lanthanide-doped materials, characterized by a steep power-law relationship between light emission intensity and pump power, allowing for significant changes in emission intensity from minimal disturbances [1] - The research team developed a high-performance testing platform for studying photon avalanche effects, integrating automated systems for precise laser power control and high temporal resolution fluorescence signal collection [1] - By manipulating the lattice structure within the nanocrystals, researchers induced crystal field distortion in the avalanche ion network, achieving over 500 orders of optical nonlinear response, marking a new phase in the design of nonlinear optical materials focused on crystal structure engineering [1] Group 2: Material Performance - Replacing Y3+ ions with smaller Lu3+ ions effectively controls the arrangement of vacancies and ions within the crystal, accelerating the cross-relaxation process during photon avalanche [2] - The optical nonlinearity of 27 nm particles was enhanced to 156, with avalanche response time reduced to 8.5 milliseconds, approximately 1/70 of traditional core-shell structured nanocrystals, demonstrating excellent rapid response characteristics [2] - In a continuous wave laser scanning imaging system, the material achieved lateral resolution of 33 nm (about 1/33 of the wavelength) and axial resolution of 80 nm (about 1/13 of the wavelength), with a signal-to-noise ratio greater than 20 and positioning accuracy of 0.36 nm, indicating potential for low-cost super-resolution imaging applications [2] Group 3: Breakthroughs in Imaging - The research team expanded the photon avalanche positive feedback network, achieving over 500 orders of optical nonlinear response in a 176 nm diameter photon avalanche nanodisk [2] - The study revealed differences in regional responses of the photon avalanche effect within individual nanoparticles during laser scanning, enabling "imaging sizes smaller than physical sizes," which may overcome traditional probe size limitations on resolution [2]